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A simple, novel method for the preparation of metallophthalocyanines
Journal of Alloys and Compounds, 200 (1993) L7-L8 JALCOM 778
L7
Letter A simple, novel method for the preparation of metallophthalocyanines Ryszard Kubiak and Jan Janczak w. Trzebiatowski Institute for Low Temperature and Structure Research, Polish Academy of Sciences, 50-950 Wroctaw, P.O. Box 937 (Poland)
(Received April 7, 1993)
Abstract
New metallophthaiocyanines (Me-Pc) in the crystalline form were synthesized by the direct reaction between the 1,2dicyanobenzene and filings of the metallic elements or intermetallic alloys. The reaction took place at about 480 K in vacuum over a few days. Some remarks on the reaction mechanism of the Me-Pc formation are made. It is assumed that under the experimental conditions used the 1,2dicyanobenzene liquid undergoes a catalytic tetramerization. The catalytic atom of the metal is simultaneously coordinated by the forming tetramer.
1. Introduction
It is well known that many of the metallophthalocyanines can be obtained by a reaction of 1,2-dicyanobenzene with highly dispersed metals. The reaction occurred in a solvent with a high boiling point (such as trichlorobenzene, chloronaphthotoluene, quinoline, a-chloronaphthalene etc.). After reacting, the crystals were grown by sublimation under an argon or nitrogen atmosphere or by solvation and recrystallization (from dichloromethane, methanol, acetone or ethanol etc.) [1-8].
TABLE 1. The identified phases for some metals and alloys Metal/alloy
Identified products
Sn
SnPc [11, 12], /3-SnPca (monoclinic form) [13) y-SnPca (orthorhombic form) [14] /3-CuPc [15], Au SnPc [11, 12], Au PbPc triclinic form [16], Au SnPc [11, 12], In2Pc3 [17], /3-Pc [9] In2P%, a-Pc [10] In2Pc3, TIzPc [18], /3-Pc [9]
Au-Cu Au-Sn Au-Pb In-Sn In-Bi In-Tl
samples. Some selected results are shown in Tables 1 and 2.
3. Proposed mechanism of Me-Pc formation
The temperature of the Me: 1,2-dicyanobenzene (DCB) reacting mixture is only about 20 K higher than the DCB melting temperature. The closed reacting volume was previously evacuated. These conditions preserve good contact between DCB molecules and the surface of metal filings. The - C N groups of DCB are dipoles which electrically attract metal electrons. This attraction leads to a spontaneous change of sp hybridization of cyan groups and as a consequence, by prolonged heating, polymerization processes do appear. As a result, tetrameric molecules are formed (I). The tetrameric molecules have a large, open and active centre and are precursors of Me-Pc. We also have evidence that trimeric molecules are formed under the experimental conditions used. The centres of trimeric molecules are closed areas and are therefore unable to form complexes with metals (II).
2. Method
In our method we simply used the filings of certain pure metals or intermetallic alloys, made from appropriate ingots. The reaction occurred in vacuum in the following way: the filings were mixed with 1,2-dicyanobenzene and pressed into pellets. The pellets were inserted into a glass ampoule, evacuated and sealed off. The ampule was heated at about 480 K for several days. Reaction products were identified by X-ray diffraction methods on single crystals and/or powdered
0925-8388/93/$6.00
(I)
(II)
If the metal present in the reacting volume is a hard reactive or cannot form a stable complex, the main reaction products observed are crystals of the tetramer
© 1993- Elsevier Sequoia. All rights reserved
L8
Letter
TABLE 2. Crystal data of the new Me-Pc a Formula
Space group
/3-SnPc2
C2/c
InzPc3
P]
TI2Pc
Cmca
Cell parameters
Density (gcm -3)
a (,~) (o)
b (.~) t~ (°)
c (/~) 3' (°)
18.755 90 14.492 113.96 25.199 90
18.758 115.06 13.179 97.15 7.343 90
15.372 90 11.493 66.13 13.762 90
Zb
observed (flotation)
calculated
1.540
1.552
4
1.580
1.602
2
2.379
2.402
4
aThe full crystal structures will be published separately. ~Number of molecules in the unit cell.
