HETEROBIMETALLIC (PD,PT,CU) COMPLEXES OF HEXAPYRAZOLYLCYCLOTRIPHOSPHAZENE<i>VIA</i>SIMULTANEOUS GEMINAL (N₂) AND NONGEMINAL (N₃) COORDINATION MODES

Abstract

Abstract Synthesis and spectroscopy of four heterobimetallic compounds containing the metal centres Cu(II)-Pd(II) and Cu(II)-Pt(II) with the multidentate nitrogen donor ligand hexakis (3,5-dimethyl-pyrazolyl)cyclotriphosphazene, (HPCTP) are reported. The complexes HPCTP·CuCl2·MX2 (M = Pd, X = Cl (3) or Br (4) and M = Pt, X = Cl (5) or Br (6)) were obtained by treating the metal-containing ligands HPCTP°CuX2 X = Cl(l) or Br(2)) with M(PhCN)2Cl2(M = Pd or Pt). The electronic absorption spectra and electron paramagnetic resonance data indicate the copper in these compounds has a distorted trigonal bipyramidal geometry. A single crystal X-ray determination of 4 is reported. The crystals of 4 are monoclinic with a = 10.570(2), b = 28.863(4), c = 16.009(1)Å, β = 98.71(2)°, V = 4827(1)Å3, Z = 4, D c = 1.65 g cm−3 and space group P21/c. The geometry about copper is trigonal bipyramidal with mean distances of Cu-N(pz) = 1.987(13), Cu-N(ctp) = 2.352(11) and Cu-Cl = 2.315(10)Å while that of palladium is square planar with distances of Pd-N(pz) = 2.045(11) and Pd-Br = 2.384(6). While copper is coordinated through two nongeminal pyrazolyl nitrogen atoms and a cyclophosphazene ring nitrogen atom, coordination to palladium is through geminal pyrazolyl nitrogen atoms.