Solvent-Dependent Structural Variation of Zinc(II) Coordination Polymers and Their Catalytic Activity in the Knoevenagel Condensation Reaction

Abstract

The novel self-assembled zinc(II) coordination polymers [Zn(L)(H2O)2]n (1), [Zn(L)(H2O)2]n·n(formamide) (2), [Zn(L)(H2O)2]n·n(N-methylformamide) (3), [Zn(L)(H2O)(formamide)]n (4), and [Zn3(L)2(formate)2(4,4′-bipyridine)3]n·2n(DMF)·2n(H2O) (5) (L = 5-acetamidoisophthalate) have been synthesized and characterized by elemental microanalysis, infrared spectroscopy, thermogravimetric analysis, and X-ray single crystal X-ray diffraction. 1, 2, and 3 are one-dimensional (1D) coordination polymers that crystallize in monoclinic P21, monoclinic P21/m, and triclinic P1 systems, respectively, and are pseudo-polymorphic supramolecular isomers with 1 having a helical arrangement, and 2 and 3 exhibiting zigzag type structures containing different guest molecules. Compound 4 crystallizes in the triclinic P1 space group and is a 1D coordination polymer that exhibits fused 8-membered and 16-membered dimetallic rings. Compound 5 features a two-dimensional network type polymer with trimetallic cores. Compounds 1–5 expand ...