Synthesis and structural studies of tripodal and planar [N-C-N]- intramolecular coordination systems involving pyrazole donor groups, including oxidative addition of an aryl-bromine bond to platinum(II). Crystal structures of [PtClMe2{(pz)2CR(CH2)-N,N',C }] with R = Me or CH2Cl"

The complex [PtMe2(mu-SEt2)]2 undergoes oxidative addition reactions with chloro-2,2-bis(pyrazol-l-yl)propanes and 2,6-(pzCH2)2C6H3Br to form platinum(IV) complexes PtClMe2{(pz)2CR(CHX)-N,N',C‚ÄövÑvp} and PtBrMe2{2,6-(pzCH2)2C6H3- N, N',C‚ÄövÑvp}, respectively, with the ligands present as tripodal [N-C-N]- systems. Structural studies of two of the complexes show distorted octahedral geometry, 'fac-PtClC2N2', with (pz)2CMeCH2- and (pz)2C(CH2Cl)CH2- forming NPtN and NPtC angles at platinum ca. 7-12 degrees less than 90 degrees. The reagent 1,3-(pzCH2)2C6H4 undergoes cyclometallation with palladium(II) acetate to form Pd(O2CMe){2,6-(pzCH2)2C6H3-N,N',C‚ÄövÑvp}, which has the ligand present as a planar [N-C-N]- donor.