SUPPLEMENTARY MATERIAL
1. Synthesis and single crystal solution of the Organic Structure Directing
Agent (OSDA).
2. Study of the self-assembling of the OSDA by Photoluminiscence spectroscopy.
3. Synthesis of ITQ-29 zeolites.
4. Structure refinement of Si,Ge-LTA and pure silica LTA.
5. Comparison of commercial LTA samples with ITQ-29 zeolites.
1
1. Synthesis and single crystal solution of the Organic Structure-
Directing Agent. a. Synthesis of the structure directing agent.
The preparation of the starting amine followed a general synthetic procedure previously described in the literature [H. Katayama, E. Abe, K.
Kaneko, J. Heterocyclic Chem. (1982), 19, 925-926]:
4.7 g of aniline (0.05 mol), 21,2 g of sodium carbonate (0.2 mol) and
126.4 g of 1-bromo-3-chloropropane (0.75 mol) were added to a reaction vessel equipped with magnetic stirring and a condenser. The reaction mixture was heated with vigorous stirring under nitrogen atmosphere by increasing gradually the temperature (from 70ºC during 1h to 160ºC for 24h). After cooling, the solution was basified with NaOH and extracted with 3 portions of ether. The organic extracts were collected, washed with water and treated with 2N hydrochloric acid. The resulting acidic extract was basified with NaOH and extracted with ether. The ether extract was washed with brine and dried over anhydrous Na
2
SO
4
. The solvent was evaporated under reduced pressure to give the amine in 85% yield. The amine was quaternized with methyl iodide as follows: A 250 ml round bottom flask was charged with 10 g (0.0578 mol) of amine and 100 ml of CHCl
3
. A solution of 24.5 g (0.173 mol) of methyl iodide was added and the reaction mixture was stirred at room temperature for three days, then new excess of methyl iodide (0.173 mol) was added and stirred at room temperature for 3 days. After 3 days new excess of methyl iodide (0.173 mol) was added and stirred at room temperature for three days. After this time a
2
solid was collected by filtration, washed exhaustively with ether and dried. The resulting ammonium salt was obtained in 89.7 % yield.
Characterization data. 13 C-NMR (200 MHz; CD
3
OD)
: 17.55, 25.17, 52.42,
65.05,130.54,131.22,131.82,140.7 ppm.
Anal. Calcd for C
13
H
18
NI(%); C:49.5; H:5.7; N:4.4.
Found: C:49.6; H,5.8; N,4.5. b. Single crystal solution of the structure directing agent (OSDA).
The structure of the 4-methyl-2,3,6,7-tetrahydro-1 H ,5 H -pirido[3,2,1ij ]quinolinium was determined by single crystal diffraction.
Crystallographic data: Formula: [C
13
H
18
N] + I · H
2
O; Triclinic, space group P1; a =
10.7663(2) Å, b = 13.5874(3) Å, c = 18.0131(4) Å, = 79.993(2)º,
=
89.723(2)º, = 89.564(2)º, V = 2594.89(9) Å 3 , Z = 8,
(CuK
) = 1.54178 Å.
A colourless single crystal of approximate dimensions 0.28
0.26
0.18 mm with prismatic shape was mounted on a glass fibber and transferred to a
Bruker SMART 6K CCD area-detector three-circle diffractometer with a MAC
Science Co., Ltd. Rotating Anode (Cu K radiation,
= 1.54178 Å) generator equipped with Goebel mirrors at settings of 50 kV and 100 mA. X-Ray data were collected at 100K, with a combination of seven runs at different
and 2
angles, 4200 frames. The data were collected using 0.3º wide
scans (5
3
sec./frame at 2
= 40º and 15 sec./frame at 2 = 100º ), crystal-to-detector distance of 4.0 cm.