fl--Pc [9] and/or a - P c [10] or the trimer (the trimer crystallizes in a monoclinic system with space g r o u p P21/c and lattice p a r a m e t e r s a = 4 . 0 0 0 ( 2 ) A,, b = 23.888(4) /~, c = 19.725(4) ~ and /3= 96.67(3) °. If the metal present in the reacting volume effectively attracts the f o r m e d macrocyclic molecules, then M e - P c complexes are built. However, there are no simple correlations b e t w e e n the electronic structure o f the complexing metal and the M e - P c structure formed. In the S n : D C B system three different crystal structures were f o u n d SnPc; /3-SnPc2 - monoclinic f o r m and y-SnPc2 - o r t h o r h o m b i c form. T h e probability of f o r m a t i o n of these structures increases with the D C B : S n weight ratio in the reaction volume. O n the contrary, such an effect was not observed for the DCB:T1 and D C B : I n systems. Irrespective of the DCB:T1 and D C B : I n c o n c e n t r a t i o n ratio we observed only T12Pc and In2Pc 3 respectively. M o r e o v e r T1 and In atoms show different valencies in p h t h a l o c y a n i n e complexes, although both the elements belong to the third main g r o u p o f the periodic table.
4. Conclusions 1. T h e reaction progress o f 1,2-dicyanobenzene with pure metal m a y be slower than that with an alloy possessing a metal as a c o m p o n e n t . F o r instance, indium melts u n d e r the conditions used and the particles agglomerate and so the reaction proceeds. 2. A s a rule 1,2-dicyanobenzene reacts m o r e easily with a binary alloy of an e l e m e n t and removes it f r o m the surface. T h e decline of c o n c e n t r a t i o n of a particular metal on the surface induces a c o n c e n t r a t i o n gradient. As a consequence, atoms o f the alloy are very dispersed, with reference to the atomic scale. T h e r e f o r e u n d e r these conditions they exhibit e n h a n c e d reactivity.
3. T h e reaction of an alloy with 1,2-dicyanobenzene presumably allows new phthalocyanines with m o r e than one kind of metal in the molecule to be obtained. 4. T h e m e t h o d presented allows metallophthalocyanines in the single crystal form to be obtained at relatively low t e m p e r a t u r e s (in relation to values rep o r t e d in the literature, for instance 593 K for P b P c triclinic form [15]). 5. T h e reaction o f 1,2-dicyanobenzene with an alloy m a y be useful for separating alloys into individual metals.
References 1 P.N. Moskalev and I.S. Kirin, Russ. J. Phys. Chem., 46 (1972) 1019. 2 J.F. Kirner, W. Down and W.R. Scheidt, lnorg. Chem., 15 (7) (1976) 1685-1689. 3 K. Ukei, Acta Crystallogr., B38 (1982) 1288-1290. 4 Ch.J. Schramm, R.P. Scaringe, D.R. Stojakovic, B.H. Hoffman, J.A. Ibers and T.J. Marks, J. Am. Chem. Soc., 102 (1980) 6702-6713. 5 K. Yakushi, H. Yamakado, M. Yoshitake, N. Kosugi, H. Kuroda, T. Sugano, M. Kinoshita, A. Kawamoto and J. Tanaka, Bull. Chem. Soc. Jpn., 62 (1989) 687-696. 6 W. Kroenke and M.E. Kenny, Inorg. Chem., 3 (1964) 251-254. 7 C. Clarisse and M.T. Riou, Inorg. Chem. Acta, 130 (1987) 139-144. 8 W. Kroenke and M.E. Kenny, Inorg. Chem., 3 (1964) 696. 9 R. Kubiak and J. Janczak, J. Alloys Comp., 190 (1992) 117-120. 10 J. Janczak and R. Kubiak, J. Alloys Comp., 190 (1992) 121-124. 11 M.K. Friedel, B.F. Hoskins, R.L. Martin and S.A. Marson, J. Chem. Soc. Chem. Commun. (1970)400--401. 12 R. Kubiak and J. Janczak, J. Alloys Comp., 189 (1992) 107-111. 13 J. Janczak and R. Kubiak, J. Alloys Comp., submitted for publication. 14 W.E. Bennett, D.E. Broberg and N.C. Baenziger, Inorg. Chem., 12 (4) (1973) 930-936. 15 C.J. Brown, J. Chem. Soc. A, (1968) 2488-2493. 16 Y. Iyechika, K. Yakushi, I. Ikemoto and H. Kuroda, Acta Crystallogr., B38 (1982) 766-770. 17 J. Janczak and R. Kubiak, J. Chem. Soc. Dalton Trans., in press. 18 J. Janczak and R. Kubiak, J. Alloys Comp., in press.
