Dinucleating macrocyclic Schiff bases derived from thiophene and their metal complexes: the crystal structures of a free macrocycle and of a disilver complex

Abstract

Dinucleating macrocyclic Schiff bases derived from the condensation of thiophene-2,5-dicarbaldehyde and a number of α,ω-alkanediamines are reported together with their barium and silver complexes. The crystal structure of the macrocycle derived from 3-oxapentane-1,5-diamine, 6,19-dioxa-27,28-dithia-3,9,16,22-tetra-azatricyclo[22.2.1.1 ^11,14]octacosa-2,9,11,13,15,22,24,26-octaene, has been determined. Crystals are orthorhombic of space group P2₁2₁2₁, with a= 25.820(13), b= 14.275(6), c= 5.938(2)Å, and Z= 4. 1 629 Independent reflections with I/σ(I) > 3.0 gave R= 0.0442. The crystal structure of the dinuclear silver complex of the macrocycle derived from 3,6-dioxaoctane-1,8-diamine, [6,9,22,25-tetraoxa-33,34-dithia-3,12,19,28-tetra-azatricyclo[28.2.1.1 ^14,17]tetratriaconta-2,12,14,16,18,28,30,32-octaene-N³N¹² : N¹⁹N²⁸]–bis[aquaperchloratosilver(I)], has also been determined. Crystals are monoclinic of space group C2/c, with a= 27.941(16), b= 8.612(6), c= 15.359(9)Å, β= 102.92(5)°, and Z= 4. 855 Independent reflections with I/σ(I) > 2.0 gave R= 0.1227. In the latter structure the silver atoms are strongly co-ordinated by a pair of imine nitrogen atoms (2.27 and 2.17 Å) and by a water molecule (2.72 Å).