Synthesis and Study of the Benzyl- and Naphthylpalladium(IV) Complexes PdBrMe2(CH2Ar)(L2) (L2 = bpy, phen) and mu-Hydrocarbyl Palladium (IV)-Palladium(IV) and Palladium(1V)-Platinum(IV) Complexes and the Structure of fac-PdBrMe2(CH2-p-C6H4Br)(phen)

Abstract

Benzyl and naphthyl bromides react with dimethylpalladium(II) complexes PdMe2(L2) (L2 = bpy, phen) to form the palladium(IV) complexes PdBrMe2(CH2Ar)(L2) (Ar = p-C6H4X( X = H, Me, Br, NO2),C6F5) and PdBrMe2(CH2Ar)(bpy) (Ar = 1-C10H7, 2-C10H7). The 2,2'-bipyridyl complexes and PdBrMe2- (CH2C6F5)(phen) reductively eliminate ethane with formation of PdBr(CH2Ar)(bpy) and PdBr(CH2C6F5)(phen), respectively, on warming to ca. 40 C in (CD3)2C0. The other 1,lO-phenanthroline complexes undergo less selective reductive elimination, to form PdBr(CH2Ar)(phen) and PdBrMe(phen) in a ca. 1O:l ratio (Ar = p-C6H4Me) and ca 3:l ratio (Ar = p-C6H4X where X = H, Br, NO2). alpha, alpha'-Dibromo-meta-xylene reacts with PdMe2(bpy) to form PdBrMep(CH2-meta-C6H4CH2Br)(bpy), and this complex undergoes further oxidative addition with MMe2(bpy) (M = Pd, Pt) to form the binuclear complexes (PdBrMe2(bpy))2(mu-meta-(CH2)2C6H4) and (PdBrMe2(bpy))(PtBrMe2(bpy))(mu-meta-(CH2)2(C6hH4). The complex PdBrMe2(CH2-p-C6H4Br)(phen) has a fac-PdC3 configuration with the Pd-Br bond (2.636 (1) A) trans to the benzyl group. The Pd-C(benzy1) bond (2.091 (6) A) is ca. 0.06 A longer than the Pd-CH3 bonds.