Infrared Spectra and Characteristic Frequencies
of Inorganic Ions
Their Use in Qualitative Analysis
FOIL A. MILLER AND CHARLES H. WILKINS
Department of Research in Chemical Physics, Mellon Institute, Pittsburgh 13, Pa.
Polyatomic ions exhibit characteristic infrared spectra. Although such spectra are potentially useful,
there is very little reference to them in the recent
literature. In particular, the literature contains no
extensive collection of infrared spectra of pure inorganic salts obtained with a modern spectrometer.
In order to investigate the possible utility of such
data, the infrared spectra of 159 pure inorganic
compounds (principally salts of polyatomic ions)
have been obtained and are presented here in both
graphical and tabular form. A table of characteristic frequencies for 33 polyatomic ions is given.
These characteristic frequencies are shown to be
useful in the qualitative analysis of inorganic unknowns. Still more fruitful is a combination of
emission analysis, infrared examination, and x-ray
diffraction, in that order. Several actual examples
are given. It is evident that a number of problems
involving inorganic salts containing polyatomic ions
will benefit by infrared study. The chief limitation
at present is the practical necessity of working with
powders, which makes it difficult to put the spectra
on a quantitative basis.
A
LTHOUGH there has been a vast amount of work on the
Raman spectra of inorganic salts ( 2 , 4 ) , the study of them
in the infrared has been relatively neglected. Schaefer and Matossi (10) have reviewed work done up to 1930, most of which deals
with reflection spectra. The most extensive surveys of infrared
absorption spectra have been made by Lecomte and his coiTorkers
(6, 7 ) , but unfortunately many of their data are somewhat out
of date and are not always presented in the most useful form.
References to studies on a few ions are given in the books by Wu
(12) and by Herzberg ( 3 ) . There has recently been renewed
interest in the detailed study of the infrared spectra of selected
salts, as exemplified by the papers of Halford ( 8 ) , Hornig ( I I ) ,
and their coworkers. The well known Colthup chart ( 1 ) contains characteristic frequencies for nitrate, sulfate, carbonate,
phosphate, and ammonium ions. An excellent recent paper by
Hunt, Kisherd, and Bonham ( 5 ) contains the spectra of 64
naturally occurring minerals and related inorganic compounds.
Aside from sixteen spectra in this latter paper, there is in the
literature no compilation of infrared spectra of inorganic salts
obtained with a modern spectrometer. I t therefore seemed worth
while to make a fairly extensive survey to seek answers to the following questions: Is it generally possible to obtain good spectra?
Do the ions possess frequencies which are sufficiently characteristic to be useful for analytical purposes? What is the effect on
the vibrational frequencies of varying the positive ion? Is
infrared spectroscopy useful in the analysis of salts?
This paper presents the spectra from 2 to 16 microns of 159
pure inorganic compounds, most of which are salts containing
polyatomic ions. A chart of characteristic frequencies for 33 such
ions is given. The use of these data for the qualitative analysis
of inorganic mixtures is demonstrated. Finally, a number of
interesting or puzzling features of the spectra are described.
A brief classification of the various types of vibrations in
crystals may be appropriate. Ionic solids are considered fiist.
In a crystal composed solely of monatomic ions, such as sodium
chloride, potassium bromide, and calcium fluoride, the only
vibrations are “lattice” vibrations, in which the individual ions
undergo translatory oscillations. The resulting spectral bands are
broad and are responsible for the long wave-length cutoff in
transmission. I n a crystal containing polyatomic ions, such as
calcium carbonate or ammonium chloride, the lattice vibrations
also include rotatory oscillations. Of greater interest in this
case, however, is the existence of “internal” vibrations. These
are essentially the distortions of molecules whose centers of mass
and principal axes of rotation are a t rest. The internal vibrations
are characteristic of each particular kind of ion.
I n molecular solids, such as benzene, phosphorus, and ice, the
units are uncharged molecules held in the lattice by weak forces
of the van der Waals type, andoften also by hydrogen bonds. The
same classification into internal and lattice modes can be made.
A few examples of such solids are represented in this paper (boric
acid, and possibly the oxides of arsenic and antimony).
Finally there are the covalent solids, such as diamond and
quartz, in which the entire lattice is held together by covalent
bonds. Here the distinction between lattice and internal vibrations disappears. One might a t first expect an ill-defined and
featureless spectrum, but such is not the case. Actually there
are bands that are very Characteristic. The situation is in
some ways analogous to that in a polymer, which in spite of its
size and complexity possesses a remarkably discrete spectrum.
Silica gel is the only representative of this type included here.
EXPERIMENTAL
Origin and Preparation of Samples. Practically all the samples
were commercial products of C.P. or analytical reagent grade.
The samples were gound to a fine powder to minimize the scattering of light, and were examined as Sujol mulls. When there were
spectral features that were obscured by the Sujol bands, the
samples were either run as a dry powder or mulled in fluorolube (a
mixture of completely fluorinated hydrocarbons. Fluorolube is
a product of the Hooker Electrochemical Co., perfluoro lube oil
of E. I. du Pont de Semours & Co.). Some compounds, such
as ferric nitrate nonahydrate (No. 49) and calcium permanganate
tetrahydrate ( S o . l50),seemed to mull up in their own water of
hydration. When the fine powder x a s rubbed between salt
plates, it acquired the appearance and feel of a typical mull, but
no appreciable fogging of the salt plates resulted. For other compounds, such as potassium carbonate, breathing on the sample
achieved the same result. This is not recommended, however,
for it varies the water content unnecessarily, and with potassium carbonate some of the bands are shifted.
Although these techniques are satisfactory for qualitative
examination, it may be of interest t o list some other methods
which have been mentioned in the literature for handling inorganic solids. Lecomte, who introduced most of them, has pointed
out that a finely ground dry powder scatters very little radiation
of wave length greater than 6 microns and consequently it may
be used directly in that region (6, 7 ) . He also suggests coating
1253
ANALYTICAL CHEMISTRY
1254
Table I.
Index to Infrared Curves and Tables of Data
Formula
Boron
hletaborate
No.
1
2
3
Tetraborate
Type
Sulfur (Contd.)
Sulfate
Formula
No.
4
5
6
Perborate
7
Misc.
8
9
Carbon
Carbonate
PbCOa
SHiHCOa
NaHCOa
KHCOa
10
11
12
13
14
15
16
17
18
19
20
Cyanide
NaCN
KCY
21
22
Cyanate
KOCX
AgOCN
23
24
Thiocyanate
NHISCN
NaSCN
KSCN
Ba(SCN)z. 2Hz0
Hg(SCS)z
Pb(SCN)z
L1&03
NazCOz
KzCOa
3hfgCOs hlg(OH)n.3HzO
CaCOa
BaCOa
coco3
Bicarbonate
Silicon
Metasilicate
Silicofluoride
Silica gel
Sitrogen
Nitrite
31
32
NazSiFs
SiOr , XHZO
33
34
Nah-02
KNO?
AgNOz
Ba(SOz!z Hz0
36
36
37
38
Nitrate
Subnitrate
39
40
41
42
43
44
45
46
47
48
49
BiOSOz.Hz0
Phosphorus
Phosphate, tribasic
Phosphate, dibasic
Thiosulfate
Metabisulfite
60
61
62
63
64
65
Selenium
Selenite
104
105
106
NazSeOa
CuSeOa, 2H20
107
108
Selenate
(NHhSeOi
NazSeOi. lOHzO
KzSeOh
CuSeOl. 5HzO
109
110
111
112
Chlorate
NaC108
KClOa
Ba(Cl0s)z.Hz0
113
114
115
Perchlorate
NHiClOi
SaClOa, H20
KClOa
Mg(CIO*)z
116
117
118
119
NaBrOa
KBr03
AgBrOa
120
121
122
Bromine
Bromate
Iodine
Iodate
Periodate
123
124
125
KIOi
Vanadium
Metavanadate
Chromium
Chromate
Dichromate
Molybdenum
Molybdate
Heptamolybdate
Tungsten
Tungstate
Manganese
Permanganate
66
67
68
103
Persulfate
50
51
52
53
54
55
56
67
58
59
(NHdzHPOi
hazHPOi.12HzO
KiHPOi
MgHPOi. 3Hz0
CaHPOa. 2H20
BaHPOi
Bisulfate
Complex ions
Ferrocyanide
126
127
128
(NHl)zCrOa
NazCrOi
KzCrOa
MgCrO4.7HzO
BaCrOb
ZnCrOa, 7HzO
PbCrOa
Alr(CrOd8
129
130
131
132
133
134
135
136
(NH4)zCrzOi
NazCrtO~.2H20
KzCrrOr
CaCrzOl.3HzO
CuCrzOr ,2Hz0
137
138
139
140
141
NazMoOi, 2HzO
Kd~foOi.5HnO
142
143
(~Hdahfo7O24.4HzO
144
NanWOi.2HzO
KzWOI
CaWOi
145
146
147
NaMn04.3HzO
KMnOi
Ca(MnOi)*.lHzO
Ba(Mn0h
148
149
150
151
152
153
154
155
71
Ferricyanide
NarFe(CN)a. 10HzO
KdFe(CN)o.3Hn0
c a ~ F e ( C N ) a12Hz0
.
KaFe(CN)s
Orthoarsenate, tribasic
Orthoarsenate, dibasic
Car(.4sOi)z
NazHAsO4.7HzO
PbnHAsOi
72
73
74
Cobaltinitrite
NasCo(N0r)o
156
Hexanitratocerate
(NHdzCe(N0ah
157
Orthoarsenate, monobasic
KHz.4~04
75
Oxide
AszO:
76
NHhCl
BaCln. 2Hz0
158
159
Nujol, fluorolube
160
SbzOa
Sbzos
77
78
(NHI)ZSOSHzO
NazSOa
KzSOa 2Hz0
CaSOa 2Hz0
BaSOa
ZnSOs 2H20
79
80
81
82
83
84
69
70
Antimony
Oxide
Sulfur
Sulfite
Chlorine
Chloride
Mulling agents
V O L U M E 24, NO. 8, A U G U S T 1 9 5 2
Table 11.
v w = very weak
w
=
weak
C m . - 1 Microns
I
1. Sodium metaborate
NaBOz
862
11 60 w
925
10 80 vs, b
8 50 ni
1175
1310
7 64 rs
1655
6 05 m
3470
2 85 YS, vb
2.
M a nesium metaborate
M%Bo~)~.~H~o
808
838
892
952
1005
1085
1130
1220
1370
1420
1640
3360
3500
12.4
11.95
11.2
10.5
9.95
9.2
8.8
8.2
7 3
7 05
6 1
2 98
2 86
3.
960
1340
1380
3280
4.
~~
5.
w
s
s
w
s
s
Lead metaborate
Pb(B0z)n. HzO
1 0 . 3 s, vb
7.45 m
7.2
Nujol?
3.05 m
Sodium perborate
NaBOs.4HzO
vw
13 0
w
12 0
11 75 w
vw
11 4
TS
10 7
9 8
8
9 3
m
8 5
s
8 05 s
6 05 w
vs
3 0
Boric acid
&BO3
12.4
m
vw
11 3
8.37 s,sp
6.9
vs
3.15 s
8.
807
885
1195
1450
3270
s
Manganese tetraborate
MnBiOi.8HzO
10.1
9 . 4 1 s , vb
8.7
7.3
s
6.9
m
6.1
w
2.95 8
7.
770
833
852
877
934
1020
1075
1175
1240
1655
3330
m
Potassium tetraborate
K2BiOi. 5Hn0
14.2 vw
12.8 vw
12.0 s
10.9 s
10.0 s
9.45 vw
9.2 s
8.85 v w
8.65 w
8.05 m
7 . 6 2 sh
7.45 s
6.95 s
6.05 w
4 03 vw
3.03 s
2.95 s
2.81 s
705
782
833
918
1000
1060
1085
1130
1155
1240
1315
1340
1440
1655
2480
3330
3390
3560
990
1065
1150
1370
1450
1640
3390
w
s
Sodium tetraborate
NazBiOi. lOHzO
14.05 w
12.9
w
12.1 s
10.6 s
10.0 s
w
9.3
8.85 m
7.95 m
7.85 m
7.35 vs
7.05 vs
6.85 Nujol?
6.05 m
3.0
vs
712
775
828
843
.
