Supramolecular chemistry of organoplatinum(IV) complexes: A syndiotactic polymer with uracil substituents

Abstract

The reaction of RCH2X with [PtMe2(DPA)], 1, (DPA = di-2-pyridylamine) has given [PtXMe2(CH2R)(DPA)] by cis oxidative addition to give 2a, when R = 6-uracil, X = Cl, or 3a, when R = CO2H, X = Br, but by a mixture of cis and trans oxidative addition to give 4a/4b when R = 4-C6H4CO2H, X = Br. The unusual cis stereochemistry of oxidative addition is rationalized thermodynamically by the formation of an intramolecular hydrogen bond in 2a and 3a but not 4a, and kinetically by the role of the ligand DPA NH group in hydrogen bonding to halide. Complex 2a in the solid state forms an unusual supramolecular syndiotactic polymer by forming two different intermolecular NH..O=C hydrogen bonds to neighbouring molecules.