Dinuclear copper(I) complexes of 24-membered bibracchial tetraimine Schiff base macrocycles derived from 2,5-diformylthiophene

Abstract

The synthesis of dinuclear copper(I) complexes of bibracchial tetraimine Schiff base macrocycles derived from the cyclocondensation of 2,5-diformylthiophene and the amines N, N-bis-(2-aminoethyl)-2-phenylethylamine, N, N-bis-(2-aminoethyl)- n-butylamine and N, N-bis-(2-aminoethyl)- t-butylamine is described. The structures of three such complexes are reported. The complex [Cu 2L 3(CH 3CN) 2](PF 6) 2·CH 3CN crystallises in the monoclinic space group P2 1/ c and has unit-cell dimensions a=15.897(4), b=13.329(4), c=21.999(5) Å, β=90.85(2)°, Z=4; the Cu–Cu separation is 5.201 Å. The complex [Cu 2L 4(CH 3CN) 2](PF 6) 2·0.64CH 3CN crystallises in the monoclinic space group P2 1/ n and has unit-cell dimensions a=17.243(5), b=11.451(6), c=26.534(8) Å, β=100.08(2)°, Z=4; the Cu–Cu separation is 5.386 Å. The complex [Cu 2L 6(CH 3CN) 2](PF 6) 2·CH 3CN crystallises in the triclinic space group P1̄ and has unit-cell dimensions a=13.122(3), b=13.2116(3), c=13.718(3) Å, α=104.92(3)°, β=91.96(3)°, γ=96.19(3)°, Z=2; the Cu–Cu separation is 5.215 Å. In each complex there is a strongly bonded acetonitrile molecule coordinated to each copper atom. The reaction of [Cu 2L 3(CH 3CN) 2](PF 6) 2 with carbon monoxide is discussed.