1000
1075
1130
1260
1275
1360
1420
1460
1650
3330
6.
s
m
vw
1255
Positions and Intensities of Infrared Absorption Bands
s = strong
m = medium
verystrong s h = shoulder b = broad
= KBr region (15-25~) eyamined
vs =
*
Microns
I
9. Boron nitride
BN
810
12.35 w
1390
7.2 s
Cm. -1
Lithium carbonate
LipCOp
1 1 . 5 8 in
6.92 s
6.7
s
10.
864
1445
1490
11.
700
705
855
878
1440
1755
2500
2620
-3000
Sodium carbonate
NapCOa
14.3
in
14.2 m
11.7 v w
11.4 s
6 . 9 5 vs
5.7
m, sp
4.0
m
3 . 8 2 vw
3.3
m, vb
-
12. Potassium carbonate
KzCOa
865
11.55 m
1 1 . 1 vw
900
6.9
vs
1450
-3220
3.1
m, vb
-
13. M a nesium carbonate basic
3 M g e O ~Mg(OH)n.3H;O
.
1 2 . 5 vw
800
11.7
vw
855
vw
885
11.3
7
.
0
vs
1430
vs
1490
6.7
2.9
111, vb
3450
14.
Calcium carbonate
CaCOa
14.0 w
11.4 s , s p
7 . 0 vs
5.6
vw
3.95 vw
715
877
1430
1785
2530
15. Barium carbonate
BaCOa
697
1 4 . 3 5 vi
858
11.65 s , s p
6 . 9 5 vs
1440
16.
747
865
1450
-3330
Cobaltous carbonate
COCOS
1 3 . 4 vw
11.55 m
6.9
vs
3 . 0 w , vb
17.
685
840
1410
18.
703
832
993
1030
1045
1325
1400
1620
1655
1890
2550
3060
3160
19.
662
698
838
1000
1035
1050
1295
1410
1460
1630
1660
1900
2040
2320
2500
2940
Lead carbonate
PbCOa
14.6 w
1 1 . 9 vw
7.1
YS
Ammonium bicarbonate
NHiHCOi
14.25
12.02
10.08
9.7
9.58
7.55
7.15
6.17
6.05
5.3
3.92
3.27
3.17
s
s, sp
s
w, SP
w , SP
vs, b
vs, s p
s
s
w
m
VS,SP
20.
705
833
990
1010
1370
1410
1630
2380
2600
2950
E}
5.27 m
5
vw
w (COZ?)
s. b
hficrons
I
Potassium bicarbonate
KHCOa
14.2 s
12.0 s , s p
10.1 s
9.9 9
m, sh
7.3
vs
7.1
6 . 1 5 vs
4.2
w
3 . 8 5 s , vb
3.37 m
s p = sharp
22. Potassium cyanide
KCN (KHCOa, K ~ C O Simpurities)
1 2 . 0 m , imp.
833
882
11.35 vw, imp.
1440
6 . 9 5 s , imp.
1635
6.12 8
2070
4.83 s
23. Potassium cyanate
KOCN (KHCOa impurity)
706
833
980
1010
1210
1310
1410
1640
2130
2630
1210
1310
1345
2170
3450
25.
1420
1650
2050
2860
3060
3149
26.
758
950
1620
2020
3330
27.
746
945
1630
2020
3400
28.
1630
2060
3500
29.
835
1105
1150
1370
1615
2090
3450
14.17
12.0
10.2
9.9
8 25
7.65
7.1
6.1
4.7
3.8
s. imp.
s,rmp.
m, !mp.
m , imp.
m , sp.
n', s,p.
v s , !mp.
vs, imp.
s , yb
s , imp.
24. Silver cyanate
AgOCN
8 . 2 5 vw
7.65 w
7 . 4 3 vw
vs
4.6
2.9
vw
Ammonium thiocyanate
NHiSCN
7.05 s
6 05 m
4 88 s
3.5
m
3.27 s
3.18 s
Sodium thiocyanate
NaSCN
w
13 2
vw, b
10 5
6 18 m
8
4 9
ni
3 0
Potassium thiocyanate
KSCN
13.4
m
10.6
vw, vb
6.13 m
s
4.9
2.95 m
Barium thiocyanate
Ba(SCN)z. 2HzO
6.15 m
4 . 8 5 vs, s p
2 . 8 5 vs
Mercuric thiocyanate
Hg(SCN)z
1 2 . 0 vw
9 . 0 5 vw
vw
8.7
s
7.3
w
6.2
4.78 8
2.9
w
30. Lead thiocyanate
Pb(SCN)E
2030
4.93 8. sp
w
2080
4.8
imp. = impurity
Cm. -1 Microns
I
31. Sodium metasilicate
NarSiOa. 5Hz0
715
14.0 s
775
12.9 s
832
12.03 s
980
10.2
YS
8.9
m
1125
8.58 m
1165
5.9
m
1695
2330
4.3
m
3280
3 . 0 5 vs, vb
32.
21. Sodium cyanide
NaCN (NasCOa impurity)
11.55 m , imp.
865
1310
7 . 6 5 vw
1460
6 . 8 5 vs,imp.
6.1
m
1640
2080
4.8 s
4.5
w, vb
2220
3.0
m , vb
3330
vs, sp
Sodium bicarbonate
NaHCOs
1 5 . 1 5 w (COZ?)
14.35 R
11.95
10.0
9.65
9.55
7.73
7.1
6.85
4.9
4.3
4.0
3.4
Cm. -1
vb = verybroad
Potassium metasilicate
KtSiOa
13.0
vw
1 0 . 1 vs, vb
6.15 vw
3.0
m
770
990
1625
3330
33.
Sodium silicofluoride
Na2SiFa
13.73 v s
m,sh
12.7
9.05 vw
728
790
1105
34. Silica gel
SiOz. xHzO
12.5
10.55
9,l5
8.4
6.1
3.0
800
948
1090
1190
1640
3330
35.
s,sh
vw
m
Sodium nitrite
NaNOz
831
1250
1335
12.03
8.0
7.5
36.
w
w
vs
m, s p
vs
m,sh
Potassium nitrite
KNOz
830
1235
1335
1380
2560
3450
12.05 s , s p
8.1
vs
7 . 5 m, sp
7.25 m
3.9
vw
2.9
vw
37.
833
848
1250
1380
Silver nitrite
AgNOz
12.0 w
11.8 v w
vs
8.0
7.25 vs
38. Barium nitrite
Ba(N0n)z. H20
820
1235
1330
1640
3360
3510
12.2
8.1
7.53
6.1
2.98
2.85
39.
m , SP
;:i5}
6.13 w
5.75 w
w
3410
2.93
40.
836
1358
1790
2428
41.
824
1380
1767
42.
803
835
1348
m
m
m ,sp
Ammonium nitrate
NHiNOa
12.05 w
830
1340
1390
1630
1740
733
w
vs
Sodium nitrate*
NaNOa
11.96 m , s p
7.36 vs
5.59 v w
4.12 vw
Potassium nitrate
KNOI
12.14 m, s p
7 . 2 5 vs
5 . 6 6 vw
Silver nitrate
AgNOa
13.64 vw
12.45
11.98 w
vw
7.42 YB
ANALYTICAL CHEMISTRY
1256
Table 11.
vw = very weak
w = weak
Cm. - 1
RZicrons
I
43. Calcium nitrate
Ca(N0a)z
820
12.20 w
9.58 vw
1044
s
1350
7 4
1430
7.0 s
6.1
m
1640
s
3450
2.9
44.
13.72 6 , SP
12.24 S , S P
7 . 4 0 vs
7.05 m,sp
5 64 w, SP
4.15
b
UT,
46. Cupric nitrate
Cu(N0a)z. 3Hz0
11.96 w
7.26 vs
6.30 6, SP
5 58 v w
4 . 1 1 vw
3 15 w
2.98 s, b
47.
807
836
1372
1640
3230
3410
726
807
836
1373
Lead nitrate
Pb(N0a)z
13.77 u'
12.39 v w
11.96 w, sp
7.28 w
835
1361
1613
1785
2440
3230
49. Ferric nitrate
Fe(NOa)a,9HzO
11.98 w
7 . 3 6 vs
6.19 m
5.6
vw
4.1
vu.
3 . 1 s , vb
50.
816
1325
1380
1640
3390
*
1
55.
Manganese phosphate, tribasic
Mns(P0a)z. 7Hz0
935
10.7 vw, sh
980
10.2
w
1020
9.8 s
1040
9.6
?sh
1070
9.35 s
1145
8.75 w
1250
8.00 w
1300
7.7
w
2470
4.05 vw
3170
3,l5'!
3330
3450
i:: I
56.
Nickel(ous) phosphate, tribasic
Nia(P0a)~.
7Hz0
735
13.6
w. vb
877
11.4 w
Rh
943
io 6. w., .~.
100.5
9.95 s
1060
9 . 4 5 w, sh
-1440
?)
6 . 9 5 w (Sujol
1595
6.27 w
-3030
3.3
s
3450
2.9
m,sp
-
57.
+
Lead phosphate, tribasic
Pbs(P0a)z
59.
Chromic phosphate, tribasic
CrPOa. H?O
1030
9.7
vs, vb
1625
6.15 w
3230
3 . 1 E, b
60.
Ammonium phosphate, dibasic
(NHa)zHPOc
Potassium phosphate, tribasic
KaPOi
10.0 vs, vh
1000
6 . 3 w , vb
1590
3180
3.15 vs, b
53. Magnesium phosphate, tribasic
Mga(POajz.4HzO
768
13.05 w, b
887
1 1 . 3 vw, b
1%
1040
1135
1155
1230
1640
3260
3460
%E5]
8.83
8.65
8.13
6.1
3.07
2.9
,"
m
w,sh
w
m
s
m, s h
vb = very broad
sp = sharp
m
::::}
-
71.
64.
Calcium phosphate, dibasic
CaHPOa. 2H20
880
11.35, m
990
10.1
1050
9.5 1 s, r b
1125
8.9 J
1350
7.4
?
1650
6.07 m
-2270
4.4
m, vb
-3000
3.3
m
3610
2.85 v w , sh
65.
Sodium metaarsenite
NaAsO,
14.36 vs, b
13.35 m
12.9
w,ah
12.0 s, sp
11.8 s , s p
7.06 v w
6.85 m, sp
2.90 w , b
697
748
775
833
848
1420
1460
3450
--
72.
Calcium orthoarsenate,
tribasic
Ca,(AsO4)2
Barium phosphate, dibasic
BaHPOa
73.
2440
2700
66.
900
1080
1275
1420
1440
-1610
-2270
2900
3050
67.
4.1
3.7
w
w
Ammonium phosphate
monobasic
NHaHzPOa
11.1
w , vb
9.25 m, b
7.85 m
7.05 w, sh
6 . 9 5 rn
6.2
w, vb
4.4
w, vb
3 . 4 5 w, sh
3.28 m
--
Sodium phosphate, monobasic
NaH2POa. HzO
1640
2850
2820
Sodium orthoarsenate, dibasic
NazHAsOa.7HzO
712
836
1175
1280
1640
2175
2380
-3130
-
74.
Lead orthoarsenate, dibasic
PbzHAsOc
743
13.45 m , b
800
12.5
vs
75.
Potassium orthoarsenate,
monobasic
KHzAsOa
750
850
1020
1266
1585
-2275
-2740
--
6.1
m , vb
4 . 2 5 s, b
3.55 s , b
803
840
1040
77.
61.
Sodium phosphate, dibasic
NanHPOa. 12HzO
11,55 9
865
1 0 . 4 5 w, sh
958
10.15 S
985
1070
9 . 3 5 17s
1125
8.9
u-,sh
1145
8 . 7 5 vw, sh
1185
8 45 w
126.5
7.9 W
1630
6.13 m
-2220
4 . 5 w , vb
3280
3 . 0 5 vs, vb
-
62.
imp. = impurity
Cm.-' hlirrons
I
70. Calcium phosphate monobasic,
Ca(H2POa)z. ~ 2 0
670
14.9
m, vh
855
w, r b
885
915
10 9 ' v w , sh
950
10 5
s. h
1085
9 2
s,b
1160
8 6
w
1235
8 1 s,b
1640
6.1 m
2320
4.3
m, vb
-2980
3.35 s , v b
76.
51.
52.
35
Copper(icj phosphate, tribasic
C~a(POa)2.3Hz0
645
15.5 m
855
11.7 m
925
10.8 s
960
10.4 s
1010
9.9
s
1070
9.35 s
1100
9.1
m , sh
8.75 m
1140
7.75 m
1290
3390
2.95 m
58.
b = broad
Cm. -1 Microns
I
63. Magnesium phosphate, dibasic
MgHP04.3H20
882
11.35 m
1020
9.8
s
1055
9.5
s
1160
8 6
8
N
Bismuth subnitrate
BiONOa. H20
12 27 vw
7.55 s
7.25 vs
6.1
vw
2.95 m, b
Sodium phosphate, tribasic
NaaPOa. 12H20
694
1 4 . 4 real?
