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Synthesis and X-ray crystal structure of a homoleptic bismuth amide
Polyhedron Vol. 8, No. 12, pp. 15794580, Rioted in Great Britain
0277~5387189 0 1989 Pqamon
1989
S3.00+.00 Press
pk
COMLMUNICATION SYNTHESIS AND X-RAY CRYSTAL STRUCTURE OF A HOMOLEPTIC BISMUTH AMIDE WILLLAM CLEGG, NEVILLE A. COMPTON, R. JOHN ERRINGTON,* NICHOLAS C. NORMAN* and NEIL WISHART Department of Chemistry, The University of Newcastle upon Tyne, Newcastle upon Tyne NE1 7RU, U.K. (Received 27 February 1989 ; accepted 16 March 1989)
Abstract-The reaction between BiC13 and 3 equivalents of LilNphd in THF solution affords the bismuth amide complex, [Bi(NPh2)3], which has been characterized by X-ray crystallography.
Current interest in the chemistry of bismuth containing compounds is, in part, due to their importance as heterogeneous catalysts’ and more recently, as superconducting materials with high critical temperatures.’ Whilst many synthetic routes to such materials are available, any solution based methods are potentially hampered by the apparent lack of suitable precursors reported in the literature. This is particularly evident in the case of bismuth amides and alkoxides, very few reports of which exist. With regard to the former, the only accounts dealing with homoleptic complexes, of which we are aware, describe the syntheses of [Bi(NR2),] (R = Me, Et, n-Pr),3 [Bi{N(SiMe,)2}3]4 and [Bi{N(Me) SiMes)3],5 with other examples of molecules containing bismuth bound amides being [Bi(Me)2{N (Me)SiMe,}],6 [BiC12(NEt2)],7 [BiBr2(NMe2)],’ * Authors to whom correspondence should be addressed. t Spectroscopic data for 1: NMR in CD2C12, ‘H, complex multiplets centred at 6 7.2, 6.8 and 6.5, 13C{‘H} 6 151.7, 144.4, 130.0, 129.9, 124.9, 123.0, 119.0. Found: C, 60.4; H, 4.4; N, 6.0. Calc. for (&H3,,BiN3: C, 60.6; H, 4.2; N, 5.9%. $ Crystal data for 1: (&HS0BiN3, M = 713.6, triclinic, a = 10.314(2), b = 14.670(2), c = 21.292(3) A, a = 107.97(l), /3 = 9577(l), y = 99.95(1)0, V = 2977.4 A3, Z = 4, space group PT ; R = 0.104, R, = 0.058 from 4354 unique observed reflections with 20 < 45”, measured with MO-K, radiation (A= 0.7 1073 A) and corrected for absorption. Atomic coordinates, bond lengths and angles, and thermal parameters have been deposited as supplementary data with the Editor from whom copies are available on request. Atomic coordinates have also been deposited with the Cambridge Crystallographic Data Centre.
[BiI(NI-IR)~ (R = n-Pr, n-Bu)’ and [BiMe,{N(Me) SiMe,},,] (x = 1, y = 2; x = 2, y = l).’ As part of a study of bismuth chemistry in general, we have become interested in bismuth amides and report herein some preliminary results including the first crystal structure determination of this class of compound. A solution of Li[Nph;l in THF (20 cm3) was prepared from HNPh2 (1.25 g, 7.42 mmol) and Bu”Li (2.9 cm3 of a 2.5 M hexane solution, 7.42 mmol) at 0°C. After stirring for 30 min, the solution containing LiwhJ was’added to a solution of BiC13 (0.779 g, 2.47 mmol) in THF (25 cm’) and the resulting mixture was stirred for 3 h at room temperature. Removal of all volatiles, followed by extraction with toluene (3 x 15 cm3) and subsequent titration, afforded an orange solution of [Bi(NPh,)J (l), from which an orange solid was obtained upon removal of the toluene under reduced pressure. Analytically pure crystals of 1 were obtained by solvent diffusion from CH2C12 (5 cm3)-hexane (25 cm3) at - 30°C over a period of days (0.53 g, 30%), these being suitable for X-ray diffraction. Compound 1 is soluble in toluene, THF and CH2C12, and is very sensitive to traces of moisture. PhzN N
