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 2 L 3 (CH 3 CN) 2 ](PF 6 ) 2 ·CH 3 CN crystallises in the monoclinic space group P 2 1 / c and has unit-cell dimensions a =15.897(4), b =13.329(4), c =21.999(5) A, β =90.85(2)°, Z =4; the Cu–Cu separation is 5.201 A. The complex [Cu 2 L 4 (CH 3 CN) 2 ](PF 6 ) 2 ·0.64CH 3 CN crystallises in the monoclinic space group P 2 1 / n and has unit-cell dimensions a =17.243(5), b =11.451(6), c =26.534(8) A, β =100.08(2)°, Z =4; the Cu–Cu separation is 5.386 A. The complex [Cu 2 L 6 (CH 3 CN) 2 ](PF 6 ) 2 ·CH 3 CN crystallises in the triclinic space group P 1 and has unit-cell dimensions a =13.122(3), b =13.2116(3), c =13.718(3) A, α =104.92(3)°, β =91.96(3)°, γ =96.19(3)°, Z =2; the Cu–Cu separation is 5.215 A. In each complex there is a strongly bonded acetonitrile molecule coordinated to each copper atom. The reaction of [Cu 2 L 3 (CH 3 CN) 2 ](PF 6 ) 2 with carbon monoxide is discussed.