1000
1 0 . 0 vs
6.9
vw
1450
6.03 m
1660
3200
3.13 vs, b
ah = shoulder
= I<Br region (15-25p) examined
Microns
I
Calcium phosphate, tribasic
Caa(P0a)z
10.4 v w
962
1030
9 . 7 ' YS, vb
1085
9.2
3230
3 . 1 m, b
Cobaltous nitrate
Co(NOa)2.6HzO
12 4
vw, r b
11 96 w, 6p
7 29 vs
6 1 m
3 1
m , sh
2.93 s
48.
vs = very strong
54.
Barium nitrate
Ba(N0s)t
729
817
1352
1418
1774
2410
s = strong
Cm. - 1
Strontium nitrate
Sr(NOdz
45.
836
1378
1587
1790
2431
3170
3360
Positions and Intensities of Infrared Absorption Bands (Continued)
m = medium
Potassium phosphate, dibasic
KzHPOc
837
11.95 s
934
10.7 s
990
1 0 . 1 vs, vb
1110
9.0
w,sh
1350
7.4
m, sp
1835
5.45 m
2380
4.2
m
2860
3.5 m
68.
Potassium phosphate
monobasic*
KHzPOc
538
18 59 m
900
1 1 . 1 m, vb
1090
9.15 m , b
1300
7.7 m
1640
6 1
m, b
2320
4.3
m, b
1105
1410
3075
1
s. b
m
Arsenic trioxide
AS?Oa
1 2 . 4 5 vs
11.9
w, sh
9 6
vw, b
78. Antimon pentoxide
Sbr8r
685
1 4 . 6 v w , real?
740
13.5 s , v b
3225
3.1
w, b
69.
iii:
m, b
m, b
vw, b
m, vb
m ,vb
m. vb
Antimony trioxide
Sb2Oa
14.5 w
1 8 . 5 vs
1 0 . 5 vw, b
690
740
950
79.
Magnesium phosphate,
monobasic
Mg(H2POa)z
755
13.2
w. vb
943
10.6
1040
9.6
m,vb
1150
8.7 J
1235
8.1
w , sh
1640
6.1 m
13.3
11.75
9 8
7.9
6.3
4.4
3.85
Ammonium sulfite
(NHa)zSOa. H20
9 . 0 5 vs, b
7 . 0 8 v s , sp
3.25 s
80.
960
1135
1215
Sodium sulfite
Na2S03
10.4
rs,b
11.35 w
8 2
vw
V O L U M E 24, NO. 8, A U G U S T 1 9 5 2
1257
Table 11. Positions and Intensities of Infrared Absorption Bands (Continued)
vw
=
very x e a k
Cni.-'
xv = weak
I
Nicrons
81. Potassium sulfite
K?SOS.2H20
913
10.6 vs, vb
1100
9.1 vs, b
1175
8.5 s
6.07 v w
1645
5.3 vw.
1885
2.95 m
3390
82.
Calcium sulfite
CaSOs. 2HzO
:$; i:::
653
15.3
1100
1210
1625
3400
}
m = medium
86. Lithium sulfate*
LizSOa. H z 0
15.77 m
634
815
12.25 v w , real?
1020
9.8 v w
1110
9.0 T S
1170
8.55 m, sh
1
1380
7.25 Nujol
1625
6.15 m , sp
2.88 m
3470
+
87. Sodium sulfate
NazSOa
645
15 5
w
1110
9.0 vs
88. Potassium sulfate*
KzSOa
1110
9 0 vs
667
1010
1130
1630
1670
2200
3410
90,
660
825
1025
1135
3225
Calcium sulfate
CaSOa. 2Hz0
14.95 s
9.9 w, sh
8.85
6.13
5,95
4.55
2.93
vs, vb
s. sp
w
m. b
s, b
Manganese sulfate
MnSOd.2HpO
15.15 m
12.1 s
9.78 nr
8.8
3.1
vs, vb
s, b
91. Ferrous sulfate*
611
990
1090
1150
1625
3330
FeSOh. 7Hz0
16.37 s , v b
10.1 vw
9.2 vs, vb
8.7
m,sh
6.15 m
3.0 s , b
sh = shoulder
101.
Microns
-
93.
1080
1630
1650
3195
94.
Zirconium sulfate*
ZrSOa. 4Hz0
15 95 w
15.4 w
13.8 w
13 0 v w , sh
10 9 v n , sh
9 7 w, sp
9.25 vs, vb
6.12 m
6.05 m
3.13 s
Chromium potassium sulfate
Crz(SO4)d . KzSOa. 24Hz0
1090
9.2 vs
1660
6.05 w, b
2.97 m
3370
95. Ammonium bisulfate
NHaHSOa
855
11.7 m. b
1035
9.65 m, b
1180
8.5 m, b
1410
7.1
vw
3180
3.15 m
,
Ammonium sulfate
85.
(NHa)zSOa
15.5 w
645
9.05 vs. b
1105
1410
7.1 vs, sp
5 , 7 5 vw
1740
3.25\
3032
3.161 s * s p
3165
89.
very strong
-
b = broad
= KBr region (15-25p) examined
Cm. -1
627
650
720
770
920
1030
84. Zinc sulfite
ZnSOs.2HzO
11.7 s , vb
10.57 w
9.8 s
9.1 m
8.6 m
6.13 m
3.15
2.951
*
I
m, b
~ sh ,
vw,vb
83. Barium sul5te
BaSOa
638
15.7 m
917
10.9 vs. b
990
10.1 w
1070
9.35 m,vb
1200
8.35 m
1410
7.1 v w
YS =
92. Copper sulfate
cusoa
680
14.7 m
805
12.45 m
860
11.6 m
1020
9.8 w, sp
1090
9 . 2 vs, vb
1200
8.35 s
1600
6.25 w, sh
-3300
3.15 s , b
Cm. -1
9.1
8.3 vw
6.15 m,sp
2.94 s , s p
855
945
1020
1100
1160
1630
3170
3390
s = strong
96. Sodium bisulfate
NaHSOh
655
215.3 ni
12.95 vw
773
-
665
1000
1115
1645
2250
3200
3360
3450
Magnesium thiosulfate
MgSzOr .6Hz0
-1n.O
s
10.0 s
8.95 vs
6.08 m
4 . 4 5 > v. vb
3.13
2.981 s
2.9 )
102.
Barium thiosulfate
BaSzOs.U2O
m
s
m
vw
m
820
848
877
1005
1065
1160
1280
1325
1640
2600
2900
Potassium bisulfate
KHSOa
12.2 w , s h
11 8 s
11.4 s
9.95 5
9.37 S , SP
8.6
vs,b
7.78 s
7.55 w, s h
6.1 w
m. vb
3.85 v w
3.45 s , v b
2:: j>
98. Ammonium thiosulfate
(NHdzSzOa
953
10.5 s
1065
8.4
s
1390
t.18 s
1650
6.05 w
2960
3.4 s , vb
99. Sodium thiosulfate
Na&03.5H20
677
14.8 s
757
13.2 v w , sh
1000
10.0 vs
1125
8.9
8.6
1165
1630
G,l5 w
1660
6.03 m
) '"
2080
3390
2.95 vs
100. Potassium thiosulfate
KzSzOs. H20
658
15.2
676
14.8
10 03 s
995
1120
8 95 v s
1625
6 15 v w
3300
3 03 w
Cm. -1
Potassium selenate
KsSeOa
12.35 v w . s h
12.13 s , sp
11.67
11.42
11.15
9.22
9.0
8.75
7.28
5.73
4.18
89?
Sodium metabisulfite*
Na&Os
4.56
m
21.91
14..58
.:
I2
a31
m
18.81 m
1.5. 171
660
fifi7
973
1,j.n /
in.25
0.4.5
8..5
7.9
lofin
11x0
1265
112.
vs
v w , sh
Potassium metabisulfite
KZSZO5
RR2
1,5.l
rn
475
1 0 . 2 5 cs
iofin
4.ii
10x0
9 . 2 i ni
104.
1105
9 0.5
R. i
105.
fi?7
702
865
lOR0
1085
-1190
1280
14211
3260
ni
7's
8.0 r w , ~ h
Ammonium persulfate
(NHi)zSzOq
15.7
vw
14.23 s
12.5- w
11 ..?.a 7-w
-
4.45
4.23
8.4
7.8
7.0.5
s,sp
3.07
E
m,
s , 3p
I060
9 1?
1270
7 88
1100
7 7
3300
3 02 w
107.
720
788
112.5
1450
3330
r
Sodium selenite
NazSeOa
18.7
vs
12.7 s
8.4 w , h
6.9 Nuiol
?
3.0 w, b
+
-
109.
@
860
1235
1420
1640
2320
-3140
Ammonium selenate
(NH4)zSeOa
13.0 \
i:;i31
vs,vb
11.63,'
8.1 w
7.03 s
6.1 m
1.3 ni
3.18 v s
-
938
962
1610
3S40
3570
116.
vs
108. Copper selenite
CuSe08.2Hz0
714
14.0 v s
768
17.0
m.sh
807
12.4 r w , s h
918
10.9 m
1570
6.35 m
1650
6.05 w
4.4 vw, v b
2270
-3120
3.2 1
3450
2.9 1
770
114.
vs
w, sp
w,8p
Copper selenate
CuSeOa. 5Hz0
13.0 m, b
11.65 s
10.85 m
6.25 m , s p
3.1 \
2.951
113.
935
965
990
vw
vw
Sodium chlorate
NaClOa
10.7 s , s p
10.35:
10.1 ( vs
Potassium chlorate
KClOa
10.65 w
10.4
YS
t:;:5]
KzS201
14.1
770
858
922
1600
3220
3390
vw
m
vw
115. Barium chlorate
Ba(ClOa)n.H z O
SD
w,sh
v'
106. Potassium persulfate
710
1080
1110
1140
1375
1745
2390
vs
1's
I
Microns
875
857
103.
imp. = impurity
110. Sodium selenate
Na~Se04.10H~O
735
13.6 vw, sh
793
12.6 vs
838
11.95 vs
573
11.45 vs
I105
9 05 m
1125
8.9 m, s p
8.6 w
1165
1240
8.07 m
1390
7.2 s
1640
6.1
m
2350
4.25 s
3220
3.1 m
3500
2.85 s , s p
810
824
793
97.
sp = sharp
111.
117.5
1250
8.0
8.1
6.02
3.85
2.88
I
Rlicrons
-
vb = very broad
1060
1136
1420
3330
vs. v b
6.2 m,s p
2.83 s , s p
2.80 s , s p
Ammonium perchlorate
NHaClOa
9.45 v s
8.8 s , s h
7.05 s
3.0 s, sp
117. Sodium perchlorate
1100
1630
2030
3570
NaCIOI. HzO
0.1 vs, b
6.14 s , s p
4.93 vw
2.80 s , sp
118. Potassium perchlorate
KClOc
w
637
15.7
940
10.65 v w
1075
93 s
1140
8 . 7 5 s . SI1
1990
5,02 cw
119. Magnesium perchlorate
MgClOi
652
15.35 rn
10.58 w
943
10.4
w
962
9.45 vs
1060
8 . 85 \I
1130
6.13 s , sp
1625
4.8
P , vb
2100
2.83 s
3540
ANALYTICAL CHEMISTRY
1258
Table 11. Positions and Intensities of Infrared Absorption Bands (ConcEuded)
vw
=
very weak
K
= weak
m = medium
C m - 1 Microns
I
120. Sodium bromate
NaBrOz
807
1 2 . 4 vs
121.
Potassium bromate
KBrOa
12.65 vs
790
122.
765
797
1280
Silver bromate
AgBrOs
13.08 s
12.55 vs
7 . 2 5 Nujol
?
+
123.
Sodium iodate
NaIOs
;;; i;:?}
vs
800
m
12.5
124.
738
755
800
Potassium iodate
KIO?
13.55 vs
13.25 s
12.5 w
125. Calcium iodate
Ca(I0s)z. 6HzO
13.35 m
748
13.15 m
760
775
12.9 s
817
12.25 8
827
1 2 . 1 vw, sh
838
11.93 v w , s h
1610
6.20 w , s p
3350
3450
i::8}
126.