The substantial redundancy in data allows empirical absorption corrections (SADABS) to be applied using multiple measurements of symmetryequivalent reflections (Ratio of minimum to maximum apparent transmission:
0.572573). A total number of 18657 reflections were collected, with 8322 independent reflections (R int
= 0.0456 and R sigma
= 0.0561). The unit cell parameters were obtained by full-matrix least-squares refinements of 8832 reflections.
Crystallographic details are given in the attached OSDA.cif file.
The raw intensity data frames were integrated with the SAINT program, which also applied corrections for Lorentz and polarization effects.
The software package SHELXTL version 6.10 was used for space group determination, structure solution and refinement. The structure was solved by direct methods (SHELXS-97), completed with difference Fourier syntheses, and refined with full-matrix least-squares using SHELXL-97 minimizing
( F
0
2 – F c
2 ) 2 .
Weighted R factors ( R w
) and all goodness of fit S are based on F 2 ; conventional
R factors ( R ) are based on F . All non-hydrogen atoms were refined with anisotropic displacement parameters. All scattering factors and anomalous dispersions factors are contained in the SHELXTL 6.10 program library. The hydrogen atom positions were calculated geometrically and were allowed to ride on their parent carbon atoms with fixed isotropic U.
The most streaking feature of the structure directing agent is that the organic cations appear as two self-assembled moieties, by an interaction
4
between aromatic rings, that trend to locate parallel one respect each other at a distance of approximately 2 Å as it is presented in figure 1.A.
Figure 1.A. Molecular simulation for the structure of minimum energy.
References.
Bruker AXS SHELXTL version 6.10. Structure Determination Package . Bruker
AXS 2000. Madison, WI.
Sheldrick, G.M. SHELXS-97, Program for Structure Solution: Acta Crystallogr .
Sect. A 1990 , 46, 467.
Sheldrick, G.M. SHELXL-97, Program for Crystal Structure Refinement;
Universität Göttingen, 1997.
Sheldrick, G.M. SADABS version 2.03 , a Program for Empirical Absorption
Correction; Universität Göttingen, 1997-2001.
SAINT+ NT ver. 6.04. SAX Area-Detector Integration Program. Bruker AXS
1997-2001. Madison, WI.
SMART v. 5.625, Area-Detector Software Package; Bruker AXS 1997-2001.
Madison, WI.
5
2. Study of the self-assembling of the OSDA by Photoluminiscence spectroscopy.
A. UV-Vis Spectra of the OSDA in water solution. The inset shows the appearance of a new band that is assigned to the dimer formation, which increases as the OSDA concentration does. (see reference 16 of the manuscript)
1,0
0,5
3
2
1
0
300 350 400
Wavelength (nm)
450
0,0
250 300 350
400 450
6
B. Photoluminescence spectrum (
ex
=265 nm) of the diluted OSDA in water solution (1
·10 -4 M), purged with nitrogen, showing a single emission band at approx. 300 nm, which is assigned to the OSDA as monomer.
2500000
2000000
Monomer
1500000
1000000
500000
0
300 400
500
7
C. Photoluminiscence spectrum (
ex
=265 nm) of the 0.3 M OSDA aqueous solution as hydroxide. (This is the same concentration than that used for the synthesis of ITQ-29). It is observed the presence of an intense emission band at ca. 450 nm. The red-shift with respect to the monomer spectrum has been attributed to the presence of π-stacking interactions between adjacent aromatic rings (ref. 16).
8
D. Solid state Photoluminiscence spectrum (
ex
=265 nm) of the Iodide salt of the OSDA. It is seen that this spectrum is very similar to that obtained in concentrated solution. Since single crystal diffraction has shown that the OSDA crystallised as dimers (see part 1 of this supplementary material), we can unambiguously assigned the observed red-shift of the emission to the π-stacking interactions between neighbored aromatic rings. Also, the same interpretation could be valid for the most concentrated aqueous solution (spectrum shown above).
200000
160000
120000
80000
300 400
500
9
E. Solid state Photoluminiscence spectrum (
ex
=265 nm) of a ITQ-29 zeolite
(sample SR346b) in the as-prepared form.
