Decarboxylation syntheses of transition metal organometallics

The complexes P t[C 6 F 4 - o -C(O)O ](PPh3)L (L = py, 2,4-Me2C5H3N or 2,6-Me2C5H3N) and P t[C 6 F 4 - o -C(O)O ]L2 [L2 = (Ph2PCH2)2 or (Ph2P)2(CH2)3] have been prepared by decarboxylation reactions between cis-PtCl2(PPh3)2 or PtCl2L2 and thallium(I) tetrafluorophthalate in boiling pyridine, or 2,4- or 2,6-dimethylpyridine. Reaction of cis-PtCl2(PPh3)2 with o-C6F4(CO2Tl)2 in pyridine at room temprature gives Pt[o-(O2C)2C6F4](PPh3)2, which undergoes decarboxylation at 160–165°C in the absence of a solvent to give P t[C 6 F 4 - o -C(O)O ](PPh3)2. 31P NMR data suggest that in P t[C 6 F 4 - o -C(O)O ](PPh3L comlexes, triphenylphosphine is trans to the coordinated oxygen. The crystal structure for L = 2.6-Me2C5H3N as a chloroform solvate shows a,b,c,d-Pt(O,C,P.N) square planar stereochemistry with 2,6-dimethylpyridine near perpendicular to the coordination plane and the tetrafluorophenyl ring near coplanar with this plane.