Reaction of platinum(II) derivatives with bis(pyrazolyl)propane. cleavage of a C( sp3)-N bond in a bis(pyrazolyl)alkane promoted by platinum(II) derivatives. crystal structure of cis-PT(pzH) 2Cl 2 (pzH = pyrazole)

Abstract

The reactions of bis(pyrazolyl)propane (CH 3) 2C(pz) 2, (pzH = pyrazole), with PtCl 2, (RCN) 2PtCl 2 and K 2[PtCl 4 have been investigated, and the results compared with those described previously for the corresponding palladium(II) derivatives. In contrast with the behaviour of the palladium analogues, the platinum derivatives promote the rupture of the ligand: simple adducts of pyrazole, cis- or trans-Pt(pzH) 2Cl 2, or species containing the ligand [HNC(R)pz], formally arising from the insertion of a nitrile into the NH bond of pyrazole, are obtained. For comparison, the reaction of the platinum derivatives with pyrazole itself has been investigated under various conditions. The crystal structure of cis-Pt(pzH) 2Cl 2 has been determined by X-ray diffraction: monoclinic, space group C2/ c, a 9.180(1), b 15.084(1), c 15.1445(9) Å, β 101.536(7)°, Z - 8, R = 0.039, R w = 0.040 for 2125 observed reflections.