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Three new thiocyanato-bridged polymers of cadmium(II), [Cd(me4dpt)(SCN)2] n (1) [me4dpt = 3,3′-iminobis(N,N-dimethylpropylamine], [Cd(me2tn)(SCN)2] n (2) (me2tn = N,N′-dimethyl-1,3-propanediamine) and [{amphyH} {Cd(SCN)3}] n (3) (ampyH = 4-aminopyridinium cation), have been synthesized and their molecular structures determined through X-ray crystallography. In Complex 1 each square pyramidal mononuclear fragment is H-bonded (N − H…S) to form a 1D supramolecular chain. Complex 2 is a 1D coordination polymer in which each distorted octahedral cadmium(II) ion is linked with the four bridging thiocyanates and one diamine. The structure of 3 reveals anionic [Cd(SCN)3]− zigzag chains arranged in an approximately hexagonal array with the 4-aminopyridinum cations occupying triangular channels. Each chain is H-bonded (N−H…N) to form a 2D supramolecular network. Upon heating, 1 and 2 melt and transform to transparent solid masses at ambient temperature over a few days. On scratching, these turn to a fine powder. Th...

Two novel polymeric networks of cadmium(II), [Cd2(ibn)(SeCN)4]n (1) (ibn=1,2-diamino-2-methylpropane) and [Cd(pyz)(SeCN)2]n (2) (pyz=pyrazine) have been synthesised and their molecular structures have been determined by X-ray crystallography. The polymer 1 consists of two 1D parallel chains of Cd(II), each having alternate tetrahedral (CdSe4) and octahedral (CdN6) Cd(II) centres bridged through selenocyanate, exhibiting symbiotic phenomena. The octahedral Cd(II) centre of one chain is linked with the tetrahedral Cd(II) centre of another chain through selenocyanate ligand resulting 1D ladder like structure. The complex 2 is a 2D network of octahedral Cd(II) (CdN4Se2) in which doubly selenocyanato bridged 1D coordination polymeric chains are linked through pyrazine ligand in a bc plane forming rectangular grid like structure.

Two novel 2D polymers of cadmium(II), [Cd(medien)(SeCN)2]n (1) (medien = N″-methyldiethylenetriamine) and [Cd2(iprdien)(SeCN)4]n (2) (iprdien = N′-isopropyldiethylenetriamine) have been synthesized and their molecular structure determined by X-ray crystallography. In complex 1 each octahedral cadmium(II) unit of a 1D coordination chain contains one pendant SeCN, binding through Se. These pendant SeCN form mutual relationships with other 1D chains through non-covalent interactions (H-bonding) giving rise to a 2D infinite sheet like structure. The molecular structure of 2 reveals a 2D infinite coordination polymer possessing alternating N-bonded octahedral and Se-bonded tetrahedral cadmium(II) centres exhibiting symbiotic phenomena. Both complexes undergo melting but complex 1 remains as a supercooled liquid in the temperature region 78–131 °C.

A unique three-dimensional coordination polymer of cadmium(II), [Cd(C4O4)(H2O)2]n1 (C4O42−⊕=⊕squarate dianion), has been synthesized and characterized by single crystal structural analysis. The molecular structure shows that each bridging squarate dianion functions as a four-fold monodentate ligand to form a cage-like channel network. The compound crystallizes in the rhombohedral system, space group R (no. 148) with a⊕=⊕b⊕=⊕11.765(6) A and c⊕=⊕14.920(7) A, γ⊕=⊕120°, Z⊕=⊕9, V⊕=⊕1788.5(15) A3. Thermal investigation reveals that the dehydrated compound is remarkably stable.