THE 3,5-DICHLOROTRIFLUOROPHENYL LIGAND, A USEFUL TOOL FOR THE STUDY OF COORDINATION MODES AND DYNAMIC BEHAVIOR OF COMPLEXES OF PALLADIUM AND PLATINUM

The square-planar complexes [MR2L2] (M = Pd, Pt; R = 3,5-C6Cl2F3) [L-2 = OPPyPh2 (Py = 2-pyridyl); SPPyPh2; OPPy2Ph; DMBI (3,3'-dimethyl-2,2 '-biindazole); OPPyPh(NHTol-p); p-TolNPPy(2)Ph] have been prepared by treating cis[MR2(THF)(2)] (THF = tetrahydrofuran) with the appropriate chelate ligands. The F-19-NMR spectra of these complexes show the pre sence of intramolecular through-space F-F couplings between ortho-fluo rine atoms of nonequivalent R groups, which provide information for th e assignment of the different ortho-fluorine signals and can be used t o study the dynamic behavior of the mentioned complexes such as: a) Ro tation of the R group in either Pd or Pt complexes, at the same or at different rates for each R groups depending on the neutral ligand; and b) exchange of the coordination sites of the chelating ligand, either by Berry or by turnstile mechanisms. The activation parameters for so me of the processes are given.