It is observed the presence of two emission bands at ca. 310 and 430 nm, which were assigned to the OSDA as monomer and dimer, respectively. The highest intensity of the second band indicates that most of the OSDA is located inside of the ITQ-29 pores forming self-assembled dimers. This is further supported by chemical analyses and 13 C-CP-MAS-NMR spectroscopy (see supplementary material 3).
1,2x10
6
8,0x10
5
4,0x10
5
300 400
500
10
3. Synthesis and characterization of ITQ-29 zeolites.
I. Detailed synthesis methods. a) Al-free ITQ-29 (sample SR346B) was synthesized in fluoride media in the presence of Ge from a gel of the following molar composition:
0.67 SiO
2
: 0.33 GeO
2
: 0.5 ROH : 0.5 HF : 7 H
2
O
The gel was prepared by hydrolyzing tetraethylorthosilicate (TEOS) in an aqueous solution of 4-methyl-2,3,6,7-tetrahydro-1H,5H-pyrido[3.2.1-ij] quinolinium hydroxide (ROH), then the appropriate amount of GeO
2
was added and the mixture was kept under stirring until the ethanol formed upon hydrolysis of TEOS and the appropriate excess of water were evaporated to reach the gel composition given above. Finally, an aqueous solution of HF (50%) was added and the mixture was introduced in a Teflon-lined stainless autoclave and heated at 150ºC for 5 days.
After this time, the autoclave was cooled down, and the mixture was filtered, washed with water and dried at 100ºC. The final composition is given in
Table 1. The zeolite was calcined at 700ºC in air. b) Al-containing ITQ-29 (sample SR386B) was synthesized in fluoride media in the presence of Ge from a gel of the following composition:
0.67 SiO
2
: 0.33 GeO
2
: 0.02 Al
2
O
3
: 0.5 ROH : 0.5 HF : 7 H
2
O
11
The gel preparation was similar to that described for the Al-free ITQ-29 with the addition of Al isopropoxide as the source of Al and seeds of ITQ-29
(5% of the total inorganic oxides), in order to promote the crystallization.
The crystallization was also carried out at 150ºC for 5 days. The final composition is given in Table 1 c) The high Al content ITQ-29 zeolite (sample SR408A) was synthesized using a mixture of OSDA´s, the quinolinium derivative and tetramethylammonium. It was obtained from a gel of the following composition:
0.67 SiO
2
: 0.33 GeO
2
: 0.07 Al
2
O
3
: 0.25 ROH: 0.25 TMAOH : 0.5 HF : 7 H
2
O
The gel was prepared in a similar way than the previously described but adding the required amount of tetraethylamonium hydroxide (TAMOH) together with the quinolinium derivative hydroxide, and seeds (5% of the total inorganic oxides) in order to promote the crystallization. Th e synthesis was carried out at 150ºC for
3 days. The final composition is given in Table 1 d) Purely siliceous ITQ-29 (sample SR455C) was prepared in fluoride media from a gel of the following composition:
1.00 SiO
2
: 0.25 ROH : 0.25 TMAOH : 0.5 HF :2 H
2
O
The gel was prepared as described for SR346B, but the addition of GeO
2 was skipped and the crystallization was done at 135ºC for 7 days . The final composition is given in table 1. The zeolite obtained was calcined at 700ºC in air.
