Coordination polymer of Co~(II) and 3,3', 5,5'-tetramethyl-4,4'-bipyrazolyl: a novel metal-organic three-dimensional network with four-coordinated planar vertices

摘要

The bitopic exodentate ligand 3,3'-5,5'-tetramethyl-4,4'-biopyrazolyl (4,4'-bpz), deigned as an angular bridging unit capable of formation of a set of coordination and hydrogen bonds, gave the coordination polymers [Co(4,4'-bpz)_2{C_6H_5CO_2}_2].2C_6H_5Br 1 and [Co(4,4'-bpz){C_6H_5CO_2} {CH_3CO_2}].2C_6H_5Br 2. Complex 1 exhibits a 3-D structure containing rectangular channels. The topology of the array has no precedents in crystal engineeringof linear spacer ligands of the 4,4'-bipyridine type and may be a prototype for engineering of a novel family of functional solids. Complex 2 exists as a hybrid coordination/hydrogen-bonded porous network which incorporate two guest bromobenzene molecules per metal atom.