Synthesis and reaction chemistry of 4-nitrile-substituted NCN-pincer palladium(II) and platinum(II) complexes (NCN = [NC-4-C6H2(CH2NMe2)2-2,6]-)

Nitrile-functionalized NCN-pincer complexes of type [MBr(N C-4-C6H2(CH2NMe2)(2)-2,6)] (6a, M = Pd; 6b, M = Pt) (NCN = [C6H2(CH2NMe2)(2)-2,6] ) are accessible by the reaction of Br-1-N C-4-C6H2(CH2NMe2)(2)-2,6 (2b) with [Pd-2(dba)(3) center dot CHCl3] (5a) (dba = dibenzylidene acetone) and [Pt(tol-4)(2)(SEt2)](2) (5b) (tol = tolyl), respectively. Complex 6b could successfully be converted to the linear coordination polymer {[ Pt(N C-4-C6H2(CH2NMe2)(2)-2,6)](ClO4)}(n) (8) upon its reaction with the organometallic heterobimetallic pi-tweezer compound {[Ti](mu-sigma, pi-C CSiMe3)(2)}AgOClO3 (7) ([ Ti] = (eta(5)-C5H4SiMe3)(2)Ti). The structures of 6a (M = Pd) and 6b (M = Pt) in the solid state are reported. In both complexes the d(8)-configurated transition metal ions palladium(II) and platinum(II) possess a somewhat distorted square-planar coordination sphere. Coordination number 4 at the group-10 metal atoms M is reached by the coordination of two ortho-substituents Me2NCH2, the NCN ipso-carbon atom and the bromide ligand. The N, C group is para-positioned with respect to M. (C) 2008 Elsevier B.V. All rights reserved.