12
e) The Al-ITQ-29 zeolite employed for the catalytic experiments (Sample
SR454A) was synthesized from a gel of the following composition:
0.91 SiO
2
: 0.09 GeO
2
: 0.02 Al
2
O
3
: 0.25 ROH : 0.25 TMAOH : 0.5 HF : 3 H
2
O
The crystallization was performed at 135ºC for 2 days. The final composition is given in Table 1
The zeolite was previously calcined at 580ºC for 3 hours in air flow before the catalytic experiments. f) Pure silicoaluminate ITQ-29 zeolite (sample SR452B) was synthesized using a mixture of OSDA´s, the quinolinium derivative and tetramethylammonium. It was obtained from a gel of the following composition:
1.00 SiO
2
: 0.01 Al
2
O
3
: 0.25 ROH: 0.25 TMAOH : 0.5 HF : 3 H
2
O
The gel was prepared in a similar way than the previously described but adding the required amount of tetraethylamonium hydroxide (TMAOH) together with the quinolinium derivative hydroxide, and seeds of pure silica LTA (10% of the total inorganic oxides) in order to promote the crystallization. The synthesis was carried out at 135ºC for 5 days. The final composition is given in Table 1
The XRD pattern shows that Al-ITQ-29 was obtained with a small impurity of
RUB-10. The Al-MAS-NMR spectrum shows a single resonance at approx. 55 ppm, indicating the tetrahedral coordination of Al in the sample. Also, this sample when calcined was able to interact with ammonia and acetonitrile, showing the accessibility of the acid sites for small molecules.
13
II. Chemical analyses and 13 C-CP-MAS-NMR spectroscopy characterization results.
The chemical compositions of the ITQ-29 samples described above are given in
Table 1.
Table 1. Chemical compositions of ITQ-29 samples expressed as molar composition per unit cell.
Sample Si
(u.c.)
Ge
(u.c.)
SR346B 16.4 7.6
Al
(u.c.)
---
C
(u.c.)
27.8
N
(u.c.)
2.1
F
(u.c.)
2.0
OSDA
(u.c.)
2.1
(a)
TMA
(u.c.)
0
SR386B 15.5 8.2 0.3 28.4 2.3 1.6 2.3
(a) 0
SR408A 14.5
SR455C 24.0
SR454A 20.7
SR452B 23.5
7.8
---
2.1
---
1.7
---
1.2
0.5
30.5
28.2
31.2
29.4
3.1
3.0
3.0
3.3
1.0
2.0
1.2
1.8
2.0
(b)
1.8
(b)
1.0
1.2
2.1
(b) 0.9
1.8
(b) 1.5
(a) Calculated from the N content.
(b) Calculated from the N and C contents and assuming no decomposition of the OSDA.
Figure 3.a. 13 C-CP-MAS-NMR spectra of the as-prepared ITQ-29 zeolites.
* indicates the spinning side bands.
14
The 13 C-NMR spectra indicate that the OSDA remains nearly intact within the pores of the ITQ-29 zeolites, as deduced from the close resemblance of the solid NMR spectra and the liquid phase spectrum of an aqueous solution of the
OSDA. In the spectra of the samples prepared in presence of TMAOH, a new signal at 58 ppm (marked as ) appears indicating that TMA + cations are incorporated into the solids. Finally, some minor decomposition products are also detected (marked as
).
15
4. Structure Refinement of Si,Ge-LTA and pure silica LTA.
Structure refinement of Ge containing ITQ-29 sample (Si/Ge = 2)
The calcined sample with Si:Ge molar ratio of 2:1 was measured in vacuum and the corresponding X ray powder diffraction (XRD) pattern is shown in Figure 4.a. This pattern was also indexed according to a cubic unit cell with refined cell parameter equal to 12.0157(4) Å. For the Rietveld refinement, the
LTA zeolite structure type with P m 3 m space group symmetry was employed.
According to the refined scattering power at the T site and assuming that it is filled, the unit cell composition of the calcined sample is Si
16.6
Ge
7.4
O
48 ,
i.e the refined Si:Ge ratio is 2.2. The averaged distance ( d ) and angles (
) from the tetrahedron are: d (TO)=1.62Å,
(O-TO) =109.4º,
(T-OT) = 153.1º. The refined atomic coordinates are listed in Table 2 and Figure 4.a. shows the very good agreement between observed and calculated XRD patterns. The details of the Rietveld refinement are given in the Experimental Section.