848
Potassium periodate
KIOa
1 1 . 8 vs
127. Ammonium metavanadate
NHdVOa
690
14.5 s, vb
843
11.85 s
888
11.25 s
935
10.7 s
1415
7.08 s , sp
3200
3.12 8 , sp
128.
693
828
910
935
957
3450
129.
74 5
843
865
935
1410
1650
2860
2990
3120
130.
680
820
855
890
915
1665
2125
3170
131.
858
935
Sodium metavanadate
NaVOa . 4 & 0
1 4 . 4 s, b
12.08 s
1 1 . 0 vw
10.7
10.45}
2.9
w, b
Ammonium chromate
(NHd)zCrO4
13.4 m
11.85 m, ah
11.55 vs, b
1 0 . 7 m. sh
7.1
8
6.05 m
3.5
m.sh
3.35 s
3.2
m,sh
s = strong
1
10.90
6.0
4.7
3.15
*
= very
= KBr
strong s h = shoulder b = broad
region (15-25p) examined
Cm.-1 Microns
Z
132. M a nesium chromate
MgErO4.7HzO
695
14.4
w, v b
765
1 3 . 1 w, b
855
11.7 m , s h
877
1 1 . 4 vs
1620
1650
::I%}
2270
4.4
m, b
3260
3 . 0 7 vs, b
133.
Barium chromate
BaCrOa
i i g ii:z5} vs b
930
3450
142.
1
135. Lead chromate
PbCrO4
825
855
vw. vb
885
11.3
::::1
vs.b
Potassium chromate
KzCrOh
11.65 w, sh
11.45 vs
10.7 s
=
very broad
820
855
900
1680
3280
143.
Copper dichromate
CuCrz01.2HzO
1 3 . 3 s , vb
10.65 s
6.15 m
2.9
s
Sodium molybdate
NazMoO,. 2 H ~ 0
12.2
vs
11.7 m
11.1 m , s p
5.95 w
3.05 s
Potassium molybdate
KzMoOa.5HzO
1 2 . 1 va
11.1 m
3.02 m
825
900
3310
144.
Ammonium heptamolybdate
(NHa)nMoiOzi.4HzO
663
1 5 . 1 vs
836
11.95 m
877
11.4
vs
913
10.95 w , s h
1420
7.05 s
1640
6.1
w
3080
3.25 s, b
sp = sharp
136.
745
950
1010
1300
1625
3460
3520
Aluminum chromate
Alr(CrO4)s
13.4 s , v b
10.5 s , b
9.9
s
7 . 7 vw
6.15 m
;:ii}
137. Ammonium dichromate
(NH4zCrzOi
730
1 3 . 7 vs
877
11.4 m
900
11.1 m
925
10.8 s , s h
950
10.55 s
1410
7.1
s,sp
2850
3.5
m, sh
3060
3170
::%}
145.
810
822
8.50
925
1670
3310
Sodium tungstate
NazW04.2 H z 0
12.35 w , s h
12.15)
11,751 vss
10.8 w
6.0 w
3.02 s
146. Potassium tungstate
KsWOc
750
13.3
vw
823
1 2 . 1 5 vs, b
925
10.8 w
1680
5.95 w
3170
3.15 m
3320
3.01 w,sh
147.
794
1640
3390
Calcium tungstate
Caw04
1 2 . 6 vs, vh
6.1 w
2.95 m
152. Sodium ferroc anide
NaaFe(CN)s. lOd0
1625
6.15 s , s p
2000
5.0
vs
2020
4.95 m, sh
153.
930
995
1630
1650
2015
3410
3510
Sodium dichromate
NalCrzOr .2Hz0
13.55 vs
12.8 m
11.25 8. sp
11.0 m , s p
9 . 0 7 vs
7.2
Nujol
1
8 , SP
2.85 8
;:A;}
+
139.
568
760
795
885
905
920
940
1305
Potassium dichromate*
KnCrzOi
17.61 w
13.15 vs
12.55 m
11.3 m, SP
11.05 m , s p
10.85 w , ~ h
10.65 vs, b
7 . 6 5 vw
148.
Sodium permanganate
NaMn04.3Hz0
840
1 1 . 9 vw, sh
896
11.15 vs
1625
6.15 s,sp
w,b
3510
2.85 s
$::: ::e}
149.
Potassium permanganate
KMnOd
845
11.85 w
900
11.1 vs
1725
5.8 w
150.
840
905
1625
3470
Calcium permanganate
Ca(Mn03z.4HzO
11.9
m
11.05 vs, b
6.15 8 , s p
2 . 8 8 vs
Potassium ferrocyanide
&Fe (CN)8.3H20
10.75 vw
10.05 vw
6.13 8 , sp
6.07 m
4 . 9 6 vs
;:%}
154.
Calcium ferrocyanide
CazFe(CN)n. 12Hz0
1615
6 18 m
2015
4 . 9 6 vs, sp
3390
2 . 9 5 vs, b
155. Potassium ferricyanide
KsFe(CN)e
2100
4.77 s
847
1333
1430
1575
1645
2665
2780
3450
Sodium cobaltinitrite
NaaCo(N0l)s
11.8 s , s p
7.5
vs
7.0
vs
6.35 m
6.07 w
3 . 7 5 vw,s p
3.6
vw, sp
2.9
m
157.
Ammonium hexanitratocerate
(NHdzCe(N0dn
745
13 42 8 , sp
803
12 45 m, sh
807
12.4 8 , sp
815
12 25 vw
1030
9 7 s, s p
1050
9 5
vw
1260
7 95 vs
1325
7 55 w
1420
7 05 s
1530
6 6
vs, b
3210
3 11 s, b
158.
138.
imp. = impurity
Cm.-1 Microns
I
151. Barium permanganate
Ba(Mn0a)t
840
11.9 m , s p
877
11.4 s
913
10.95 s
935
10.7 m
156.
vs, b
m,sh
s,sp
m, b
750
940
1625
3450
10.75 s , s h
2.9
w
134. Zinc chromate
ZnCr04.7HzO
720
13.9 m
795
12.55 s
875
11.4
940
10.65
1050
9.5
1090
9,l5 s,b
1183
8.45 m
1620
6 . 1 5 vw
1820
5.5
vw, b
2700
3.7
w, b
3450
2.9
s,b
vb
Cm.-1 Microns
I
140. Calcium dichromate
CaCrzO7.3HzO
725
1 3 . 8 vu.
830
12.05 m
900
11.1 m
940
10.65 s
1625
6.15 m
3450
2.9 s
141.
Sodium chromate
NaKrOd
14.7 m
i?::
11.2
vs
1410
1780
2000
2860
3070
3150
Ammonium chloride*
NHiCl
7.1
8 , sp
5.75 w,b
5.0
vw
3.5
m
::?!}
159. Barium chloride
BaClz.2HzO
700
1 4 . 3 vs, vb
1615
6.18 8 , sp
1645
6.07 8,sp
3370
2 . 9 7 vs
2918
2861
1458
1378
720
160. Nujol
3.427 s
3.495 a
6.859 m
7.257 m
13.89 w
V O L U M E 2 4 , NO. 8, A U G U S T 1 9 5 2
1259
one of the salt plates with a very thin layer of solid paraffin to
The purities of the samples are indicated in the legends for the
hold the particles in place (6, 7 ) . The fine powder may be precurves.
pared by grinding, by evaporation of a suitable solvent (6, 7 ) , or
Some idiosyncrasies of the curves warrant mention. Many of
by sedimentation ( 5 ) . Vacuum evaporation which has been
them show weak remnants of the carbon dioxide bands near 4.3
used for preparing films of ammonium halides ( I I ) , may be useful
and 14.8 microns. The latter always appears as a sharp upward
for other relatively volatile inorganic materials.
pip. Many of the curves exhibit a drop in transmission near
Spectroscopic Procedures. 8 1 1 samples were examined from
15 microns and then a small increase beginning at 15.5 microns.
2 to 16 microns with a Baird XIodel A infrared spectrophotometer.
The initial decrease is due to the absorption by the sodium chloride
Wave lengths are accurate to about zt0.03 micron, although for
plates, which was not compensated in the reference beam. The
broad bands the error of judging the center may exceed this. It
reason for the later increase is not known, but it is not real. It
was sometimes found that duplicate spectra for the same comhas the effect of suggesting an incorrect position for bands near
pound differed by more than this
amount. Some oossible reasons
are mentioned below.
Table 111. Infrared Bands of Various Nitrates (Cm.Representative ex a m p 1 es of
Intensity
m, s p a
w
m, sp
w
VS
S
S
VS
vw
several ions were examined in
..
, .
836
..
1358
..
..
1790
2428
the potassium bromide region
824
1767
..
1380
, .
..
733
803
835
1318
..
with a Perkin-Elmer 12B spec, .
..
820
1044
(1359)
( 1430)
(lii0,
737
..
815
..
1387
1795
1441
..
2iio
trometer. Likewise, a series of
729
..
817
..
1352
1418
1774
(2410)
ten nitrates was examined in the
(1785)
..
835
..
1361
, . . .
(1640)
i6ij
..
(807)
836
.,
1372
..
rock salt region with this same
836
..
1378
....
1587
1790
2431
726
807
836
..
1373
, .
..
instrument in order to fix the
Bands >3000 cm.-L are omitted.
wave lengths of absorption more
( ) Baird values, less accurate.
accurately.
a w, ni, s = weak, medium, strong. g p = sharp.
v = very.
No attempt was made to put
the spectra on a quantitative
basis.
RESULTS
16 microns. For example, in ferrous sulfate heptahydrate
The spectra are presented a t the end of this paper. Table I
( S o . 91) the curve indicates a band a t 650 cm.-l (15.5 microns),
lists the compounds examined and gives the numbers of the corbut actually it is a t 611 ern.-' (16.5 microns).
responding spectral curves. Table I1 summarizes the positions
DISCUSSION OF RESULTS
of the bands in wave numbers and in microns, and gives estimated
peak intensities. If more precise wave numbers have been
The spectra range in quality from surprisingly good ones, with
determined with the Perkin Elmer spectrometer, they are used.
sharp, intense bands (see curves for barium thiocyanate dihyAsterisks indicate those compounds examined in the potassium
drate, No. 28; strontium nitrate, No. 44; and ammonium
bromide region.
hexanitratocerate, No. 157,) to very poorly defined ones such as
The spectra themselves are shown in graphical form. Nujol
those for potassium silicate, S o . 32; monobasic magnesium
bands are marked with asterisks; portions of curves run in fluorophosphate, No. 69; and monobasic potassium orthoarsenate,
lube are indicated by an F. The spectra of Nujol and fluorolube
KO.75. I t seems to be characteristic of the phosphates, and
are included for comparison (No. 160). I n a few cases the ponder
especially of their monobasic and dibasic modifications, to have
was used without a mulling agent; these are indicated by P.
ill-defined spectra. The reason for this is not clear, but it may
be due to lack of a single, well-ordered crystal
c rn-1
structure.
Effect of Varying Positive Ion. One of the purposes of this study was to ascertain whether the
various ions have useful characteristic frequencies.
It was therefore of interest to know the effect of
altering the positive ion. The spectra of ten SUIfates are shown in Figure 1 in the form of a line
graph. I t is seen that two characteristic frequencies occur, one a t 610 to 680 em.-' ( m ) and
the other a t 1080 to 1130 cm.-l (s). There is
enough variation between the individual sulfates
so that it is often possible to distinguish between
them from the exact positions of the bands. Table
I11 presents similar data for ten nitrates. Again
there are characteristic frequencies, a t 815 t o
840 cm.-' (m) and 1350 to 1380 (vs). The authors
I
have been unable to find any orderly relation between the positions of these nitrate bands and a
MnSO4.2W
property of the positive ion, such as its charge or
I
I
mass. This is not surprising, for there are a t least
ZrSO4.4W
three reasons why a frequency may shift slightly as
I
I1 .
I
C r S 04' K2S 04
the kind of positive ion is changed.
24 W
Figure 1.
Comparison of Infrared Spectra of Ten Sulfates
W. Water
vh. Very broad
s h . Shoulder
The different charges and radii of the various
positive ions produce different electrical fields in
the various salts. These doubtless affect the vibrational frequencies of the negative ions.
(Continued on page 1298)
ANALYTICAL CHEMISTRY
1260
IW
/4n
I
I
I
10
A~
Z;\ $U:
z
i
40
f~
20
,
~
~
1
J
~I
2
500)
4
8
7
low
Urn
2SW
5
6
I
WAVE LENGlH IN MICRONS
WAVE NUMBER5 IN CM'
,5WI,W
?OW
I200
IIW
~
\
~
Sodium metaborste,
NaBOz
;I
C.P.
