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Copper(I) complexes with unsaturated nitrogen ligands. Part IV. Synthesis and structure of copper(I) monoazadiene complexes

1988; Elsevier BV; Volume: 147; Issue: 2 Linguagem: Inglês

10.1016/s0020-1693(00)83371-x

1873-3255

Lutz Stamp, Heindirk tom Dieck,

Metal-Catalyzed Oxygenation Mechanisms

Abstract M ono a za d ienes, RNCR′CR″CHR‴ (mad), readily form complexes with copper(I) salts. Complexes with a monoazadiene:copper ratio between 1:1 and 3:1 have been synthesized. The stoichiometry of the complexes formed is dependent on the nature of the anion of the copper(I) salt, the monoazadiene and the reaction conditions. The crystal and molecular structures of four complexes with different copper to monoazadiene ratios have been determined by X-ray diffraction methods. [(mad)3Cu]+[O3SCF3]- (1) (mad = C6H5CHCH CHNC6H4-p-CH3): space group R3, a = 13.373(5), c = 44.626(36) A, Z = 6; R = 0.084 for 1518 reflections; (mad)2CuCl (2) (same mad): space group C2/c, a = 12.7965(5), b = 13.855(5), c = 15.809(6) A, β = 98.67(4)°, Z = 4, R = 0.048 for 1947 reflections; [{(mad)2Cu}2Cl]+[CuCl2]- (7) (same mad): space group C2/c; a = 16.994(7), b = 15.408(5), c = 22.807(4) A, β = 102.62(2)°, Z = 4, R =0.055 for 2783 reflections; and [(mad)CuCl]2 (8) (mad= C6H5CHCHCHNCH(ipr)2): space group P212121, a = 12.399(4), b = 14.418(6), c = 19.399(19) A, Z = 4, R = 0.054 for 1815 reflections. All four examples are complexes with trigonal planar geometry around the copper atom. This underlines the importance of the coordination number three in copper(I) chemistry. The monoazadiene ligand, different from enones, coordinates in all cases via the nitrogen lone pair only and shows the all-trans configuration.