A set of new coordination compounds of cadmium(II)/mercury(II) halides/pseudohalides containing polyamines: Syntheses involving in situ metal-ligand reactions, crystal structures and molecular properties

Coordination compounds of the types [Hg(atta)][HgCl4] (1), [Cd-5(apda)(2)Cl-10](n) (2), [Cd-3(apda)(2)(N-3)(4)](n) (ClO4)(2n) (3) and [Cd-2(bpda)(NCS)(4)](n) (4) [atta = 4-(2-aminoethyl)-triethylenetetramine; apda = N-(2-aminoethyl) piperazine-1,4-diethylamine; bpda = N, N'-bis(2-aminoethyl) piperazine-1,4-diethylamine] are isolated using tetraethylenepentamine (tepa; for 1-3)/pentaethylenehexamine (peha; for 4) in presence of cadmium(II)/mercury(II) halides/pseudohalides. Structural studies reveal that polyamines tepa and peha undergo interesting in situ rearrangement to afford atta/apda and bpda ligands, respectively. Asymmetric unit in 1 comprises of discrete [Hg(atta)](2+) cation and [HgCl4](2-) anion. Compound 2 consists of neutral pentanuclear core [Cd5Cl10] formed by three different types of chloride bridges propagating through binucleating bitridentate character of apda to afford a 1D ladder structure. 2D coordination polymer 3 with (4(1)6(2))(4(2)6(2)) topology is formed through double mu(1,1)-and single mu(1,3)-azide bridges and binucleating behavior of apda. Alternating double mu(1,3)-thiocyanate and binucleating bis(tridentate) bridges in 4 result in a 1D zig-zag chain. Different kinds of non-covalent interactions promote dimensionalities in 1-4. Thermal behaviors of 1-4 are examined. (C) 2011 Elsevier B. V. All rights reserved.