~
I
0
I
,
F
= bo
W
I
10
liW
Iwo
I1
12
I
I1
1s
I4
' 0
WAVE NUMBERS IN CMI
9w
aw
b2S
700
Magnesium metaborate,
Mg(BOz)z.SH:O
C.P.
2
1
4
5
b
7
WAVE LENGTH IN MICRONS
WAVE NUMBERS IN CM
5wo
100)
Urn
2100
lwa
Ism
,104
I
I1W
9
I100
IO
IIW
Iwo
12
I1
WAVE LENGTH IN MICRONS
11
9w
I4
WAVE NUMBERS IN CM'
I00
IS
7w
I6
b2S
100
lM
Lead metaborate,
Pb(BOdn.Hz0
IO
IO
560
bO
C.P
3
z
g*
40
z
20
20
0
I
2
4
5
6
7
WAVE LENGTH IH MICRONS
8
IO
P
I,
I1
I1
WAVE LENGTH IN MICRONS
I4
IS
I6
0
Sodium tetraborate,
Na2BO. 10Hz0
C.P.
WAVE LENGTH IN MICRONS
WAVE LENGTH IN MICRONS
WAVE NUMIRS IN C H
500)
(ooo
100)
2Mo
low
,5Wl,W
1100
IIW
llW
Iwa
9W
WAVE NUMBERS IN CM1
ud
IM
7w
625
Potassium tetraborate
KgBdO?.5HzO
IO
c
iz *
z
e
1"
:
20
0
WAVE LENGTH IH MICRONS
WAVE LENGlH
IH
MlCRMlS
P.
V O L U M E 2 4 , NO. 8, A U G U S T 1 9 5 2
1261
IW
80
1
I
.
E
i
ZbQ
I
z
I!
r
"
10
1
1
,
C.P.
M)
*
Y
~
v
20
0'
I
IW.
4
5
8
7
b
\l/*la/ !1
s
I
11
IO
0
1
10
II
0
11
I1
I4
I.
I5
IO
V "
l
*
j
I
V
ilo
1
'1'"Sodium perborate,
60/
r
I
?;aBOa.lHdI
Y
E'O
'
I
'I
10
s5
Manganese tptraborate,
MuB4&.8HzO
6'*
j
II
L'
f, '0.
1
I
I
\AIL
I
I
I
~
~
I
1
6
7
1
I
V
(0
*
I
~
:L/;
I
C.P.
lh/--,
I
~
10
I
I
I
I
l
l
I1
I
I1
I1
10
0
I5
I4
Ib
Boric acid, HiBO
02.
SVX
100.
Y
IO
1VX
4oW
.
<
/
ZSW
1VX
r
F
!
z
p7f
'
IIW l u x )
.
Q'
1
100.'
1
/
I
1
4
5
b
-#-10.
H
F
fa-
zi
615
loo
7m
10)
-
'm
*
I
10
I
I
7
I5W
J
I
lux)
1lW
9
1100
1100
10
11
IVX
I
I1
I4
700
iw
(w
I5
Ib
615
1'0
i
V
I
AR
u
64
40
lo
8
0
9
0
I
Lithium carbonate,
LizCOa
IO
I
~
1
Pure
M
I \,
i *-
Boron nitride, B N
9
1
1
~
9w
*
I
10
loo0
I
~
Y
liW
uI
'Ob
Y
I
IlW
/
c
L
c
1100
I1
I1
I
IS
Ib
ANALYTICAL CHEMISTRY
1262
WAYL NUM?ERS IN C M '
5ccO
wO
3w0
15W
iico
1 5 w 1 4 c a 1100
lw(.
WAVE hLM5ERS Ih C U I
iom
)loo
FCO
100
6CC
bli
Sodium carbonate,
NazCOi
AR
Potassium carbonate,
KnCOi
AR
Magnesium carbonate,
basic, 3MgC.01Mg(OH)n.aHnO
Unk
Calcium carbonate,
CaCOa
AR
5wO
u40
1wO
2m
ISWilW
1004
I700
IIW
ll00
I
IW
IOW
9w
IW
IM
7
80
!
J
I
b15
15Im Barium carbonate.
3
r
BaCO:
-80
AR
"
5.f
Y
I
~
1"
Y
10
--~
-
*
1-1
I
!
10
41
b
1
5
L
WAVE LENGTH IN MICRONS
1
I
V
0
I
I 1
I1
WAVE LENGTH IN W C R M I S
10
I5
b0
V O L U M E 2 4 , NO. 8, A U G U S T 1 9 5 2
I,263
WAVE NUMlfRS IN u ( l
WAVE NUMBERS IN C M '
5
io0
Cobaltous carbonate,
COCOl
W
Unk.
m
1
1
5
b
I
WAVE LENGW IN MICRONS
I
11
I1
I1
WAVf LfNOTH IN MICRONS
14
16
0
lb
Lead carbonate, PbCOj
Unk.
Ammonium bicarbonate
NHiHCOa
Sodium bicarbonate,
NaHCOa
C.P.
Potassium bicarbonate,
KHCOI
C.P.
ANALYTICAL CHEMISTRY
1264
IW
I
I
i
Sodium cyanide,
NaCN
80
I
'Na,CO.
-
k.
NaaCO3
impuritg
W
I
40
P
20
20
I
0
I
0
Potassium
cyanide
KCN
IlHCOa and
K:COa
impurities
Potassium
cyanate,
KOCN
Considerable
KHCO
impurity
Silver cyanate,
AgOCN
"Higheat
purity '
I
IW1
\
IO
s
I
mPY- I,/
fM
'
Ammonium thiocyanate,
2 5 1 m
1
"
AR
'D
F
c
E"
10
E
1
10
1
10
I
0
1
1
'
8
WAVE LENGTH IN' MICRONS
e
10
I
II
I1
WAVE LENGTH IN MICRONS
14
0
5
NHaSCN
80
\
I
I
2
1
I
-7
Ib
V O L U M E 24, NO. 8, A U G U S T 1 9 5 2
1265
Sodium thiocyanate,
SaECS
Potassium thiocyanate
KBCS
AR
WAVE NUMBERS IN C M '
XCC
IW
Urn
3wO
1SW
3000
ISW
I4W
12w
IIW
I W
Iwo
9w
WAVE NUMIIERS IN CM
8W
b25
IW
100
IO
(0
M
(0
Barium t h ~ o c y a n a t e
Ba(SCX):.2HzO
C.P.
i
f
e
4
5"
$
10
20
0
0
3
1
sox 4ccc
1
3mo
25w
5
h
7
WAVE UN6TH IN MICRONS
WAVE NUMBERS IN CM
2000
I5W
1
l4W
l3W
V
17W
IO
W
IWO
I!
Vw
I2
I3
WAVf LENGTH IN MICRONS
I4
WAVE NUMOERS IN CM1
8W
lb
bl5
lW
703
lW
1-
Mercuric thiocyanate,
Hg(SCS)*
m
(0
Pure
(0
4
I"
Y
20
10
0
0
3
2
SWO
4
IWO
4wO
ISW
5
6
7
WAVE ttNGrn IN M~CRONS
WAVE NUUBERS IN C M '
lD00
1503
I+W
V
IIW
I1W
I
0
w
lax,
9w
It
I3
W A S Wlli IN MICRONS
15
I4
WAVE NUMBERS IN C M '
SOD
7w
Ih
hl5
-01
lop
Lead thiocyanate
Pb(SCN)*
m
IO
3
C.P.
kt4
n
<
rm
4Q
v
20
0
1
I
5
L
7
WAVE LENGTH IN MICRONS
V
IO
I1
I1
11
WAVE LEN6TH IN MICRONS
Ib
IS
Ib
0
ANALYTICAL CHEMISTRY
1266
Sodium metssilicate,
NarSiOr5HaO
O.P.
Potassium nietrtsilicate,
KrSiOi
O.P.
Xm
IW
Io.
1800
u*yI
1100
I
1
100
Irn
110)
Ilm
la4
no
rr-"---/
*
J
W
7
8s "
Iyo
lOm
1W
800
(11
Sodium ~ i l i r o f l ~ ~ o r i d ~ ,
33
\
SazSiFe
w
a.p.
?-
I
I'
1
L
*
W
1
44
20
20
~
0
0
3
I
I
1
b
WAVE NUMBERS IN
8
7
0
I1
CM
I
ll
I+
I&
Ib
WAVE NUMBERS IN CMI
Silica gel,
SiOmHrO
WAVE LM6W IN MICRONS
WAVE U N 6 W IN MICRONS
5
IW
Sodirim nitrite, NaNOi
H
44
10
0
2
I
I
5
WAVE
b
LWOM IN HICRM
7
I
*
0
II
WAbl IuN6W IN I MCRONS
3
4
It
4
b
C.P.
V O L U M E 24, NO. 8, A U G U S T 1 9 5 2
1267
Potassium nitrite, KXO,
C.P.
tm
'
I
-.
MI
3
f
1I
*
w
C.P.
L
Y
I
*
~
fi
I
1
2
\
Y
/
I
20
37IW Mver nitrite, AgKOz
/
1
I
4
la
20
0
e
5
6
7
WAVE LEWTH IN UlCRONS
IO
I
1
2
WAVE LENGTH IN WCRONS
14
I5
WAVE NUMBERS IN CM I
WAVI NUMBERS IN C U I
Ib
5
Barium nitrite,
Ba(N0:hHsO
80
C.P.
Y
a
20
2
1
5
6
WAVE LLNGTP IH H U M S
7
I
e
0
IO
II
I2
WAVE ENOW IN
I1
mcRoNs
I4
I5
Ib
5
im
Animonium nitrate,
NHaKOs
W
C.P
Y
20
2
I
I
5
WAVE UNOIH
b
m
7
MICROHS
WAVE NUMBERS IN C U
I
IO
II
12
I>
WAVE LENOM IH MICRONS
I4
Ib
*
WAVE HUMBEIS IH C W
Sodium nitrate, KaNOa
AR
a
WAVf YHCM IN MICRONS
ANALYTICAL CHEMISTRY
1268
5wO
W
UDO
105)
2SW
2mO
z
ll00
IXd
rn
im
,
b25
700,
,
loo
l P \ w d '4l Io
//
1'
60
IlW
llm
1100 l4M
I
z
A 11
I
1
bo/
;
g
S
Potassium nitrate,
KSOa
M
1
'
401
*
e
10
I
I
10
I
10
0
1
1
I
5
b
7
I
0
I
1
1
I
IS
Ib
*
Silver nitrate, AgSCs
C.P.
Calcium nitrate.
Ca(Pi0dp
C.P
Strontium nitrate,
Sr(XOd3
Unk.
WAVE WUMlERS
N CM
5
100
(D
10
10
1
1
4
5
b
7
WAVE LENbTH H MICRON5
I
10
It
I1
I1
WAVE LEN6lV IH MICRMIS
16
IC
1b
*
Barium nitrate, B~.:(?jod?
A It
V O L U M E 24, NO. 8, A U G U S T 1 9 5 2
1269
Cuprio nitrate,
Cu(XOi):.3H:O
C.P.
Cobaltous nitrate,
CO(;203)
2.6 €I20
AR
Lead nitrate, Pb(XO3)
AR
100.
IW
80
~
z
2
bo-
i9
20
0
2
no
~
i'
3-
\r'
AR
I
/
P
Ferric nitrate,
Fe(S03)3.9H20
*7
49
"
- '
\ /
p
z
i
t
4
,
4a
~
"
'
W A d LENGTH IH' MICRONS
20
a
I
V
0
I
2
I3
WAVE LENGTH IN MURCUS
0
Ik
I5
Ib
Bismuth subnitrate.
BiOSO3.HnO
Unk.
ANALYTICAL CHEMISTRY
1270
IW
80
5
EM
I
'0
/
I
F
\J
1
\
"
I
s
f
Y
I
I
\
!
I
1
1
5 M Mo(
I w - ' I (
" '
3oW
, 2'W'
'
1
I
v
i
v
t
I
D
*
3- ji !
L:j
lol
0
~
2
I
swo k4f8
IW
80
'
!'
5
10
V
*
0
2
3
I
,
0
I4
IS
Ib
i 52lw
;
2100
zoo0
lua
Ism
I2W
IlW
IlW
IO
Imo
11
c. P
I
I
40
I20
i
I1
I2
/--..,
b25
700
I
I
153r
I
J
i
I
i?
ba
I
I
I
I
8
.
C.P.
4a
I
!
