cis-bis(2-phenylpyridine)platinum(II) (CBPPP): A simple molecular platinum compound

Abstract

Synthesis, crystal and molecular structure, electronic spectra in solution and in the solid state, electrochemical properties, the mass spectrum, and 1H, 13C, and 195Pt NMR spectra as well as some results on the reactivity of ris-PtII(Phpy)2 (I), C22H16N2Pt, are reported (Phpy- = deprotonated 2-phenylpyridine). The complex is prepared from trans-PtCl2SEt2)2 and 2-(2'-lithiophenyl)pyridine. The molecular structure reveals a pure cis form with bowlike distortions of the Phpy- ligands. In the crystal (space group monoclinic P21/n, a = 12.339 (2) Å, b = 11.790 (2) Å, c = 11.788 (3) Å, β = 106.02 (2)°, Z = 4,d = 2.029 g cm-3; diffractometer measurements, full-matrix least-square refinements, final R = 0.02, Rw = 0.023) distances are Pt-N = 2.13 Å and Pt-C = 1.99 Å. The molecules are associated to dimeric units with essentially parallel planes at a distance of 3.37 Å. The Pt-Pt distance in the dimer is 3.53 Å. A thermal motion analysis is reported. Electronic spectra feature a strong absorption band around 400 nm (Ͼ ≃ 10000), whose position depends on the solvent. No indication of molecular association is found in solution. The solid emits strongly in the range 500-600 nm at room temperature. cis-Pt(Phpy)2 reacts with Br2 in an oxidative-addition reaction to PtBr2(Phpy)2. © 1984, American Chemical Society. All rights reserved.