ASSOCIATION OF A METHYLPLATINUM FLUOROALKOXIDE COMPLEX WITH A FLUORO ALCOHOL THROUGH O-H=O HYDROGEN-BONDING IN THE SOLID-STATE AND IN SOLUTION

X-ray crystallography of cis-PtMe(OCH(CF3)2)(PMe3)2(HOCH(CF3)2 (1) which has been prepared by reaction of cis-PtMe-(OCH(CF3)2(PMe3)2 (2) with 1,1,1,3,3,3-hexafluoro-2-propanol, reveals its molecular structure with square-planar coordination and association of the alkoxide ligand with the fluoro alcohol through O-H...O hydrogen bonding. Crystals of 1 are trigonal, space group P3(1), with a = 9.347 (6) angstrom, c = 23.317 (3) angstrom, and Z = 3. Structure calculation converged to R = 0.089 and R(w) = 0.111 for 2397 reflections with I greater-than-or-equal-to 3-sigma-(I). The short distance between two oxygen atoms in the molecule (2.63 (5) angstrom) indicates the presence of O-H...O hydrogen bonding between the alkoxide ligand and the associated alcohol. Results of calorimetric titration of complex 2 with 1,1,1,3,3,3-hexafluoro-2-propanol in toluene solutions show formation of 1 as the exclusive adduct of 2 with the alcohol in the solution. Thermodynamic parameters for association, 2 + HOCH(CF3)2 reversible 1, are obtained as DELTA-H-degrees = -24.7 kJ mol-1, DELTA-S-degrees = -46.0 J mol-1 K-1, and DELTA-G-degrees = -10.9 kJ mol-1 at 25-degrees-C in toluene.