Magnesium phosphate,
tribasic,
Mga(POdyAHz0
I8O
,
I
~1
t
5
b
WAVE LEN6TH IN MlCRMiS
' 0
15
I*
aw
(00
I
-$
!
I
e
8
Potassium phosphate.
tribasic, &PO4
10
I
IC/
I
7
b
I; I
P
1
I
I
:i
I I
I
I2
I1
WAVE LENGTH IN WCROHS
I
I
f
Z"
l
\\
j
'A
P
g,
g
I1
l
I
b-,*
?I
I
\
:1*
1m
" .
4a
I
!
*
/I
a-
1
I'\
W
\ I
I
i
\ I
I
80
b4
20
I
I
b
7
W A M L W l H IN MICRONS
I
AR
/
( 1
1
10
0~
2
Eodium phosphate,
tribasic, NalP04.12H;O
51:
I
IO
0
0
I1
I2
I3
WAVE LENOW IN MICRONS
Ib
Calcium phosphate,
tribasic, Cas(PO4)r
r.e
Manganese phosphate,
tribasic,
Mni(POdp.7H10
C.P.
V O L U M E 24, NO. 8, A U G U S T 1 9 5 2
Imp
1271
WAVf NUMBERS IN CM1
WAVE NUMltRS IN C M '
m
tmo
2100
Ima
IW
I-
IZW
IIW
I
IN
tW
imp
iim
I
IW
/
ir\ 7
1
.
m
.,
,
,
qoo
LIS
5
I
I
!
I
i
i
~
l
Nickel (ow) phosphate,
tribasic,
Nia(POdz.7 H?O
-
1
/ *
,
I
I
*
/,
1
I
\ \,
L,
I
I
I
,
I
7
I
I
I
I
I
;
I
I
0
Copper(ic) phosphate,
tribasic,
Cut(POa)z.3H10
C P
5wO
ION
IWP
25W
WAYZ NUMBfRS
ZOW
H CM
15w
Iuc
Lm,
1100
lIW
Iwo
WAVE NUMBERS IN C M '
9w
100
IN
b15
phosphate, tribasio,
58Iw Lead
PbdPOdz
IO
I
C.P.
I?
I
I
~
'
i*
10
I
1
.
I
5
b
7
WAVE LENGTH IN MICRONS
I
V
0
I
12
I1
WAVf LENGTH IN HhROlll
0
I4
I5
Ib
WAVE NUMBERS IN CM
5
iw
(0
Chromic phosphate,
tribasic,
CrPOc.Hn0
P.P.
M
40
20
5
b
I
WAVf LfNGTH IN UICROM
I
V
IO
I1
I1
I>
WAVf LENGTH IN MKRONS
0
I4
I6
Ammonium phosphate,
dibaaio,
(NHOrHPOt
C.P
A N A L Y T I C A L CHEMISTRY
1272
WAW W
W
S IN CU-
l5a
IUD
I1rn
I200
llrn
WAVE NUMDERS IN C U I
700
100
Im,
b25
100
100
S
80
Sodium phosphate, dibasic, NaSHPO 1.12 H20
C.P.
U
E
I"
4
P
n
10
I
1
I
4
I
I
5
b
1
WAVr W T H IN UCRONS
I
8
IW
*
I
I
10
I1
I
1
I2
I1
WAVr LW6W IN MICRONS
I
I
I4
I5
Ib
Potassium phosphate,
dibasic, K ~ I I P C I
(0
C.P.
E M
f
o4
F
20
0
WAYS W T H IN MKRONS
WAVE ENSW IN UCRCUS
llagnesium phosphate,
dibasic, MgHPOa.3HzO
C.P
w urn
Irn
1m
2x0
WAYS NUMBERS IN CU I
WAVE NUMBERS IN C U I
2wo
5
ID3
10
Calcium phosphate,
dibasic. CaHP04.2H20
m
C.P
jM
f
Lo
5"
4
10
20
P
0
2
5
6
I
WAVE UNSW IN UKROM
1
8
*
IO
0
II
12
I1
WAVE LENGTH IN MICRONS
I4
I5
Ib
WAVE NUMllRS IN C U I
Barium phosphate.
dibasic, BaHPOi
C.P.
1
a
4
5
b
7
WAVr LBTW N W W
8
*
IO
I1
I1
t i
WAVE LWSM IN MICRONS
I4
I5
Ib
V O L U M E 2 4 , N O . 8, A U G U S T 1 9 5 2
1273
IW
phosihate, mono67lW Sodium
basic, KaH1POd.HsO
~
IO
ao
kb3
n
5
F
lJ
~-
5 a8
t
I
F
v
I
20
.
I
0
2
I
In
-v'd
20
I
L
7
1
1
I
9
I
I
*
I
lW
-
68~
.-
\J
*
I
0
I
P
2
5"
1
i0
I
IO
20
a
1
I
5
\
ia
w
I
IW
z
C.P
1
I
1
I
Potassium phobphate,
monobasic KHlPOl
C P
IbO
i*)
10
1
I
0
2
3
4
I
b
1
WAVE UNOTH IN *UCRON5
8
v
0
It
2
3
WAVE UNSTH IN MICROM
0
I4
16
Ib
.\Iagnesium phosphate
monohaeic, 3Ig(HzPO&
cC . P.
P.
I
0
2
I
4
6
b
7
WAVI W ? H IN MICRONS
8
ID
I1
I2
I3
W A X M O T H W MICRONS
I4
IS
Ib
Calcium phosphate, monobasic, C a ( H ? P 0 3 ~ . H r O
.\ R
ANALYTICAL CHEMISTRY
1274
Sodium rnetaaraenite,
YaAsOe
AR
I
I
IWW(
I
I
1
72O0
Ii
Calciuni orthoarhenate,
tribasic, Cas(AsOd2
to
C.P.
M
4a
l,
\
/
f/
XI
0
3
1
4
5
b
7
WAVf LfNGTH IN MICRONS
I
I
ID
12
I1
WAVE LLNGTH IN MICRONS
I
IS
I4
Ib
Fodiuni orthoarsenate. dihaiic, Na:HAsO~.iH,O
Unk.
Lead orthoaraenato,
dibasic. P ~ H A s O I
C.P.
WAVE NUMPfRS IN CM
X48
1000
*Dp
2100
IWO
Sm
110)
Ilm
,100
llm
Imp
9m
W A M NUHIILRS IN C H I
UD
7m
bZS
Im
P o t a w u r n orthoarsenate,
inonohasic, KH14a04
iR
M
4a
m
0
2
3
4
5
6
7
WAVE LENGTH IN MICRONS
8
10
II
I2
I3
WAVE LfN6lH IN HKRONS
I4
I6
Ib
VOLUME
24,
NO. 8, A U G U S T 1 9 5 2
1275
Arsenic trioxide, .-\sr03
Vnk.
Yodirirn
1276
ANALYTICAL CHEMISTRY
Potassium sulfite.
K?S0!.2H?0
r
I,
Calcium sulfite,
CaSOi.2H20
C.P.
Barium sulfite, BaSOi
C.P.
Zinc sulfite, ZnSOa.2HnO
C.P
Ammonium sulfate,
(NHWOd
Unk.
1277
Sodiuiii sulfate, Xa?SOd
AR
Potawlurn sulfate, lid304
AR
Calcium sulfate
CnS04.2H20
AR
aiilfare,
JInSOc2HzO
XIangnn-e
C.P.
ANALYTICAL CHEMISTRY
1278
Ziroonium sulfate,
ZrEOi,4H?O
i
I
BO
C.P.
~
d
,
,
I
I
oi
*
I
~
I
1
1
rJ
I 20
I
j
~
6
7
I
9
IO
j
I
I
I,
12
~
5
,
I
~
i
0
13
k
15
Ib
fii
!
IO
g i
5
bo;
*
\
10
z l
20-
ol
,I
I
1
*
I
I
'
i
i
:
1
bo
i
; . j ~I
!
I
I
__r
~
f~
5
J
110
I
I
5
WAM
tEwm
b
7
IN MICRONS
:
j"
1
i
0
Unk.
i
,
"
0
_ ,
V
Chroiniu~npotassium
ralfare, CI.E(SOI)J.lirR0~.24H:O
I1
I
,I
WAVE LENGTH UI UICRONS
IC
I
I
I
I,
I5
1
10
I6
Ammonium bisulfate,
NH4HSOl
C.P
V O L U M E 2 4 , NO. 8, A U G U S T 1 9 5 2
1279
Sodium biaulfate, XaHSOI
AK
Potassium bierilfate.
KHSOI
AR
Aiiiruoniurii thiosrilfate
( N€i,)..S2OI
C.P
Sodium thiobulfatr,
xa:S*03.5H?o
.IR
Potassium thioniilfntr,
KnSrOa.Hr0
C.P
ANALYTICAL CHEMISTRY
1280
I1100
IHD
31100
k1100
IW
WAVE NUMBERS IN CM
2Wa
IHDiHiO
,IS0
l1W
two
ilW
PW
W A M NUMBERS IN CM
BOO
700
b2S
IW
I
I
I
Magnesium thiosulfate,
hlgS20a.6H10
C.P.
Barium thiosrilfatr,
Be&Oa.H>O
C.P
Sodium ~netahisrilfite,
Wa?PtOs
Potassium nietittiisuifite,
Ii2SnOr
AR
IW,
Arnmoniuni persillfate.
(NHI)?S~O~
I
-
IO
4 1
.IR
1~
!bo7A
5
E
10
V
20
+i
I
,
* i
I
~
\
m
I
I
4
1
'il
,
5
b
1
8
j
P
O
0
II
I1
I
I4
I5
Ib
V O L U M E 24, NO. 8, A U G U S T 1 9 5 2
1281
Potassium persulfata,
KnStOs
C.P.
Sodiiini selenite, Pl'alSeOd
Pt i y e
IW
i
I
Y
A
5 M
I
40
Vnk.
I
I
~
I
1
20.
,
\
,I
4
I
20
\/
I
i
I
I
0
I
a
\
I
~
$
(0
\
t
\ /
z
5
selenite,
'I 08ImCopper
CuSeOL2HZ0
I
Y *? A
0
1
I
5
b
7
8
V
0
II
I2
I3
I4
IS
I6
Sodium selenate,
SazSe04.10H~O
C.P.
1282
ANALYTICAL CHEMISTRY
rKa urn
ma
WAM NUHBERS IN CM'
WAVE NUUlKRS IN C M '
1XD
mo
b%
100
,Cd
80
Potassium Belenate,
KzSeOi
W
C.P.
60
4
20
10
0
1
1
4
5
b
7
W A M LENCTH W MICRONS
8
IO
I1
I1
I3
WAM LENSTH IN MICRONS
I4
I5
Ib
0
Copper selenate,
CuSeOc5HzO
C.P.
Sodiuiii chlorate, liaCl01
AR
Potassium chlorate,
KClOa
AR
Barium chlorate.
Ba(C10a)z.HaO
C.P.
V O L U M E 24, NO. 8, A U G U S T 1 9 5 2
1283
WAVE N V H l E R S IN C U '
W A S NUMBERS IN C M I
5
IW
80
L.P.
M
4c
20
0
I
3
2
5mo
IW
ImO
UC4
I=
1
$10
8
L
11m
1100
Iom
I2
I3
W A M LLHSTH IN MICRONS
m
10)
sw
8W
I4
16
I6
I
&
11
11 ;ir
2
lrn
14w
II
IO
\n,.L'-\,
*
f""
1
',ii
s$ *
I
7.
lrm
2mO
1
p?,
IO
5
6
WAVE LENOTH IN MICRONS
I
I
I
I
LJ
x
10
t
0
ym
1w-
urn
3om
250)
2om
?
1
150)
,
14w
I
13W
l
l
la
I
,
l
l
IlW
ImO
> ! .I
80
:/
,
, ,
j
I
7w
d
)IS
i IS'*
I
80
AR
!
5
b0
n
I #
2Z W
i
I
Y
'
I
0
2
\,
I
I
3
S
7
b
I
0
9
IW
~
!
P
r rL
0
I2
I1
87 '
ZW
2
1
10
I
.
I
nf
V
/
I\ i
11
1
\L
i
1
I
I
I
2
3
4
S
b
7
9
IS
1
r'
1[
I
1
/
Mgd104
11 1191
10
I
,
h
~
I1
I
1
I
I
0
Ib
-lW
I
I
,
/*
I - '
I
10
I
02*+-
I
0
I4
I
/?\
I
d*
02I+!
11
I
10'
!
