Supplementary Material
Elaborated spectral analysis and modeling calculations on Co(II), Ni(II),Cu(II),
Pd(II), Pt(II) and Pt(IV) nanoparticles complexes with simple thiourea derivative
GAMIL A.A. Al-HAZMI, ADEL A. El-ZAHHAR, KHLOOD S. ABOU-MELHA, FAWAZ A. SAAD,
MOHAMED H. ABDEL-RHMAN, ABDALLA M. KHEDR and NASHWA M. El-METWALY*
Thermal decomposition kinetics
In order to assess the effect of metal ion on the thermal behavior of the complexes, the order (n)
and the energy of activation (E) of the various decomposition stages were determined from TG
curves. Several equations [S1-S8] have been proposed as means of analyzing TG curves and
obtaining values for kinetic parameters. Different studies [S1-S4] have discussed the advantages
of this method over the conventional isothermal methods. The rate of the decomposition process
can be described as the product of two separate functions of temperature and conversion using:
d
dt = k(T ) f (α)
(1)
where α is the fraction decomposed at time t, k(T) is the temperature dependent function and f(α)
is the conversion function dependent on the mechanism of decomposition. The temperature
dependent function k(T) is of Arrhenius type and can be considered as the rate constant k,
K = A e-E*/ RT
(2)
where R is the gas constant in (J mol-1 k-1) substituting equation (2) into equation (1) we get this
equation:

A
d

dT
 e-E* RT
 
(3)
where φ is the linear heating rate dT/dt. From the integration and approximation, this equation
can be obtained in the following form:
1
ln g ( ) 
 AR 
E *
 ln 

RT
 E * 
(4)
where g(α) is a function of α dependent on the mechanism of the reaction. The integral on the
right hand side is known as temperature integral and has no closed for solution. So, several
techniques have been used for the evaluation of temperature integral. Most commonly used
methods for this purpose are the differential method of Freeman and Carroll [S1], the integral
methods of Coats and Redfern [S3], and the approximation method of Horowitz and Metzger
[S8]. The kinetic parameters for the ligand and some of its complexes are evaluated using the
following methods and the results are in good agreement (table S1) with each other. The used
methods are discussed briefly.
Coats-Redfern equation
The equation is a typical integral method, represented as:

d
A 2
 E * 

0 (1   )n  T exp  RT dt
1
T
(5)
For convenience of integration, the lower limit T1 is usually taken as zero. This equation on
integration gives:
  ln 1    
 AR  E *
ln 
  ln 

2
T
  E *  RT


(6)
Plot of ln   ln 1     (LHS) against 1/T was drawn. E* is the energy of activation in Jmol -1 and
2

T

calculated from the slop and A is (S-1) from the intercept value. The entropy of activation ∆S* in
(J K-1mol-1) was calculated by using the equation:
 Ah 
S *  R ln 

 K BT s 
(7)
where kB is the Boltzmann constant, h is the Plank’s constant and Ts is the peak temperature
[S8].
2
Horowitz-Metzger equation
The derived relation could be as:
ln   ln 1     
E

RT m
(8)
where α is the fraction of sample decomposed at time t and   T T m .
A plot of ln   ln 1     against  was found to be linear from the slope of which E was
calculated and Z can be deduced from the relation:
Z 
 E 
E
exp 

