Effect of synthetic conditions on the structures of silver(I)-hexamethylenetetramine coordination polymers: crystal structures of two three-dimensional frameworks featuring new topological motifs

Two novel coordination complexes, [Ag-3(mu(4)-hmt)(2)(mu-ssa)(H2O)](NO3) . 3H(2)O 1, and [Ag-8(mu(3)-hmt)(2)(mu(4)-hmt)(2)(mu-pma)(2) (mu-H2O)(3)] . 18H(2)O 2 (hmt = hexamethylenetetramine, ssa = sulfosalicylate and pma = 1,2,4,5-benzenetetracarboxylate), have been prepared and structurally characterized. Crystal data: 1 C19H33Ag3N9O13S, orthorhombic, Pna2(1), a = 20.483(7) Angstrom, b = 21.890(1) Angstrom, c = 6.493(2) Angstrom, V = 2911.3(13) Angstrom(3), Z = 4; 2 C44H94Ag8N16O37, monoclinic, C2/c, a = 32.099(10) Angstrom, b = 12.916(3) Angstrom, c = 21.431(8) Angstrom, beta = 126.74(1)degrees, V = 7120(4)Angstrom(3), Z = 4. Both complexes exhibit unprecedented and different topological motifs of Ag-hmt networks. Complex 1 is a novel three-dimensional cationic network with two types of channels, in which the larger one is the largest one in Ag-hmt networks; while 2 is a three-dimensional network with cylindrical channels, consisting of mixed mu(3)- and mu(4)-hmt ligands. The results demonstrate that under different synthetic conditions, such as the presence of multiple small counter anions or different pH values, different Ag-hmt linkages may be formed to generate new three-dimensional networks. (C) 2002 Elsevier Science (USA). All rights reserved.