EFFECT OF APPLIED HYDROSTATIC-PRESSURE ON THE ENANTIOSELECTIVE QUENCHING OF THE LUMINESCENCE FROM RAC-TRIS(2,6-PYRIDINEDICARBOXYLATE)TERBIUM(III) BY RESOLVED TRIS(1,10-PHENANTHROLINE) RUTHENIUM(II) IN WATER AND METHANOL

The effect of applied hydrostatic pressure on the enantioselective exc ited-state quenching of rac-tris(2,6-pyridinedicarboxylate)terbium(III ) [Tb(DPA)(3)(3-)] by optically active tris(1,1-0-phenanthroline)ruthe nium(II) [Ru(phen)(3)(2+)] is presented. The time dependence of the ex cited-state luminescence is analyzed in terms of a biexponential decay at pressures from 1 bar to 3 kbar corresponding to the diastereomeric (Delta-Delta and Delta-Lambda) quenching reactions. In water solution it is found that the diastereomeric quenching rates and enantioselect ivity increase with pressure, while in methanol solution the quenching rates and enantioselectivity decrease. The results are interpreted in terms of a detailed model for the quenching involving solvation effec ts within the diastereomeric encounter complexes.