I
-
1
1
I
;
l
1
?r
,
IO
bo
I
z
2
I3
I
lo
I+
IS
Ib
ANALYTICAL CHEMISTRY
Potassium bromate,
KBrOa
hR
Silver bromate, AgBrOi
C.P.
Sodium iodate, KaIOz
C.P.
I
10
I9
0
0
I
I
4
6
b
I
7
0
I1
1
I
I,
IS
Ib
Potasaium iodate. K I O i
Unk.
Calcium iodate,
CaIOa.BHz0
O.P.
V O L U M E 2 4 , NO. 8, A U G U S T 1 9 5 2
1285
Potassium periodate,
KIO4
C.P.
.4mmonium metnvana.
date, NHcVO:
c. P
Sodiurn rnetavunadate.
SnVOz.IHr0
Sodium chromate.
KaL'rO4
ANALYTICAL CHEMISTRY
1286
ym
urn
3m0
Ism
WAVf NUMBERS
ZmO
M CM'
IUD
,100
1100
Im
I200
1100
I
wo
ImO
WAVE NUMBERS IN
800
\
'rlV$
-I
!5 ** z
1m
b2S
IW
I
IO
Potassium chroinate,
KnCrO4
I
+
~
rA
;
\\ P,
I
*
I
W
i 9,'
I
I
20
I
*
0
I
CM'
I
3
I
4
5
b
7
8
I
IO
I
//J
O
I
10
W'
,I
I1
I
0
I
I4
I5
I
1
Ib
l l a g n e j i u n i chroniate,
f iiii
i
I\
I
MgCrO~.iH~O
10
C.P.
Barium ciironiate, BaCrOa
C.P.
Zinc rhromate.
ZnCr04.7IipO
C.P.
WAM NUMBERS IN C M '
pm
WAVf NUHIERS IN
8W
CMl
1m
V O L U M E 24, NO. 8, A U G U S T 1 9 5 2
1287
136
Aluminiini chromate,
Alz(CrO4)i
M
I
I
C.P.
1
1
I
S
-/I
,
I
I
I
oI
,'
3
,
m>YE
Wr(0
im
1
0
8
5
1
7
WAVE W T H IN MICRONS
nm
IUD
t
I,
lua
Ilm
110
IlW
10
I
!/
lmo
em
Ho
625
7m
I 37'
l
'V
$
f
j
F
I
~~
~
I
1
10
I
.
0
3
8
-
I
,
0
.
2
I1
I1
I3
WAVE LENGTH m WCROHS
I
40
m
b
Sodium dichroinate,
NatCrtO; .2€ 1 2 0
I38
W
C.P
-c
I
Y
IS
I4
\
I
1-
/
rl
i i'L
d
t
44
m
IV
I
,
I
0
5
b
7
WAVE W T H IN MICRONS
mnm
uyx)uDo
IO
\
20
I *
7
7T
1 -
1I
I
!\!
!/[
- I
!/
\1 I
,VI
0
5
b
7
WAVE LINGTH IN MKlOHS
IO
iM
\r
I
C.P.
S
I
'
100
i : \,
d i
I
I
Ammoniuni dichroniate,
(XHi)zCrSO;
80
1
~
I
b
I5
4
WAVE LENGTH IN MICRCUS
1
<
S
,I
0
I
z
IO
I
I
WAVE NUMBERS H
laa
I
0
II
I
I1
I
I4
Ib
WAVE LEN6TH IN MKRONS
W'
IUD
9
1100
im
iim
WAVE HUMERI IN W1
iiw
ID^
ua
m
b15
700
im
IC4
M
W
Potassium dichromate.
K~CTSOT
L-nk.
i
fbQ
M
;;"
40
:
Y
m
20
.
0
I
3
row urn
nm
0
5
WAVE UNOW
b
7
IN I ~ O N S
WAyt NUMlERS IN C Y '
IUD
Imo
IUD
iua
9
8
iim
IIW
itw
IO
imo
I1
I1
I3
WAVE LEMGTH IN MKROM
WAVE NUMDERS IN C M '
9m
em
IS
I4
7m
Ib
bl5
Calcirini dichromate.
CaCrzO;.SHrO
C.P.
1
O
I *Y
I
II
4
I
1
5
WAVE LINGW
7
b
m
WRONS
8
*
10
I1
I1
WAVE LENGTH IN MKROHS
ANALYTICAL CHEMISTRY
1288
IW
~
I4I
~
P
i
1
Copuer dichromate,
C uCr& .S H 2 0
II S
110
i P.
\r
A
m~
I
5"
$ 1
I
I
1
I
4a
I
I
I
10
M
I
I
0
S
4
7
b
I
9
IO
I
I
10
I/
,I
.
I
1
0
I5
Ib
>odium molybdate.
SaAfo0~2HzO
.4 R
Iopdurn
-2
lwo
ludm
Iffl
AT
M
P
I
$@
M
I
*
I
/
Z"
\
!~
:
Y
20
C.P.
i
~
I
2
P
molybdate,
I 43:Im Potassium
KzMoo4.mo
1
i
\J
I
I
P
f
10
I
'10
~
O
1
I
4
'
-" . I
S
b
WAE W T H M UCRONS
l o
8
9
0
,I
1
I1
WAVE LENOlH IN W C U S
I,
IS
b
,4z .4 m nion u ni
I
\
/
W
/
s
F
53 -,pf,
J
M
I"
he1)tamolybdate
~NH~)s~Io;Ou.4HiO
-
x
U
I
.1R
4
10
10
0
0
1
1
4
5
b
7
WAVE LENOM IN MICRONS
8
V
IO
!
1
1
I.
I5
I6
WAVE LENOW IN WCRONS
WAVE NUMBfRS IN C M '
5
lm
Sodium tungstatr,
S~~WOL~IIIO
(0
c P.
M
10
1
I
I
5
b
7
WAVE LEN6M IN MICRONS
D
.
0
,I
WAVE I 1LEN6TH 111 11
MKRONI
I.
I5
Ib
1289
Potassium tungstate
KzWO4
C.P
Calcium tungstate
Caw04
Pure
WAVE NUMIIERS IN C M '
15% I100
I1W
IM
IIW
em
Iwp
..
WAY€ WMERS IN CMI
800
'15
7m
I
I
'
-,i
\
,~
',
I48
~,-.--
I4
?
~
Sodium permanganate.
NaMnOc3HzO
C.P
bo
'
1
"i,:
I
*
f
-
i
I
10
;,
W
1
0
3
1
4
I
5
6
7
WAVE LENGTH IN MICRONS
9
IO
WA-
WAVE NUMlElS vi C M '
yxxl
Mm
UD)
IW
1m
2mo
lxx)
lux)
llm
,100
IIW
Imo
.m
I3
I2
I
0
I4
15
W l H IN Y C I C U S
b
W A M NWlERS IN W-l
7m
8rn
b25
im
10
I4
E
5
AR
= 60
M
4
-
5
Potassium permanganate,
KhlnOi
40
10
P
10
20
0
1
4
5
b
WAVf LEN6TH IN MICRMIS
7
8
1,
11
11
W A M LWOTH IN MICRONS
I.
0
I5
Ib
Calcium permanganate,
Ca(MnOa)z.4Hn0
C P
ANALYTICAL CHEMISTRY
1290
Bariuui permanganate
Ra(3lnOi)z
C.P.
Sodium ferroeyanide,
SaiFe(CN)s.lOH.O
C.P
Potas.ium ferrocyanide,
KqFe(CX"i).3I1~0
hK
sbx rom
'
rn
2rm
15m
-
Im
10
\
f
n
Ef M
I
E
II
\,
4
110
Pure
i~
60
10
I
,I
*
IO
IIO
I
I
l
I
0
I
4
Ca!cium ferrocyanide,
CarFe(CN)s.l2H>O
I54
I
I
J I
I
I
J
5*
I
I
I
5
b
7
I
O
9
0
I
I1
,I
I,
I5
Ib
Potassium ferricyanide,
KsFe(CN)s
AR
V O L U M E 24, NO. 8, A U G U S T 1 9 5 2
5WO
IMo
1wP
2x4
WAVE NUMBERS IN C M 1
1x4 I r n
1wP
I1W
1291
IIW
IIW
WAVE NUMBERS IN C M '
lca
aw
VW
615
7W
Sodiuiii coliultiriitritr
NarCo iSO.!*
f-
~
I
1
I
1
LO
1 -
%
. K
I
I
I
I
i
1
I
I
157Iw
r-\
I
I
'e
I
~
10
AR
Barium chluride,
BaC12.2H10
.i R
ANALYTICAL CHEMISTRY
1292
Table IV.
1.0
1
Eniiwion
Sa
I.;
Ca
To explore this possibility, u
series of eight synthetic mixtures
wa? prepared and analyzed independently by the three techniques. ( A photographic x-ra!.
procedure was used.) This iriformation was then pooled, thr
data were re-esamined, and ii
combined analysis was obtained.
The test was not completel!fair because it, was known that
infrared spectra have been ohtained for nearly all the inorganic salts in the laboratory, and
that t'hese same salts would he
used in making up the mixtures.
I n addition, t,he components
n-ere mixed in roughly equ:il
amounts by bulk.
The results are shoa-n in
Table IT'. The analysis of misture 3 is discussed in greater
detail below. I t is apparent
that no one of the techniques by
itself is powerful enough to give
a complete analysis of even these
idealized unknoums. This is
partl)- because there was no prior
information about the caontent of
the samples, and therefore every
possibility had to be considered.
-1s xith any other anal)
much more detailed and reliahlr
Use of Infrared Spectra in Qualitative Anal>-sis
Independrnt d n a l y - e .
Infrared
SaHCOi
Final
Cornbined
rinalysis
X-ray
Actual
Composition
WaHCOi
CaCOr
KSOi
NH4NO.I
SO,--Silica eel
4T14SOI
Very poor pattern
B
Silica gel
.II
Ph
x
Yellon
4
I'ellon-
Na
ICKr20;
K
N a S C S or N H i K S
Cr
Ifp(cloi)?
Sulfide odor
Ph Y
Cd
SiL?HlOi
Bi
B
Sa
AI
K*CI.yOi
NaSCN
AIg(ClO,)?"
Pb 1
Sothing
Very poor p a t t e r n
KilCrzOi
S-aSCX
RSCS
CaS0. L H j O
NazBIO; 10H?O
CdS
SaBiOx '!
SatBaO; IOtLO
CdS
')
c ?P
.\IO
Ca
I.;
S a '?
Sr 11
K*S?O6
CaCOa
PhCrO4
KazSOr Y
Caar PO, I 2
Sh
Si
P
ca
C
P?
Ba
Na
I.
.11 ?
SI.? 7
KaI.03
Ba(K0s
A nitrate; prohahly BaPhSOI '?
isos)?.possibly SaSOz
Other component(s)
Possibilities:
Another nitrate, SaBrOl. Sa?WO, or
K?\VOi. S a l l o O , or K l l o O ~
Changing the positive ion may produce a different crystallin? arrangement, resulting in a
different symmetry or iiitensity of the electrical
field around a negative ion.
A difference in t,he type or extent of hydration
probably alters some of the frequencies.
Cm-1
700
600
8 BO;
840:
3
c coj
a
nco;
3
SILICATES
N NOi
NO:
900
1100
!OW
1200
Z
4
s
Y
soq
¶
*A
L l
1
-
II
L
nso;
3
5
ClOi
Br Br 0;
I lo;
v voj
c, c,o;
GE .o=
!
* s
i
- k
l
i
I
-1-
1
3
4
I
3
3
2
8
,
5
A
4
600
Figure 2.
700
800
900
1000
1100
IPW
1300
1400
Characteristic Frequencies of Polyatomic Inorganic Ions
m, w. Strong, medium, weak
sp. Sharp
s.
-
L
*LP
No h b o i 2
w wo;
3
Mn MnOZ
-
A
s20j 2
szoi 2
se sao;
2
s*o;
c uo;
A
,
1
IO
s20g
-
+
NH;
17
P Po:
9
HPOq 6
H PO' 5
2. 4
5 SO;
6
1400
1300
-21
SCN'
the other hand Hunt, J\-isherd, and Bonham
( 5 ) found that for anhydrous carbonates there is
an approximately linear relationship between the
wave length of the 11- to 12-micron band and the
logarithm of the mass of the positive ion(s). Hunt
has kindly pointed out that, the authors' data
tit his curve, with the exception of lit,hium carbonate.
Characteristic Frequencies of Inorganic Ions.
Just as with sulfates and nitrates, most other polyatomic ions exhibit characteristic frequencies.
