TY - JOUR
T1 - Zirconium Complexes with Phosphinomethanide Ligands
T2 - Syntheses, Reactivity, and X-ray Structure Determinations
AU - Karsch, Hans H.
AU - Grauvogl, Gregor
AU - Kawecki, Michael
AU - Bissinger, Peter
AU - Kumberger, Otto
AU - Schier, Annette
AU - Müller, Gerhard
PY - 1994/2/1
Y1 - 1994/2/1
N2 - The reactions of ZrCl4 with lithium phosphinomethanides were investigated. With LiCH2PMe2, 1, and Li[CH(PMe2)2], 2, the products could not be characterized satisfactorily. With {(TMEDA)Li[CH (PMe2) (SiMe3)]}2, 3, a mixture of compounds Cl(4-n)Zr[CH(PMe2)(SiMe3)]n (n = 1–4), 4a‒d, was obtained and characterized spectroscopically. Various coordination modes of the phosphinomethanide ligands are observed for n = 3 (4c) and n = 4 (4d) by means of NMR spectroscopy With (TMEDA){Li[C(PMe2)(SiMe3)2]}2,5, only disubstitution is observed, and Cl2Zr[C(PMe2)(SiMe3)2]2, 6, containing hexacoordinated Zr, was isolated in high yield as red crystals (monoclinic, C2/c, with a = 9.273(1) Å,b = 15.078(2) Å,c = 22.062(2) Å, β = 95.09(1)°, Z = 4, wR = 0.025). Complex 6 in toluene solution inserts CO into a Zr-C bond, and after a subsequent 1,2-silyl shift a phosphino enolate complex is formed, which dimerizes to give {Cl2Zr [C (PMe2) (SiMe3)2] [OC (SiMe3)=C(SiMe3)PMe2] }2, 7 (yellow crystals: monoclinic, P21/n, with a = 10.149(1) Å, b = 16.503 (2) Å, c = 19.307(3) A, β = 97.13(1)°, Z = 2, wR = 0.031). In THE solution 6 also inserts CO, and spectroscopic evidence indicates a mixture of two compounds: the phosphorus ylide (Me3Si)(Me3SiO)C=C(PMe2)PMe2=C(SiMe3)2 (=L), 8, an LZrCl2,9. With the lithium diphosphinomethanides (D)Li[C(PR2)2(SiMe3)] (D = —, R = Me, 5a; D = TMEDA, R = Ph, 5b; D = TMED A, R = Me, 5c), the hexacoordinate complex Cl2Zr[C(PMe2)2(SiMe3)]2, 10, and the ionic species [(TMEDA)2Li]{Cl3Zr[C(PR2)2(SiMe3)]2), 11 (R = Ph) and 12(R = Me), with heptacoordinated zirconium are obtained, and the latter both were characterized by X-ray structure determinations: 11, red crystals, orthorhombic, Pbca with a = 19.016(2) Å, b = 32.385(4) Å, c = 23.906(3) Å, Z = 8, wR = 0.070; 12·2MePh, red crystals, monoclinic, P21c with a = 16.138(2) Å, b = 13.837(1) Å, c = 25.779(3) Å, β = 102.19(1)°, Z = 4, wR = 0.051.
AB - The reactions of ZrCl4 with lithium phosphinomethanides were investigated. With LiCH2PMe2, 1, and Li[CH(PMe2)2], 2, the products could not be characterized satisfactorily. With {(TMEDA)Li[CH (PMe2) (SiMe3)]}2, 3, a mixture of compounds Cl(4-n)Zr[CH(PMe2)(SiMe3)]n (n = 1–4), 4a‒d, was obtained and characterized spectroscopically. Various coordination modes of the phosphinomethanide ligands are observed for n = 3 (4c) and n = 4 (4d) by means of NMR spectroscopy With (TMEDA){Li[C(PMe2)(SiMe3)2]}2,5, only disubstitution is observed, and Cl2Zr[C(PMe2)(SiMe3)2]2, 6, containing hexacoordinated Zr, was isolated in high yield as red crystals (monoclinic, C2/c, with a = 9.273(1) Å,b = 15.078(2) Å,c = 22.062(2) Å, β = 95.09(1)°, Z = 4, wR = 0.025). Complex 6 in toluene solution inserts CO into a Zr-C bond, and after a subsequent 1,2-silyl shift a phosphino enolate complex is formed, which dimerizes to give {Cl2Zr [C (PMe2) (SiMe3)2] [OC (SiMe3)=C(SiMe3)PMe2] }2, 7 (yellow crystals: monoclinic, P21/n, with a = 10.149(1) Å, b = 16.503 (2) Å, c = 19.307(3) A, β = 97.13(1)°, Z = 2, wR = 0.031). In THE solution 6 also inserts CO, and spectroscopic evidence indicates a mixture of two compounds: the phosphorus ylide (Me3Si)(Me3SiO)C=C(PMe2)PMe2=C(SiMe3)2 (=L), 8, an LZrCl2,9. With the lithium diphosphinomethanides (D)Li[C(PR2)2(SiMe3)] (D = —, R = Me, 5a; D = TMEDA, R = Ph, 5b; D = TMED A, R = Me, 5c), the hexacoordinate complex Cl2Zr[C(PMe2)2(SiMe3)]2, 10, and the ionic species [(TMEDA)2Li]{Cl3Zr[C(PR2)2(SiMe3)]2), 11 (R = Ph) and 12(R = Me), with heptacoordinated zirconium are obtained, and the latter both were characterized by X-ray structure determinations: 11, red crystals, orthorhombic, Pbca with a = 19.016(2) Å, b = 32.385(4) Å, c = 23.906(3) Å, Z = 8, wR = 0.070; 12·2MePh, red crystals, monoclinic, P21c with a = 16.138(2) Å, b = 13.837(1) Å, c = 25.779(3) Å, β = 102.19(1)°, Z = 4, wR = 0.051.
UR - http://www.scopus.com/inward/record.url?scp=0011675460&partnerID=8YFLogxK
U2 - 10.1021/om00014a036
DO - 10.1021/om00014a036
M3 - Article
AN - SCOPUS:0011675460
SN - 0276-7333
VL - 13
SP - 610
EP - 618
JO - Organometallics
JF - Organometallics
IS - 2
ER -