Displacement of norbornadiene (NBD) from Pt(CF3)2(NBD) by weak donor ligands L, and reactions of cis-Pt(CF3)2L2 with water and acids

Article abstract of DOI:10.1016/0022-328X(89)85349-5

The NBD ligand in Pt(CF3)2(NBD) has been replaced under mild conditions by a number of neutral S-, N-, and O-donor ligands to form cis-Pt(CF3)2L2 complexes (L2 = N,N,N',N'-tetramethylethylenediamine (tmen), bipyridine (bipy), ethylenediamine (en); L = pyridine (py), NH3, dimethylsulfoxide (DMSO), CH3CN, C6H5CN, N,N-dimethylformamide (DMF)).Reaction with DMSO produces predominantly the isomer cis-Pt(CF3)2(DMSO-S)(DMSO-O), with cis-Pt(CF3)2(DMSO-S)2 a minor component, as a result of steric constraints.Water or methanol attacks the CF3 groups, producing fluoride ion.The fluorine atoms of cis-Pt(CF3)2L2 (L2 = bipy, tmen; L = py) are susceptible to electrophilic attack by H⁺.Reaction with aqueous HCl or HClO4 converts one CF3 group into a coordinated CO group.With HCl, simultaneous protonation and displacement of the N-donor ligands occurred, yielding cis-Pt(CF3)(CO)Cl2^-.With HClO4, the complexes cis-Pt(CF3)(CO)L2⁺ are initially generated, with subsequent displacement of the tmen and py (but not bipy) ligands to form cis-Pt(CF3)(CO)(OH2)2⁺.The remaining CF3 group is not attacked by H⁺.Reaction of Pt(CF3)2(NBD) with halide ions in acetone initially produced the binuclear complexes <(CF3)2Pt(μ-X)2Pt(CF3)2>^2- (X = I, Cl) containing bridging halide.With larger amounts of halide ion the expected cis-Pt(CF3)2X2^2- complexes were not obtained, and instead cis-Pt(CF3)(CO)X2^- and fluoride ion were formed.When the complexes <(CF3)2Pt(μ-X)2Pt(CF3)2>^2- were kept in the presence of NBD, cis-Pt(CF3)(CO)X2^- and Pt(CF3)2(NBD) were formed.When X = I, these two complexes then reacted together to yield cis-Pt(CF3)2I(CO)^- and Pt(CF3)I(NBD).