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

Abstract

The cyclocondensation of 2,5-diformylthiophene and the amines N, N-bis-(2-aminoethyl)-2-phenylethylamine, N, N-bis-(2aminoethyl)-t-butyl-amine and N, N-bis-(2-aminoethyl)-t-butyl-amine in the presence of silver(I) salts yields homodinuclear bibracchial tetraimine Schiff base macrocyclic complexes. The structures of two such complexes are also reported. The complex Ag 2L 4(NO 3)(PF 6) (2) crystallises in the triclinic space group P l (C i l , No. 2) and has unit-cell dimensions a = 12.834(6), b = 13.183(6), c = 14.588(7) A ̊ , α = 64.86(4), β = 79.77(4), γ = 69.44(3)° with Z = 2; there is a monodentate and singly bridging nitrate anion present and the AgAg separation is 4.161 Å. The complex Ag 2L 4(CH 3CN) 2(BF 4) 2·CH 3CN (9) crystallises in the triclinic space group P l (C i l , No. 2) and has unit-cell dimensions a = 9.297(4), b = 12.985(3), c = 21.770(5) A ̊ , α = 91.570(10), β = 92.33(3), γ = 97.92(3) ° with Z = 2 ; there is a strongly bonded acetonitrile molecule coordinated to each silver atom and the AgAg separation is 4.920 Å.