COORDINATION OF CB11H12-TO CATIONIC ZIRCONIUM(IV) COMPLEXES - SYNTHESIS AND STRUCTURES OF (C5H5)2ZR(ETA-2-CH2PH)(CB11H12), (C5H4ME)2ZR(CH3)(CB11H12), AND (C5ME5)ZR(CH3)2(CB11H12)
Dj. Crowther et al., COORDINATION OF CB11H12-TO CATIONIC ZIRCONIUM(IV) COMPLEXES - SYNTHESIS AND STRUCTURES OF (C5H5)2ZR(ETA-2-CH2PH)(CB11H12), (C5H4ME)2ZR(CH3)(CB11H12), AND (C5ME5)ZR(CH3)2(CB11H12), Organometallics, 12(8), 1993, pp. 2897-2903
The reaction of Ag[CB11H12] with CP2Zr(CH2Ph)2 yields CP2Zr(eta2-CH2Ph
)(eta1-CB11H12) (1), in which the carborane coordinates to Zr via a si
ngle B-H-Zr bridge involving the B-H bond trans to the carbon of the c
loso CB11H12- anion. Data for 1: a = 9.802(5) angstrom, b = 13.663(5)
angstrom, c = 10.860(4) angstrom, beta = 92.48(4)-degrees, V = 1453(2)
angstrom3, Z = 2, in space group P2(1)/m. A similar structure is obse
rved for CP'2Zr(CH3)(eta1-CB11H12) (2, Cp' = C5H4Me), which is prepare
d by reaction of CP'2Zr(CH3(2 with Ag[CB11H12]. Data for 2: a = 13.504
(2) angstrom, b = 19.432(3) angstrom, c = 7.919(1) angstrom, V = 2078(
1) angstrom3, Z = 4, in space group Pnn2. The reaction of CpZr(CH3)3
(Cp = C5Me5) with Ag[CB11H12] yields Cp*Zr(CH3)2(eta3-CB11H12) (3), i
n which the carborane coordinates in a unique tridentate fashion via t
hree B-H-Zr bridges involving the B-H bonds on a triangular face oppos
ite the carborane carbon. Data for 3: a = 12.360(3) angstrom, b = 19.4
50(4) angstrom, c = 9.161(2) angstrom, beta = 90.93(4)-degrees, V = 22
02(1) angstrom3, Z = 4, in space group P2(1)/c. Complex 1 polymerizes
ethylene, and 2 oligomerizes propene under mild conditions, while 3 is
unreactive with propene, 2-butyne, or styrene, apparently due to the
lower lability of the tridentate carborane ligand. The CB11H12- ligand
s of 1-3 are rapidly displaced by CH3CN or THF.