L7
Letter A simple, novel method for the preparation of metallophthalocyanines Ryszard Kubiak and Jan Janczak w. Trzebiatowski Institute for Low Temperature and Structure Research, Polish Academy of Sciences, 50-950 Wroctaw, P.O. Box 937 (Poland)
(Received April 7, 1993)
Abstract
New metallophthaiocyanines (Me-Pc) in the crystalline form were synthesized by the direct reaction between the 1,2dicyanobenzene and filings of the metallic elements or intermetallic alloys. The reaction took place at about 480 K in vacuum over a few days. Some remarks on the reaction mechanism of the Me-Pc formation are made. It is assumed that under the experimental conditions used the 1,2dicyanobenzene liquid undergoes a catalytic tetramerization. The catalytic atom of the metal is simultaneously coordinated by the forming tetramer.
1. Introduction
It is well known that many of the metallophthalocyanines can be obtained by a reaction of 1,2-dicyanobenzene with highly dispersed metals. The reaction occurred in a solvent with a high boiling point (such as trichlorobenzene, chloronaphthotoluene, quinoline, a-chloronaphthalene etc.). After reacting, the crystals were grown by sublimation under an argon or nitrogen atmosphere or by solvation and recrystallization (from dichloromethane, methanol, acetone or ethanol etc.) [1-8].
TABLE 1. The identified phases for some metals and alloys Metal/alloy
Identified products
Sn
SnPc [11, 12], /3-SnPca (monoclinic form) [13) y-SnPca (orthorhombic form) [14] /3-CuPc [15], Au SnPc [11, 12], Au PbPc triclinic form [16], Au SnPc [11, 12], In2Pc3 [17], /3-Pc [9] In2P%, a-Pc [10] In2Pc3, TIzPc [18], /3-Pc [9]
Au-Cu Au-Sn Au-Pb In-Sn In-Bi In-Tl
samples. Some selected results are shown in Tables 1 and 2.
3. Proposed mechanism of Me-Pc formation
The temperature of the Me: 1,2-dicyanobenzene (DCB) reacting mixture is only about 20 K higher than the DCB melting temperature. The closed reacting volume was previously evacuated. These conditions preserve good contact between DCB molecules and the surface of metal filings. The - C N groups of DCB are dipoles which electrically attract metal electrons. This attraction leads to a spontaneous change of sp hybridization of cyan groups and as a consequence, by prolonged heating, polymerization processes do appear. As a result, tetrameric molecules are formed (I). The tetrameric molecules have a large, open and active centre and are precursors of Me-Pc. We also have evidence that trimeric molecules are formed under the experimental conditions used. The centres of trimeric molecules are closed areas and are therefore unable to form complexes with metals (II).
2. Method
In our method we simply used the filings of certain pure metals or intermetallic alloys, made from appropriate ingots. The reaction occurred in vacuum in the following way: the filings were mixed with 1,2-dicyanobenzene and pressed into pellets. The pellets were inserted into a glass ampoule, evacuated and sealed off. The ampule was heated at about 480 K for several days. Reaction products were identified by X-ray diffraction methods on single crystals and/or powdered
0925-8388/93/$6.00
(I)
(II)
If the metal present in the reacting volume is a hard reactive or cannot form a stable complex, the main reaction products observed are crystals of the tetramer
© 1993- Elsevier Sequoia. All rights reserved
L8
Letter
TABLE 2. Crystal data of the new Me-Pc a Formula
Space group
/3-SnPc2
C2/c
InzPc3
P]
TI2Pc
Cmca
Cell parameters
Density (gcm -3)
a (,~) (o)
b (.~) t~ (°)
c (/~) 3' (°)
18.755 90 14.492 113.96 25.199 90
18.758 115.06 13.179 97.15 7.343 90
15.372 90 11.493 66.13 13.762 90
Zb
observed (flotation)
calculated
1.540
1.552
4
1.580
1.602
2
2.379
2.402
4
aThe full crystal structures will be published separately. ~Number of molecules in the unit cell.
