Facial and meridional [N-C-N]- intramolecular coordination systems:: structure of fac-PtBrMe2{2,6-(pzCH2)2C6H3}•1/2C6H6{[2,6-(pzCH2)2C6H3]-=2,6-(bis{(pyrazol-1-yl)methyl}phenyl)} and mer-PtBr{2,6-(3,5-Me2pzCH2)2C6H3}, and an alternative synthetic route to the platinum(II) [N-C-N]- kernel

Intramolecular coordination by the six-membered monoanionic N,C,N chelating system 2,6-(pyrazol-1-ylmethyl)phenyl and substituted derivatives can give rise to facial and meridional coordination, exhibited by structural studies of facial. coordination in the platinum(IV) complex PtBrMe2{2,6-(pzCH(2))(2)C6H3}. 1/2C(6)H(6) and meridional coordination in the platinum(II) complex PtBr{2,6-(3,5-Me(2)pzCH(2))(2)C6H3} showing close to 'ideal' geometry for the [N-C-N](-) donor sets. A platinum(IV) complex is formed by oxidative addition of 2,6-(3,5-Me(2)pzCH(2))(2)C6H3Br to [PtMe2(SEt2)](2), but reaction with [Pt(p-Tol)(2)(SEt2)](2) gives the platinum(II) complex PtBr{2,6-(3,5-Me(2)pzCH(2))(2)C6H3} and 4,4'-bitolyl. (C) 2000 Elsevier Science S.A. All rights reserved.