Synthesis and Structural Analysis of a Semi-Rigid Cd(II) Coordination Polymer

A semi-rigid chiral coordination polymer, {Cd-3(4-cpta)(2)(dpp)(2)(H2O)}(n) (1), was synthesized solvothermally with 4-H(3)cpta (4-H(3)cpta = 3-(4'-carboxyphenoxy)phthalic acid), Cd(CH3COO)(2) and dpp ligand(dpp = 1,3-di(pyridin-4-yl)propane). Single-crystal diffraction analysis shows that 1 belongs to the orthorhombic system, space group Pna2(1), a = 19.112(2) angstrom, b = 13.6277(15) angstrom, c = 21.099(2) angstrom. There are two different left-handed helices in the unit cell, constructed by crystallographically independent Cd ions and organic spacers. The two helices are linked to each other as two-dimensional chiral layers via trinuclear clusters, which are further linked to become a three-dimensional semi-rigid chiral architecture. The chirality transfer in the framework is discussed.