fl--Pc [9] and/or a - P c [10] or the trimer (the trimer crystallizes in a monoclinic system with space g r o u p P21/c and lattice p a r a m e t e r s a = 4 . 0 0 0 ( 2 ) A,, b = 23.888(4) /~, c = 19.725(4) ~ and /3= 96.67(3) °. If the metal present in the reacting volume effectively attracts the f o r m e d macrocyclic molecules, then M e - P c complexes are built. However, there are no simple correlations b e t w e e n the electronic structure o f the complexing metal and the M e - P c structure formed. In the S n : D C B system three different crystal structures were f o u n d SnPc; /3-SnPc2 - monoclinic f o r m and y-SnPc2 - o r t h o r h o m b i c form. T h e probability of f o r m a t i o n of these structures increases with the D C B : S n weight ratio in the reaction volume. O n the contrary, such an effect was not observed for the DCB:T1 and D C B : I n systems. Irrespective of the DCB:T1 and D C B : I n c o n c e n t r a t i o n ratio we observed only T12Pc and In2Pc 3 respectively. M o r e o v e r T1 and In atoms show different valencies in p h t h a l o c y a n i n e complexes, although both the elements belong to the third main g r o u p o f the periodic table.
4. Conclusions 1. T h e reaction progress o f 1,2-dicyanobenzene with pure metal m a y be slower than that with an alloy possessing a metal as a c o m p o n e n t . F o r instance, indium melts u n d e r the conditions used and the particles agglomerate and so the reaction proceeds. 2. A s a rule 1,2-dicyanobenzene reacts m o r e easily with a binary alloy of an e l e m e n t and removes it f r o m the surface. T h e decline of c o n c e n t r a t i o n of a particular metal on the surface induces a c o n c e n t r a t i o n gradient. As a consequence, atoms o f the alloy are very dispersed, with reference to the atomic scale. T h e r e f o r e u n d e r these conditions they exhibit e n h a n c e d reactivity.
3. T h e reaction of an alloy with 1,2-dicyanobenzene presumably allows new phthalocyanines with m o r e than one kind of metal in the molecule to be obtained. 4. T h e m e t h o d presented allows metallophthalocyanines in the single crystal form to be obtained at relatively low t e m p e r a t u r e s (in relation to values rep o r t e d in the literature, for instance 593 K for P b P c triclinic form [15]). 5. T h e reaction o f 1,2-dicyanobenzene with an alloy m a y be useful for separating alloys into individual metals.
References 1 P.N. Moskalev and I.S. Kirin, Russ. J. Phys. Chem., 46 (1972) 1019. 2 J.F. Kirner, W. Down and W.R. Scheidt, lnorg. Chem., 15 (7) (1976) 1685-1689. 3 K. Ukei, Acta Crystallogr., B38 (1982) 1288-1290. 4 Ch.J. Schramm, R.P. Scaringe, D.R. Stojakovic, B.H. Hoffman, J.A. Ibers and T.J. Marks, J. Am. Chem. Soc., 102 (1980) 6702-6713. 5 K. Yakushi, H. Yamakado, M. Yoshitake, N. Kosugi, H. Kuroda, T. Sugano, M. Kinoshita, A. Kawamoto and J. Tanaka, Bull. Chem. Soc. Jpn., 62 (1989) 687-696. 6 W. Kroenke and M.E. Kenny, Inorg. Chem., 3 (1964) 251-254. 7 C. Clarisse and M.T. Riou, Inorg. Chem. Acta, 130 (1987) 139-144. 8 W. Kroenke and M.E. Kenny, Inorg. Chem., 3 (1964) 696. 9 R. Kubiak and J. Janczak, J. Alloys Comp., 190 (1992) 117-120. 10 J. Janczak and R. Kubiak, J. Alloys Comp., 190 (1992) 121-124. 11 M.K. Friedel, B.F. Hoskins, R.L. Martin and S.A. Marson, J. Chem. Soc. Chem. Commun. (1970)400--401. 12 R. Kubiak and J. Janczak, J. Alloys Comp., 189 (1992) 107-111. 13 J. Janczak and R. Kubiak, J. Alloys Comp., submitted for publication. 14 W.E. Bennett, D.E. Broberg and N.C. Baenziger, Inorg. Chem., 12 (4) (1973) 930-936. 15 C.J. Brown, J. Chem. Soc. A, (1968) 2488-2493. 16 Y. Iyechika, K. Yakushi, I. Ikemoto and H. Kuroda, Acta Crystallogr., B38 (1982) 766-770. 17 J. Janczak and R. Kubiak, J. Chem. Soc. Dalton Trans., in press. 18 J. Janczak and R. Kubiak, J. Alloys Comp., in press.