Pi’,
(1) Characterization was effected by spectroscopic and analytical methods? and confirmed by an Xray crystallographic study, the results of which are shown in Fig. 1.t Compound 1 crystallizes with two
1579
1580
Communication
Fig. 1. A diagram of the molecular structure of one of the molecules in the crystal structure of 1. Important bond length and angle data include :
A
A Bi(l)-N(11) Bi(l)-N(15) Bi(2)-N(23)
2.17(2) 2.16(3) 2.26(3)
N(l I)-Bi(lpN(13) N(ll)-Bi(lpN(lS) N(13)-Bi(lpN(15) N(21)-Bi(2)-N(23) N(21)-Bi(2)-N(25) N(23)-Bi(2pN(25)
Bi(l)-N(13) Bi(2)-N(21) Bi(2)--N(25)
2.28(2) 2.12(2) 2.21(4)
deg. 100(l) 96(l) 100(l) 101(l) 97(l) 99(l)
molecules in the asymmetric unit (one of which is shown in Fig. l), although the overall molecular geometries of each do not differ significantly and there are no short intermolecular contacts. Each bismuth centre adopts a trigonal pyramidal coordination geometry (sum of angles at Bi(1) = 296”, at Bi(2) = 297”), being bonded to three NPhz groups (av. Bi(l)-N = 2.20 A, Bi(2 jN = 2.20 A). The amido fragments contain a trigonal planar nitrogen atom with the phenyl groups twisted from coplanarity, the overall spatial arrangement being
* Spectroscopic data for 2 : NMR in C,DSCDJ, ‘H 6 0.56 (s, N(SiMe&, 13C(‘H} 6 7.5 (s, N(SiMe,),). Both signals are significantly broadened at 190 K, although limiting spectra at lower temperatures have not yet been obtained.
such as to endow the molecule with approximate C3 symmetry. We have also investigated the silylamide complex, [Bi{N(SiMe,),},] (2)4 which is readily prepared by treatment of BiC13 with 3 equivalents of L$N(SiMe,),]. Compound 2 can be isolated as a pale yellow powder in good yield by extraction of the crude reaction mixture with hexane followed by filtration and removal of all volatiles. Spectroscopic data* indicate hindered rotation about the Bi-N bonds at low temperature, a feature which would also appear to exist in 1 at room temperature judging by the complexity of the ‘H and 13C NMR spectra when compared with those of HNPhl. Finally we note that attempted preparations of
PiWr’&l
8 and [Bi{NC(Me3(CH3,C’(Me2)}31,
while resulting in transient yellow solutions, have been hindered by the apparent photosensitivity of the Bi-N bonds resulting in facile decomposition. Further studies are in progress to synthesize a wider range of bismuth amides and to explore their reaction chemistry. thank SERC and Newcastle University Small Grants Research Sub-Committee for financial support, and BP Research (Sunbury) for a CASE Award (N.A.C.). Acknowledgement-We
REFERENCES 1. Examples are the bismuth molybdate catalysts used in the SOHIO process, see R. K. Grasselli and J. D. Burrington, Ado. Catal. 1981,30, 133. 2. For a recent overview, see R. Dagani, Chem. Engng. News 1988,66 (No. 20), 24. 3. F. Ando, T. Hayashi, K. Ohashi and J. Koketsu, J. Inorg. Nucl. Chem. 1975,37,2011. 4. M. F. Lappert and P. P. Power, unpublished results (1977), taken from Metal and Metalloid Amides (Edited by M. F. Lappert, A. R. Sanger, R. C. Srivastava and P. P. Power), p. 459. Ellis Horwood (1979). 5. 0. J. Scherer, P. Homig and M. Schmidt, J. Organomet. Chem. 1966, 6, 259. 6. P. Krommes and J. Lorberth, J. Organomet. Chem. 1975,88,329 ; P. Krommes and J. Lorberth, J. Organomet. Chem. 1975,93,339. 7. K. Lal, I. P. Bhatia and R. L. Kaushik, Curr. Sci. (India) 1960,29,272; Chem. Abstr. 1961, 55, 3625. 8. K. Moedritzer, J. R. Van Wazer and H. Weingarten, U.S. Patent 3,504,005 (1970). 9. D. Hass, Z. Chem. 1964,4,185.
