Effect of phenyl substitution on bonding in η<sup>3</sup>-benzyl complexes of platinum
作者:Louise E. Crascall、John L. Spencer
DOI:10.1039/dt9950002391
日期:——
Reaction of the platinum(0) styrene complexes [Pt(eta 2- CH2=CHC(6)H(4)X)Bu(2)(t)P(CH2)(3)PBu(2)(t)}] 1a-1f (X = Br-3, Br-4, Me-4, F-4, F-3 or MeO-4) with MBF, in diethyl ether afforded the eta(3)-methylbenzyl complexes [Pt(eta(3)-MeCHC6H4X)Bu(2)(t)P(CH2)(3)PBu(2)(t)}][BF4] 2a-2f. The effect of phenyl substitution on the asymmetry of the eta(3)-methylbenzyl interaction was measured by P-31-H-1} NMR spectroscopy and it was found that, in general, the more electron releasing the substituent, X. the more asymmetric is the bonding. Complexes 2a-2f lose styrene reversibly to form the hydride-bridged dinuclear platinum complex [Pt-2(mu-H)(2)Bu(2)(t)P(CH2)(3)PBu(2)(t)}(2)][BF4](2). Displacement of styrenes from 2a-2f by ethene and bicyclo[2.2.1]hept-2-ene affords known complexes stabilized by a three-centre, two-electron (agostic) bond.