2
RT m
 RT m 
(9)
where  is the linear heating rate, the order of reaction, n, can be calculated from the relation:
n  33.64758  182.295 m  435.9073 m2  551.157 m3  357.3703 m4  93.4828 m5
(10)
where  m is the fraction of the substance decomposed at T m .
Also, the decomposition kinetics were calculated for the free ligand and its Pd(II), Co(II), Cu(II)
and Pt(IV) complexes (table S1). The second decomposition step was chosen as the suitable for
the calculations except for the Ni(II) and Pt(II) complexes due to the overlapping of steps, which
prevent the exact determination. The kinetic parameters (E, A, ΔH, ΔS and ΔG) were calculated
using two methods, Coats–Redfern (CR) and Horowitz–Metzger (HM). In these methods, the
left-hand side of equations 6 and 8 was plotted against 1000/T and θ, respectively. It was
observed that the obtained values are quite comparable. The best fit was observed for (n = 1),
indicating a first-order decomposition in all cases. Different n values (e.g. 0, 0.33 and 0.66) did
not show better correlations. The value of ΔG increases significantly for complexes when
compared with the ligand. This may be through a light on a significant override in the
decomposition temperature. High ΔG values reflect that the rate of removal of the subsequent
coordinating ligand is lower, especially in thermally rigid complexes [S9, S10]. The ΔS values
3
are positive in some steps indicating a dissociation character of degradation or a consequence of
the entropy changes in-between the gaseous and solid products (formation of a new crystalline
lattice), but the negative ΔS values suggest the decomposition via abnormal pathway [S11]. The
positive ΔH values mean that the decomposition processes are endothermic and the value
overrides in complexes than the ligand. The high E values of the complexes reflect the thermal
rigidity of them. All the parameters introduce the stability of the complexes in comparison to the
free ligand which supports the concept of the complexation is yielding a thermally stable moiety
except that aggregate crystallizing water [S12]. However, it was known that the stability
constants decrease with increasing the number of ligands attached with the metal ion [S13, S14].
During the decomposition reaction a reverse effect may occur, in which the rate of removing the
remaining ligand unites is decreasing after the removal of a ligand unite or a part from.
References
[S1]
E.S. Freeman, B. Carroll. J. Phys. Chem., 62, 394 (1958).
[S2]
J. Sestak, V. Satava, W.W. Wendlandt. Thermochim. Acta, 7, 333 (1973).
[S3]
A.W. Coats, J.P. Redfern. Nature, 201, 68 (1964).
[S4]
T. Ozawa. Bull. Chem. Soc. Jpn., 38, 1881 (1965).
[S5]
W.W. Wendlandt. Thermal Methods of Analysis, Wiley, New York (1974).
[S6]
J.H.F. Flynn, L.A. Wall. J. Res. Natl. Bur. Stand. A, 70, 487 (1996).
[S7]
P. Kofstad. Nature, 179, 1362 (1957).
[S8]
H.H. Horowitz, G. Metzger. Anal. Chem., 35, 1464 (1963).
[S9]
P.M. Maravalli, T.R. Goudar. Thermochim. Acta, 325, 35 (1999).
[S10]
K.K.M. Yusuff, R. Sreekala. Thermochim. Acta, 159, 357 (1990).
[S11]
A.A. Frost, R.G. Pearson. Kinetics and Mechanism, Wiley, New York (1961).
[S12]
A.H.M. Siddalingaiah, S.G. Naik. J. Mol. Struct., 582, 129 (2002).
[S13]
V. Indira, G. Parameswaran. J. Therm. Anal. Calorim., 29, 3 (1984).
[S14]
R. Sreekala, K.K.M. Yusuf. React. Kinet. Lett., 48, 575 (1992).
4
Table S1. Kinetic parameters using the Coats-Redfern (CR) and Horowitz-Metzger (HM) operated
for the compounds.
Compounds
Steps
Thermodynamic parameters
CR
(DTGmax)
Ligand
HM
Units
1st
E
9.60104
1.10105 J mol-1
(240C)
A
ΔS
ΔH
ΔG
r
E
A
ΔS
ΔH
ΔG
r
E
A
ΔS
ΔH
ΔG
r
E
A
ΔS
ΔH
ΔG
r
E
A
ΔS
ΔH
ΔG
r
4.50107
-110
9.24104
1.40105
0.9985
2.54105
4.741015
46.3
2.57105
2.49105
0.9934
2.29105
6.111014
35.0
2.69105
2.43105
0.9950
1.50105
2.45108
-91.1
1.63105
2.36105
0.9990
1.41105
1.43108
-96.1
1.42105
2.14105
0.9991
2.51109 s-1
-67.1 Jmol-1K-1
1.12105 J mol-1
1.40105 J mol-1
0.9960
2.75105
3.541016
63.3
2.87105
2.23105
0.9930
2.61105
5.021015
47.1
2.63105
2.24105
0.9920
1.62105
8.88109
-64.5
1.35105
2.35105
0.9975
1.61105
4.53109
-67.8
1.63105
2.23105
0.9977
Co(II)-complex
2nd
(370C)
Cu(II)-complex
2nd
(437C)
Pd(II)-complex
2nd
(268C)
Pt(IV)-complex
2nd
(299C)
r = correlation coefficient of the linear plot
5
-11
0.5
HM
0.0
-13
-0.5
log log (WW)
-12
2
ln(-ln(1-) )
CR
-14
-15
-1.0
-1.5
-16
0.0017
-2.0
0.0018
0.0019
0.0020
0.0021
0.0022
0.0023
-75
-60
-45
-30
-15
0
15
30