0277~5387189 0 1989 Pqamon
1989
S3.00+.00 Press
pk
COMLMUNICATION SYNTHESIS AND X-RAY CRYSTAL STRUCTURE OF A HOMOLEPTIC BISMUTH AMIDE WILLLAM CLEGG, NEVILLE A. COMPTON, R. JOHN ERRINGTON,* NICHOLAS C. NORMAN* and NEIL WISHART Department of Chemistry, The University of Newcastle upon Tyne, Newcastle upon Tyne NE1 7RU, U.K. (Received 27 February 1989 ; accepted 16 March 1989)
Abstract-The reaction between BiC13 and 3 equivalents of LilNphd in THF solution affords the bismuth amide complex, [Bi(NPh2)3], which has been characterized by X-ray crystallography.
Current interest in the chemistry of bismuth containing compounds is, in part, due to their importance as heterogeneous catalysts’ and more recently, as superconducting materials with high critical temperatures.’ Whilst many synthetic routes to such materials are available, any solution based methods are potentially hampered by the apparent lack of suitable precursors reported in the literature. This is particularly evident in the case of bismuth amides and alkoxides, very few reports of which exist. With regard to the former, the only accounts dealing with homoleptic complexes, of which we are aware, describe the syntheses of [Bi(NR2),] (R = Me, Et, n-Pr),3 [Bi{N(SiMe,)2}3]4 and [Bi{N(Me) SiMes)3],5 with other examples of molecules containing bismuth bound amides being [Bi(Me)2{N (Me)SiMe,}],6 [BiC12(NEt2)],7 [BiBr2(NMe2)],’ * Authors to whom correspondence should be addressed. t Spectroscopic data for 1: NMR in CD2C12, ‘H, complex multiplets centred at 6 7.2, 6.8 and 6.5, 13C{‘H} 6 151.7, 144.4, 130.0, 129.9, 124.9, 123.0, 119.0. Found: C, 60.4; H, 4.4; N, 6.0. Calc. for (&H3,,BiN3: C, 60.6; H, 4.2; N, 5.9%. $ Crystal data for 1: (&HS0BiN3, M = 713.6, triclinic, a = 10.314(2), b = 14.670(2), c = 21.292(3) A, a = 107.97(l), /3 = 9577(l), y = 99.95(1)0, V = 2977.4 A3, Z = 4, space group PT ; R = 0.104, R, = 0.058 from 4354 unique observed reflections with 20 < 45”, measured with MO-K, radiation (A= 0.7 1073 A) and corrected for absorption. Atomic coordinates, bond lengths and angles, and thermal parameters have been deposited as supplementary data with the Editor from whom copies are available on request. Atomic coordinates have also been deposited with the Cambridge Crystallographic Data Centre.
[BiI(NI-IR)~ (R = n-Pr, n-Bu)’ and [BiMe,{N(Me) SiMe,},,] (x = 1, y = 2; x = 2, y = l).’ As part of a study of bismuth chemistry in general, we have become interested in bismuth amides and report herein some preliminary results including the first crystal structure determination of this class of compound. A solution of Li[Nph;l in THF (20 cm3) was prepared from HNPh2 (1.25 g, 7.42 mmol) and Bu”Li (2.9 cm3 of a 2.5 M hexane solution, 7.42 mmol) at 0°C. After stirring for 30 min, the solution containing LiwhJ was’added to a solution of BiC13 (0.779 g, 2.47 mmol) in THF (25 cm’) and the resulting mixture was stirred for 3 h at room temperature. Removal of all volatiles, followed by extraction with toluene (3 x 15 cm3) and subsequent titration, afforded an orange solution of [Bi(NPh,)J (l), from which an orange solid was obtained upon removal of the toluene under reduced pressure. Analytically pure crystals of 1 were obtained by solvent diffusion from CH2C12 (5 cm3)-hexane (25 cm3) at - 30°C over a period of days (0.53 g, 30%), these being suitable for X-ray diffraction. Compound 1 is soluble in toluene, THF and CH2C12, and is very sensitive to traces of moisture. PhzN N
Pi’,
