Coordination polymers in dicyanamido-cadmium(II) with diverse network dimensionalities

Abstract

The synthesis and structural characterization of six dicyanamido-cadmium(II) complexes are reported: catena-[Cd(µ1,3-dca)(µ1,5-dca)(3-ampy)] (1), catena-[Cd3(µ1,3,5-dca)2(µ1,5-dca)4(pyNO)2(H2O)2] (2), catena-{Cd(H2O)2(µ1,5-dca)2](2,6-lut-NO)} (3), catena-[Cd(Me2en)(µ1,5-dca)2] (4), catena-[Cd(Me4en)(µ1,5- dca)2] (5), and [Cd(1,8-damnp)2(dca)2] (6), where dca = dicyanamide anion, 3-ampy = 3-aminopyridine, pyNO = pyridine-N-oxide, 2,6-lut-NO = 2,6-lutidine-N-oxide,Me2en = N,N-dimethyl-ethylenediamine, Me4en = N,N,N’,N’-tetramethyl-ethylenediamine, and 1,8-damnp = 1,8-diaminonaphthaline. The coordination polymers have different dimensionalities: 1 and 5 form3D networks structures; 3 and 4 form polymeric 1D chains and 1DD double chains, respectively. Ribbons of three fused polymeric chains are observed in 2. In 6, the mononuclear complex units form a hydrogen-bonded supramolecular 3D network. In the coordination polymer compounds, the dca linkers display three bonding modes: the most common µ1,5-dca and the least popular µ1,3- and µ1,3,5-dca bonding. The luminescence emission and thermal properties of the complexes were investigated.