W0068

Solid State Structural, Photophysical Studies, and Phosphorescence Quenching in Some Copper(I) Diimine Complexes. Andrey Yu. Kovalevsky, Milan Gembicky and Philip Coppens, Department of Chemistry, The State University of New York at Buffalo, Buffalo, New York 14260-3000.

A number of Cu(diimine)₂⁺ and Cu(diimine)P₂⁺ complexes, where diimine is a substituted 1,10-phenanthroline and P is a phosphine ligand, have been prepared and their 90K structures obtained by X-ray diffraction analysis. The geometry around copper center in different polymorphs or with different counter ions was found to be greatly affected by the crystal packing, changing from almost tetrahedral to almost trigonal pyramidal or considerably flattened. The geometry variations result in different photo-luminescent properties for a given cation crystallized with various counter-ions.

Employing an electron acceptor counter-ion or cocrystallizing a copper molecule with an electron accepting compound results in the considerable quenching of the emission. No emission was observed for Cu(dmp)₂⁺ crystallized with 9,10-anthraquinone-2-sulfonate (AQ-2-SO₃) either at room or low temperature. The phosphorescence lifetime of [Cu(dmp)(PPh₃)₂](AQ-2-SO₃) is shortened to 0.12_s, compared to 30_s measured for [Cu(dmp)(PPh₃)₂]BF₄ at room temperature. The solid state studies of the phosphorescence quenching with time-resolved EPR and absorption spectroscopy will be presented.

Support of this work by the National Science Foundation (CHE9981864 and CHE0236317) and the Petroleum Research Fund of the American Chemical Society (PRF37614-AC3) is gratefully acknowledged.