DINUCLEAR SILVER(I) COMPLEXES OF 24-MEMBERED BIBRACCHIAL TETRAIMINE SCHIFF-BASE MACROCYCLES DERIVED FROM 2,5-DIFORMYLTHIOPHENE

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-butyl-amine in the presence of silver(I) salts yields homodinuclear bibracchial tetraimine Schiff base macrocy clic complexes. The structures of two such complexes are also reported . The complex Ag(2)L(4)(NO3)(PF6) (2) crystallises in the triclinic sp ace group P (1) over bar (C-i(l),No.2) and has unit-cell dimensions a = 12.834(6), b = 13.183(6), c = 14.588(7) Angstrom, alpha = 64.86(4), beta = 79.77(4), gamma = 69.44(3)degrees with Z = 2; there is a monode ntate and singly bridging nitrate anion present and the Ag-Ag separati on is 4.161 Angstrom. The complex Ag(2)L(4)(CH3CN)(2)(BF4)(2) . CH3CN (9) crystallises in the triclinic space group (1) over bar (C-i(l), No .2) and has unit-cell dimensions a = 9.297(4), b = 12.985(3), c = 21.7 70(5) Angstrom, alpha = 91.570(10), beta = 92.33(3), gamma = 97.92(3)d egrees with Z = 2; there is a strongly bonded acetonitrile molecule co ordinated to each silver atom and the Ag-Ag separation is 4.920 Angstr om.