Cadmium dicarboxylate coordination polymers incorporating a long-spanning organodiimine: in situ alkene isomerization and an unprecedented chiral 658 two-dimensional network

Reaction of cadmium nitrate, maleic acid, and N, N'-bis(4-pyridylmethyl) piperazine (bpmp) in a methanol/water mixed solvent system at 25 degrees C resulted in an unexpected in situ isomerization and formation of {[Cd(fumarate)(bpmp)(H2O)(2)] center dot 2H(2)O}(n) (1), which exhibits a system of mutually interpenetrated [Cd(fumarate)(bpmp)(H2O)](n) grid-like coordination polymer layers. A similar reaction using cadmium chloride and succinic acid produced {[Cd(succinate)(bpmp)(CH3OH)] center dot 2H(2)O}(n) (2), which manifests a chiral two-dimensional coordination polymer network with an unprecedented 658 topology. The differences in the conformations of the four-carbon dicarboxylate tethers (anti in 1, gauche in 2) and cadmium coordination environment (octahedral in 1, pentagonal bipyramidal in 2) play a significant role in structure direction during self-assembly. Thermal properties of 1 and 2 are also reported.