Synthesis, Structure, and Photophysical Properties of the Di‐ and Trinuclear Phosphine‐Diimine Complexes of Copper(I)

Abstract

Abstract Reactions of [Cu(NCMe) 4 ] + with stoichiometric amount of diphosphine R 2 P–(C 6 H 4 ) n –P R 2 , ( R = NC 4 H 4 , n = 1; R = Ph, n = 1, 2, 3) or tri‐phosphine 1, 3, 5‐(PPh 2 –C 6 H 4 –) 3 –C 6 H 3 ligands give the corresponding di‐ or trinuclear copper(I) acetonitrile‐phosphine complexes 1 – 5 . Substitution of the labile acetonitrile groups with chelating aromatic diimines – 2, 2′‐bipyridine (bpy), 1, 10‐phenanthroline (phen), 5, 6‐dimethyl‐1, 10‐phenanthroline (dmp), 5, 6‐dibromo‐1, 10‐phenanthroline (phenBr 2 ) – gives the corresponding substituted compounds 6 – 16 . In all complexes 1 – 16 each central Cu I atom has tetrahedral configuration completed with two N‐ and two P‐donor groups. The compounds obtained were characterized using elemental analysis, ESI‐MS, X‐ray crystallography, and NMR spectroscopy. All phosphine‐diimine compounds 6 – 16 are photoluminescent at room temperature both in dichloromethane solution and in solid state ( λ ex = 385 nm). In CH 2 Cl 2 solution the maxima of emission bands are found in a range 540–640 nm, and in solid in a similar range 538–620 nm. Emission of 6 – 16 is assigned to the triplet excited state dominated by the charge transfer transitions with contribution of the MLCT character.