(1) Characterization was effected by spectroscopic and analytical methods? and confirmed by an Xray crystallographic study, the results of which are shown in Fig. 1.t Compound 1 crystallizes with two
1579
1580
Communication
Fig. 1. A diagram of the molecular structure of one of the molecules in the crystal structure of 1. Important bond length and angle data include :
A
A Bi(l)-N(11) Bi(l)-N(15) Bi(2)-N(23)
2.17(2) 2.16(3) 2.26(3)
N(l I)-Bi(lpN(13) N(ll)-Bi(lpN(lS) N(13)-Bi(lpN(15) N(21)-Bi(2)-N(23) N(21)-Bi(2)-N(25) N(23)-Bi(2pN(25)
Bi(l)-N(13) Bi(2)-N(21) Bi(2)--N(25)
2.28(2) 2.12(2) 2.21(4)
deg. 100(l) 96(l) 100(l) 101(l) 97(l) 99(l)
molecules in the asymmetric unit (one of which is shown in Fig. l), although the overall molecular geometries of each do not differ significantly and there are no short intermolecular contacts. Each bismuth centre adopts a trigonal pyramidal coordination geometry (sum of angles at Bi(1) = 296”, at Bi(2) = 297”), being bonded to three NPhz groups (av. Bi(l)-N = 2.20 A, Bi(2 jN = 2.20 A). The amido fragments contain a trigonal planar nitrogen atom with the phenyl groups twisted from coplanarity, the overall spatial arrangement being
* Spectroscopic data for 2 : NMR in C,DSCDJ, ‘H 6 0.56 (s, N(SiMe&, 13C(‘H} 6 7.5 (s, N(SiMe,),). Both signals are significantly broadened at 190 K, although limiting spectra at lower temperatures have not yet been obtained.
such as to endow the molecule with approximate C3 symmetry. We have also investigated the silylamide complex, [Bi{N(SiMe,),},] (2)4 which is readily prepared by treatment of BiC13 with 3 equivalents of L$N(SiMe,),]. Compound 2 can be isolated as a pale yellow powder in good yield by extraction of the crude reaction mixture with hexane followed by filtration and removal of all volatiles. Spectroscopic data* indicate hindered rotation about the Bi-N bonds at low temperature, a feature which would also appear to exist in 1 at room temperature judging by the complexity of the ‘H and 13C NMR spectra when compared with those of HNPhl. Finally we note that attempted preparations of
PiWr’&l
8 and [Bi{NC(Me3(CH3,C’(Me2)}31,
while resulting in transient yellow solutions, have been hindered by the apparent photosensitivity of the Bi-N bonds resulting in facile decomposition. Further studies are in progress to synthesize a wider range of bismuth amides and to explore their reaction chemistry. thank SERC and Newcastle University Small Grants Research Sub-Committee for financial support, and BP Research (Sunbury) for a CASE Award (N.A.C.). Acknowledgement-We
REFERENCES 1. Examples are the bismuth molybdate catalysts used in the SOHIO process, see R. K. Grasselli and J. D. Burrington, Ado. Catal. 1981,30, 133. 2. For a recent overview, see R. Dagani, Chem. Engng. News 1988,66 (No. 20), 24. 3. F. Ando, T. Hayashi, K. Ohashi and J. Koketsu, J. Inorg. Nucl. Chem. 1975,37,2011. 4. M. F. Lappert and P. P. Power, unpublished results (1977), taken from Metal and Metalloid Amides (Edited by M. F. Lappert, A. R. Sanger, R. C. Srivastava and P. P. Power), p. 459. Ellis Horwood (1979). 5. 0. J. Scherer, P. Homig and M. Schmidt, J. Organomet. Chem. 1966, 6, 259. 6. P. Krommes and J. Lorberth, J. Organomet. Chem. 1975,88,329 ; P. Krommes and J. Lorberth, J. Organomet. Chem. 1975,93,339. 7. K. Lal, I. P. Bhatia and R. L. Kaushik, Curr. Sci. (India) 1960,29,272; Chem. Abstr. 1961, 55, 3625. 8. K. Moedritzer, J. R. Van Wazer and H. Weingarten, U.S. Patent 3,504,005 (1970). 9. D. Hass, Z. Chem. 1964,4,185.