Synthesis and crystal structure of a new nickel(II) coordination polymer based on Schiff base

A new Schiff base coordination polymer, [Ni(C 18 H 16 N 3 O 2 ) 2 · 2CH 3 OH] n (C 18 H 16 N 3 O 2 , 2-acetylpyridine-L-tryptophan), was synthesized and characterized by IR, UV, and X-ray diffraction singlecrystal analysis. The crystal crystallizes in the tetragonal crystal system, space group P 4 3 2 1 2 with cell parameters a = 11.8912(11), c = 28.822(3) Å, V = 4075.5(6) Å 3 , Z = 4, F (000) = 1544, S = 1.187, ρ calcd = 1.199 g cm −3 , μ = 0.525 mm −1 , the final R 1 = 0.0515 and wR 2 = 0.1513 for 3602 observed reflections ( I > 2σ( I )). The Ni(II) atom is six-coordinated by two nitrogen atoms from C=N, two nitrogen atoms from pyridine rings and two carboxylic oxygen atoms in different ligands, forming a distorted octahedron geometry. Each ligand serves as a bridging ligand to link Ni 2+ ions through carboxylic oxygen atoms, leading to a two-dimensional coordination polymer.