These are summarized in Figure 2 . It is evident
that they are distinctive and that they do not have
a great spread in wave numbers.
Qualitative Analysis. The usefulness of these
charactei,istic frequencies in qualitative analysis is
obvious. It appeared that the infrared spectrum
might give, rapidly and easily, some information
about the polyatomic ionE that are present in an unknoivn inorganic mixture. If only one or two compounds are involved, it might, even be possible to
narrow the possibilities to a fex- specific salts. It
also seemed that a combination of infrared, emission, and x-ray analysis might be very effective.
Presumably emission analysis would determine the
metals, infrared would say something about the
polyatomic ions, and x-ray analysis might, give
their combinat,ion into specific salts.
011
800
3
* In most, but not all, examples
** Literature value
V O L U M E 2 4 , NO. 8, A U G U S T 1 9 5 2
1293
results can be obtained if there is some advance information
ahout the nature of the unknowns. However, Table I\- also
shoTvL: that the three techniques are nicely complementary, and
th:it together they are capable of providing a considerable amount
of information even when such prior knowledge is lacking. Although thrre are two or three surprising errors in the combined
:inaI?ws, the over-all rwults are verj- encouraging. It is espec-iall:. noteworth>-that the actual chemical compounds are giveir
iri miny ca.vs.
WAVE N U M B S IN CM.1
15W1400
1100
1100
IIW
1000
tain possibilities for the x-ray analysis which greatly simplify
its interpretation.
The advantages of this physical analysis include small sampk
requirement, reasonable time, and the ability t o determine the
actual compounds in man>- cases. I t is evident, too, t'hat any
or all of these three techniques are valuable preliminaries to a
ishemica1 analyis on an unknown material, especially a quantitative one.
Variability of Spectra. It is not uncommon to find that the
spectra of t,wo samples of the same compound are somewhat different. There
are several possible reasons for thin.
In the spectra of sodium
IMP~RITIES.
cyanide, potassium cyanide, and potassium cyanate (Xos. 21, 22, 23) bands
have been marked that are plainly due to
60
the corresponding carbonates and bicar2=
bonates.
CRYSTALORIESTATIOX. It is well
knonm that the spectra of anisotropic
y
crystals depend on the orientation of
8
the sample. Consequently it is desirable
io
t o have completely random orientation
of the crystallites to avoid such effects.
This is an additional rewon for grinding
L
p
d
0
the sample very finely.
I5
Ib
8
9
IO
11
12
I3
I4
WAVE LENOTH IN MICRONS
PoLnioRPmsai. Different crystalline
forms of the same compound are often
Figure 3. Portion of Infrared Spectrum of Lead S i t r a t e
raDable of eshibitine slightly
., . different
infrared spectra ( 2 1 1..
WAVE NUMBERS IN C M '
\ . A R Y I S G DXGREES
O F HYDRATIOX.
1200
1100
1000
900
800
~
t>
8
I
-4
0
IO
II
WAVE LENGTH,
Figitre 1 .
I n vier\
caw
12
I
2
5
y
,
I3
1.1
Znonialous H a n d in Unknown 3
(:a301 .hould be w r i t t e n C a S 0 ~ . 2 A ? 0
Isi)i\-ii)i..ii, Ti:i.iisrui I.>.
S-I,:~?.
:in;ilysis of a conipletely
o i r i i ~ \vhi~11
~
thrr(J art' nlow than two
unknowi sani~)IeI ~ ~ ~ i ~tiiffii.ult
coniponc~ntr. It is not :i1)plii,:iI)lv t o noncrystallinc material..
( r f . unknown 2 ) and runs into troul)lc \\-ith substances that gaiii
01' lose water of hydi,ation readily.
I n both c5ase.q infmred i i
often a rcliable tool.
Suhstanc~eslike metal osides, hytirosides, and sulfides gener:illy h:ivcl no sharply defined infrared absorption from 2 t o 10
i d e from possible water and 0-H bands. On the ot1rc.r
y are often good samples for x-ray analysis (vf. cadmium sulfide in unknown 4).
The principal fault with emission analysis is its great sensitivity :
it is frequently difficult t o distinguish between major components
:ind impurities. This fact arcounts for t,he surprising oversight
01 cdcium in unknoivn 2 , and tungsten in 8.
Infrared examination has advantages over wet chemistry for
detecting the more unusual ions, such as BOz-, B407--, SzOs--,
and S?Os--, since these are not included in the usual schemes of
The proper sequence in using these techniques is the order
cniission, infrared, and then s-ray. The first two present rer-
Several esamples of variable spectra have been otiserved, lor
Lvhirh the muse is not definitely knonn. Tn-o different samples
of potassium metabisulfite, KzS206,were esaniincd, and proved
to have different, patterns of band intensities in one region (see
curve 104). I n potassium carbonate there is a hand a t 880
c m - ' or a t 865 em.-', and in one spectrogram out of a total of
ten hoth hands appear. There is no cleai correlation b e t w e n
position and water content.
Figure3 shows that the mode of preparation is important. It
rompares the spectra of two lead nitrate samples, one prepared
nornially with Sujol and one with very little Sujol. Differmces near 1300 rm.-l and 880 t o TOO cm-I are striking. This
may be an orientation effect.
X more baffling case of unexpected variation was ol)serveil
with unknon-n S o . 3. In analyzing this by infrared, calcium
sulfate dihydrate was missed completely and magnesium percahlorate \\-as reported in its place. The reason is brought out in
Figure 4. Pure calcium sulfate dihydrate has a single broad
lmnd centered near 1140 cm.-' (8.8 microns), whereas in inisture 3 a strong doublet was observed a t 1080 and 1140 cni.-l
Thtx origin of the doublet was puzzling berause no other ($omponcnt of 3 but calcium sulfate has a band near here. Calcium
sulfate dihydrate had been run as a Nujol mull and mixture 3
as a dry powder. Reversing each did not change their spectra.
Then calcium sulfate dihydrate was mised with each of the other
components in turn in the dry state, and the mixtures \wre es:mined as Nujol mulls. It \vas found that the misture with
ium thiocyanate gave a doublet. \Tith sodium thiorj-anate there was also a doublet, but it TI-as much less pronounced.
It seems unlikely t,hat a chemical reaction between calcium
sulfate dihydrate and potassium thiocyanate could account for
these peculiar results, bemuse the materials are in the solid state.
Two other possible causes are changes in crystal structure, presumably caused by changing the hydrate, and an orientation
effect. The following observat,ions seem to rule out variable
water content as a cause, and suggest the orientation effect.
A calcium sulfate dihydratepotavsium thiocyanat'e mixture
heated a t 170' C. for 3 days gave the two bands near 1100 em.-'
Only one band was found after the salt plates were separated
and t h e mull e ~ p o s e dt o air for an hour.
A N A L Y T I C A L CHEMISTRY
1294
Another portion of the same heated mixture was esposetl to air
under more humid conditions for an hour and then mulled in
Nujol: two bands again resulted.
This mull was opened to the air for an additional half hour,
and only one band was found.
\\-hen calcium sulfate dihydrate alone was heated overnight
a t 170" C., three bands were found. The sulfate vibration absorbing near 1100 cni.-l is triply degenerate (12), and this may be a
case of splitting of the degeneracy as a result of altering the crystal symmet'ry. Finally, potassium sulfate has exhibited a similar variability in this same band,
.
~
_-_
Table V. Characteristic Frequencies i n Complex Ions
Complex I o n
Fe(CN)s--Fe(CKjc---Fe(CS)sNO--
cm.- 1
2100
-2010
2140
1923
847
Ce(S0ds- -
1336
1430
745
SO?
1080
1260
1420
1530
Simple Ion
csC?i cs -
XO (gac)
SOP
SO,-
cm.-1
2070-80
2070-80
2070-80
1878
820-33
1235-80
1328-80
i26-40
815-35
...
13.40-80
I t is much safer to base arguments on the identity of spectra
than on their nonidentity. >lore empirical experience with the
spectra of salts from many different' sources should improve
t,his situation.
Miscellaneous Observations. AXOMALOUS
DISPERSION
ANU
CHRISTIAXSEN
FILTER
EFFECTS.These have been adequately
described in the literature ( 5 , 9). Examples will be seen in the
steep-sided band of magnesium carbonate a t 3 microns (No. 13),
of sodium thiocyanate near 5 microns (No. 26), and of potassium
ferricyanide near 5 microns ( S o . 155).
WATERAXD HYDROXYL
BAXDS. The sharpness of the \\-ater
bands near 3 and 6 microns in sodium and magnesium perchlorate (Nos. 117, l l S ) , and the high value of their 0-H stretching
frequency ( >3500 cm.-I), are striking. Apparently t'here is
very little hydrogen bonding in these salts. It, is interesting t o
note that animoniuni perchlorate (KO. 116), \vhicah forins no
hydrate, has a high K-H stretching frequency. Other compounds
with sharp water bands are barium chlorate (KO.115) and 1)ai~iuni
chloride (No. 159).
I n bicarbonate there is a band a t 2500 to 2600 cni.-', in Iiisulfate at 2300 to 2600 cm.-' (very broad), and in HPOI--, H2P04-,
HAs04--, and HP;IsO4-at about 2300 em.-' (very broad). Their
is evidence that these are 0-H stretching frequencies of the
hydroxyl groups attachrd to the rentral atom.
B.%RInf CHLORIDE.Several chlorides of the purely ionic
type were examined to observe how the hands due to watcr of
hydrat,ion varied. Among these was barium chloride dihydrate
( S o . 159). Surprisingly it has a strong band a t 700 cm.-',
which )\-as totally unexpected but was c,onfirnied on a second
sample. I t is not attributable to carbonate or bicmhonate, hut
may tie due to a torsional motion of the w:itcr molecules in tlic
lattice.
COMPLEXIoss. The rliaracteristic. frequcncic:; carry over
moderately wcll into roinplex ions-for exainple, pot
ricyanitie has a band a t 2100 c m - l , and each of the rhree ferrocyanides has one near 2010 cni-'. This is obviously thc stretching frequency of the C S - gi'oupj which in simplr ryanides is
2070 to 2080 c i n - ' Other examples are shon.n in Tnl)le V.
CoIiPoazrns WITH So ABSORPTIOS.Sickel hydroxide, fci~ic*
oside, cadmium sulfide, and mercuric sulfide have no absorption
in the rock salt rcgion aside from watcr mid hydroryl hands.
ACLYO&LEl)(;\I
EX1
The authors are inciel)ted to two colleagues, D. T. P i t i i i x i i
and E. S. Hodge, for carrying out t h r x-ray and emission analyses, respectively. Helen Golob prepared many of the curvrs.
The Chemistry Departments of the University of Pittsburgh
and Carnegie Institute of Technolog!- graciou3ly provided many
of t,he samples.
LITERATURE CITED
Colthup, N. E . , ,I. Optical S o c
40 397 (lCJ50'.
Glockler, G., Rec. M u d e r n I'hys., 15, 111 (1913).
Hersberg. G., "Infrared and Raman Spectra of Polyatomic
Molecules." Sew I-ork. D. Van Noatrand Co., 1945.
(4) Hihhen, J. H., "The Ranian Effect and Its Chemical -ippIications." S e w York. Reinhold Puhlishinrr Coru.. 1939.
( 5 ) Hunt, J . M.,Wisherd. 11.P., and Ronhani, L. k., .is\r.,C H i c v . ,
22, 1478 (1950).
Lecomte. J., AM^. Chim. d c t n . 2, 727 (1948).
(7) Lecomte, J.. C'ahiers p h y s . . 17, I (1943!, and referelives cited
therein.
(8) Sewman, It.. and €Idford, R. S.. .I. C'Aem. Phys.. 18, 1 2 i 6 , 1 9 1
(6)
(1950'.
(9) Price, TT. C.. and Tetlow, K. S . , I b i d . , 16, 1157 (194q).
(10) Schaefer, C.. and Xlatossi, F.. "Das ultrarote Spektrum," Herlin, Julius Springer., 18:30; repi.inted by Edwards Bi,os., Inc.,
Ann Arbor, l f i c h .
(11) \Vagner, E. L., and I-Ioi,nig, D. F.,J . Chem. P h y s . . 18, 296, 305
(1950).
(12) Wu, Ta-You, "Vibrational Spectra and Structure of Polyatomic Molecules," 2nd ed., .%nn .%I hor, Mich., J. W.ICcIwat ds.
1946.
RECEITED
for review July 3 , 1931
.ici.epted J u n e 7 , 19z2