Atom
T [c]
O1
Table 2 . Fractional atomic coordinates [a,b] for ITQ-29 (Si:Ge=2.2) x
0.3700(1)
1/2 y
0.1840(1)
0.2118(5) z
0
0
No. of positions
24
12
Wyckoff notation k h
O2 0.2946(5) 0.2946(5) 0 12
O3 0.3370(3) 0.1095(4) 0.1095(4) 24
[a] As obtained from Rietveld refinement (space group P m 3 m ; a=12.0157(4)Å).
[b] Estimated standard deviations given in parentheses.
[c] Refined atomic occupations for site T: 0.69(2)Si+0.31(2)Ge i m
16
Figure 4.a.
Observed (crosses) and calculated (lines) XRD patterns of ITQ-29 as well as the difference profile (bottom). The short tick marks below the pattern give the positions of Bragg reflections. The arrows indicate the tow small regions excluded from the Rietveld refinement containing the diffraction lines of the platinum sample holder (Cu K
1,2
radiation).
Structure refinement of pure silica ITQ-29 sample.
The purely siliceous sample was measured after calc ination at 700ºC under air and the corresponding X ray powder diffraction (XRD) pattern is shown in Figure 4.b. This pattern was indexed according to a cubic unit cell with refined cell parameter equal to 11.8671(4) Å. For the Rietveld refinement, the
LTA zeolite structure type with P m3m space group symmetry was employed.
The refined atomic coordinates are given in Table 3 and Figure 4.b. shows the very good agreement between observed and calculated XRD patterns which confirms that ITQ-29 has LTA structure type.
17
Atom
Si
Table 3 . Fractional atomic coordinates [a,b] for pure silica ITQ-29 x
0.3683(3) y
0.1847(3) z
0
No. of positions
24
Wyckoff notation k
O1
O2
1/2
0.2939(7)
0.2179(7) x
0
0
12
12
O3 0.3429(4) 0.1098(7) y 24
[a] As obtained from Rietveld refinement (space group P m 3 m ; a=11.8671(4)Å).
[b] Estimated standard deviations given in parentheses.
h i m
Figure 4.b.
Observed (crosses) and calculated (lines) XRD patterns of pure silica zeolite A as well as the difference profile (bottom). The short tick marks below the pattern give the positions of Bragg reflections. (Cu K
1,2
radiation). To emphasize the high angle portion of the pattern, the first reflection has been cut at half height.
The refined unit cell volume is shorter by 64 Å 3 than the volume found for the Ge containing form (i.e. 1671 Å 3 in front of 1735 Å 3 ). This result is consistent with the larger ionic radius of Ge compared to Si that is also responsible of the larger averaged T-O distance obtained in the Ge zeolite ( d (T-O)=1.6
2Å) than in
18
the pure silica ITQ-29 material ( d (Si-
O)=1.60Å). The averaged distance ( d ) and angles (
) from the tetrahedron are: d (Si-
O)=1.60Å,
(O-Si-
O) = 109.4º,
(Si-
OSi) = 153.3º. It is notorious (see Table 4) that the most tensioned Si-O-Si angle is the Si-O2-
Si angle (158.4º) which correspond to the oxygen that is linking to neighboured D4R cages. On the other hand, the Si-O-Si angles corresponding to oxygen atoms placed at that small D4R cage do not seem to be strongly constrained giving Si-O1-Si and Si-O3-Si angles of 151.7 and
149.7º, respectively.
Table 4.
Bond distances in Å and bond angles in (º) with e.s.d.'s in parentheses for pure Si zeolite A.
Si - O1
Si - O2
Si - O3
1.612(5)
1.568(7)
1.606(7) (2x)
O1 - Si - O2 110.2(4)
O1 - Si - O3 108.5(5) (2x)
O2 - Si - O3 110.6(6) (2x)
O3 - Si - O3 108.5(7)
Si - O1 -Si
Si- O2 - Si
151.7(6)
158.4(9)
Si - O3 - Si 149.7(9)
The details of the Rietveld refinement are given in the Experimental Section.
