A novel linking Schiff-base type ligand (L: py-CH=N-C6H4-N=CH-py) and its zinc coordination polymers:: Preparation of L, 2-pyridin-3-yl-1H-henzoimidazol, trans-[Zn(H2O)4L2]•(NO3)2•(MeOH)2, [Zn(NO3)(H2O)2(L)]•(NO3)•(H2O)2, and [Zn(L)(OBC)(H2O)] (OBC=4,4′-oxybis(benzoate))

A long, bis(monodentate), linking Schiff-base ligand L (py-CH=N-C6H4-N=CH-py) was prepared from 1,4-phenylenediamine and 3-pyridinecarboxaldehyde by the Schiff-base condensation. Ligand L has two terminal pyridyl groups capable of coordinating to metals through their nitrogen atoms. In contrast, the same reaction between 1,2-phenylenediamine and 3-pyridinecarboxaldehyde produced a mixture of imidazol isomers (2pyridin-3-yl-1H-benzoimidazole), which are connected to one another by the N-H center dot center dot center dot N hydrogen bonding to form a tetramer. From Zn(NO3)(2)center dot 6H(2)O and ligand L under various conditions, one discrete molecule, trans[Zn(H2O)(4)(L-2]center dot(NO3)(2)center dot(MeOH)(2), and two 1-D zinc polymers, [Zn(NO3)(H2O)(2)(L)]center dot(NO3)center dot(H2O)(2) and [Zn(L) (OBC)(H2O)], were prepared. In ligand L, the N center dot center dot center dot N separation between the terminal pyridyl groups is 13.994 A, with their nitrogen atoms at the meta positions (3,3') in a trans manner. The corresponding N center dot center dot center dot N separations in its compounds range from 13.853 to 14.754 angstrom.