Structural diversity, magnetic properties and luminescence of NiII, CoII and ZnII coordination polymers derived from 3,3′-[(5-carboxy-1,3-phenylene)bis(oxy)]dibenzoic acid and 1,10-phenanthroline

Abstract

Three novel coordination polymers (CPs), namely poly[[di-μ-aqua-bis{μ4-3,3′-[(5-carboxylato-1,3-phenylene)bis(oxy)]dibenzoato-κ5 O 1:O 1′,O 3:O 5:O 5′}bis(1,10-phenanthroline-κ2 N,N′)trinickel(II)] dimethylformamide 1.5-solvate trihydrate], {[Ni3(C21H11O8)2(C12H8N2)2(H2O)2]·1.5C3H7NO·3H2O} n , (I), poly[[di-μ-aqua-bis{μ4-3,3′-[(5-carboxylato-1,3-phenylene)bis(oxy)]dibenzoato-κ5 O 1:O 1′,O 3:O 5:O 5′}bis(1,10-phenanthroline-κ2 N,N′)tricobalt(II)] diethylamine disolvate tetrahydrate], {[Co3(C21H11O8)2(C12H8N2)2(H2O)2]·2C2H7N·4H2O} n , (II), and catena-poly[[aqua(1,10-phenanthroline-κ2 N,N′)zinc(II)]-μ-5-(3-carboxyphenoxy)-3,3′-oxydibenzoato-κ2 O 1:O 3], [Zn(C21H12O8)(C12H8N2)(H2O)] n , (III), have been synthesized by the reaction of different metal ions (Ni2+, Co2+ and Zn2+), 3,3′-[(5-carboxy-1,3-phenylbis(oxy)]dibenzoic acid (H3cpboda) and 1,10-phenanthroline (phen) under solvothermal conditions. All the CPs were characterized by elemental analysis, single-crystal and powder X-ray diffraction, FT–IR spectroscopy and thermogravimetric analysis. Complexes (I) and (II) have isomorphous structures, featuring similar linear trinuclear structural units, in which the central NiII/CoII atom is located on an inversion centre with a slightly distorted octahedral [NiO6]/[CoO6] geometry. This comprises four carboxylate O-atom donors from two cpboda3− ligands and two O-atom donors from bridging water molecules. The terminal NiII/CoII groups are each connected to the central NiII/CoII cation through two μ1,3-carboxylate groups from two cpboda3− ligands and one water bridge, giving rise to linear trinuclear [M 3(μ2-H2O)2(RCOO)4] (M = Ni2+/Co2+) secondary building units (SBUs) and the SBUs develop two-dimensional-networks parallel to the (100) plane via cpboda3− ligands with new (32·4)2(32·83·9)2(34·42.82·94·103) topological structures. Zinc complex (III) displays one-dimensional coordination chains and the five-coordinated Zn atom forms a distorted square-pyramidal [ZnO3N2] geometry, which is completed by two carboxylate O-atom donors from two distinct Hcpboda2− ligands, one O atom from H2O and two N atoms from a chelating phen ligand. Magnetically, CP (I) shows weak ferromagnetic interactions involving the carboxylate groups, and bridging water molecules between the nickel(II) ions, and CP (II) shows antiferromagnetic interactions between the Co2+ ions. The solid-state luminescence properties of CP (III) were examined at ambient temperature and the luminescence sensing of Cr2O7 2−/CrO4 2− anions in aqueous solution for (III) has also been investigated.