1000/T (K)
(A)
-12.0
0.3
CR
-12.6
0.0
2
log log (WW)
-13.2
ln(-ln(1-) )
HM
-13.8
-14.4
-15.0
-0.3
-0.6
-0.9
-1.2
-15.6
-1.5
-16.2
0.00117
0.00120
0.00123
0.00126
-45
0.00129
-30
-15
0
15
30
45

1000/T (K)
(B)
-12.0
0.2
CR
0.0
-12.6
HM
-0.2
-13.2
log log (WW)
2
ln(-ln(1-) )
-0.4
-13.8
-14.4
-0.6
-0.8
-1.0
-15.0
-1.2
-1.4
-15.6
-1.6
0.001200
0.001225
0.001250
0.001275
0.001300
0.001325
-35
-28
-21
-14
-7
0

1000/T (K)
(C)
6
7
14
21
28
35
-12.4
0.15
CR
HM
-12.8
0.00
-0.15
-13.2
log log (WW)
2
ln(-ln(1-) )
-0.30
-13.6
-14.0
-14.4
-14.8
-0.45
-0.60
-0.75
-0.90
-1.05
-15.2
-1.20
-15.6
-1.35
0.001225 0.001250 0.001275 0.001300 0.001325 0.001350 0.001375
-60
-45
-30
-15
0
15
30

1000/T (K)
(D)
-12.0
0.3
CR
HM
-12.4
0.0
-12.8
-0.3
log log (WW)
2
ln(-ln(1-) )
-13.2
-13.6
-14.0
-14.4
-14.8
-0.6
-0.9
-1.2
-15.2
-15.6
-1.5
-16.0
0.00128
0.00132
0.00136
0.00140
0.00144
0.00148
-75
-60
-45
-30
-15
0
15
30
45

1000/T (K)
(E)
Figure S1. Coats Redfern (CR) and Horowitz – Metzger (HM) plots ( of the second step) of the ligand
and its Co(II), Cu(II), Pd(II) and Pt(IV) complexes ( A, B, C, D and E, respectively).
7
350
1
300
Intensity(a.u)
250
200
150
100
50
0
10
20
30
40
50
60
70
80
90
2 Theta(degrees)
500
400
Intensity(a.u)
2
300
200
100
0
10
20
30
40
50
60
2Theta(degrees)
8
70
80
90
1600
1400
3
1200
800
600
400
200
0
-200
10
20
30
40
50
60
70
80
2Theta(degrees)
350
300
4
250
Intensity(a.u)
Intensity(a.u)
1000
200
150
100
50
10
20
30
40
50
60
2Theta(degrees)
9
70
80
90
90
B
500
400
Intensity(a.u)
5
300
200
100
0
10
20
30
40
50
60
70
80
90
2Theta(degrees)
B
1400
1200
6
Intensity(a.u)
1000
800
600
400
200
0
-200
10
20
30
40
50
60
2Theta(degrees)
10
70
80
90
2500
Intensity(a.u)
2000
1500
1000
500
0
10
20
30
40
50
60
70
80
90
2 Theta(degree)
Figure S2. X-ray diffraction patterns of Pd(II), Ni(II), Pt(IV), Cu(II), Co(II), Pt(II) and ligand,
respectively.
11