Experimental section:
XRD:
The Ge containing ITQ29 sample was calcined at 700ºC for 1 hour. The pattern was measured at room temperature in vacuum on a Philips X'Pert diffractometer with Bragg-Brentano geometry using a Pt sample holder and an
19
X'Celerator detector. Intensity data obtaine d with fixed divergence slit (0.25º),
Cu K
radiation (
= 1.5406, 1.5444Å). Tube voltage and intensity: 45 kV and
40 mA. Step size and time: 0.017º 2
and 6000s.
The pure silica ITQ29 sample was calcined at 700ºC in air for 3 hours.
The pattern was measured at room temperature on a Philips X'Pert diffractometer with Bragg-Brentano geometry using a conventional flat stage holder and an X'Celerator detector. Intensity data obtained with fixed divergence slit (0.125º), Cu K
radiation (
= 1.5406, 1.5444Å). Tube voltage and intensity: 45 kV and 40 mA. Step size and time: 0.017º 2
and 6000s.
Rietveld refinement:
The Rietveld refinement of Ge-ITQ-29 data was performed with LSP7 using a 2
range from 13.5º to 64.2º with the regions between 39.344 - 40.177 and 45.701 - 47.220 excluded due to the appearance in these regions of the
(111) and (200) Pt diffraction peaks of the sample holder. The transmission coefficient at the Pt(111) Bragg position is 0.35 which was used for correcting the finite film thickness of the sample. Number of contributing reflections is 86.
No geometric restraints used. Number of structural parameters is 7. Number of profile parameters is 8, including unit cell parameters and zero shift (0.020º 2
) with visually estimated background (Average background = 38.000 counts).
Profile function used was Pearson VII. Refined overall thermal vibration coefficient B = 6.0Å 2 . The residuals of the refinement were R wp
=0.026,
R p
=0.018,
2 =5.0.
The Rietveld refinement of the pure silica-ITQ-29 data with LSP7 was performed using the measured 2
range from 5º to 75º. Number of contributing
20
reflections is 186. No geometric restraints used. Number of structural parameters is 7. Number of profile parameters is 8, including unit cell parameters and zero shift (0.055º 2
) with visually estimated background
(Average background = 400 counts). Profile function used was Pearson VII.
Refined overall thermal vibration coefficient B = 0.7Å 2 . The residuals of the refinement were R wp
=0.097, R p
=0.062, R
B
=0.032,
2 =2.8.
21
5. Comparison of commercial LTA samples with ITQ-29 zeolites.
The XRD patterns of different commercial LTA zeolites are given for comparison purposes.
Zeolite 3A is the potassium form of the LTA zeolite, having the following composition:
0.6 K
2
O: 0.40 Na
2
O : 1 Al
2
O
3
: 2.0 ± 0.1SiO
2
: x H
2
O
4A is the same zeolite, but in the sodium, its formula is:
1 Na
2
O: 1 Al
2
O
3
: 2.0 ± 0.1 SiO
2
: x H
2
O
Finally, 5A is the Ca 2+ exchanged material with the following composition
0.80 CaO : 0.20 Na
2
O : 1 Al
2
O
3
: 2.0 ± 0.1 SiO
2
: x H
2
O
(all of them were purchased from Aldrich Co.)
As can be seen, all the commercial LTA samples posses a framework Si/Al ratio close to 1.
22
In the figure, It can be seen there that the peak intensities greatly depend on the nature of the exchanged cation located within the cavities of the LTA structure.
Also, the X-ray diffraction lines of pure silica ITQ-29 zeolite are shifted towards low 2θ values (i.e. higher d spacing), due to the smaller ionic radii of Si than that of Al. However, the formation of pure silica LTA can be unambiguously confirmed from the absence of non assigned diffraction lines and the goodness of Rietveld refinement.
23