Construction of diverse CdII/ZnII coordination polymers based on 5-(quinolyl)tetrazolate generated via in situ hydrothermal synthesis?

CrystEngComm Pub Date: 2012-11-27 DOI: 10.1039/C2CE26323H

Abstract

By variation of reaction parameters such as metal salts and secondary ligands, a series of new coordination polymers, [Cd(QTZ)2] (1), [Cd(QTZ)N3·H2O] (2), [Zn(QTZ)Cl] (3), [Cd2(QTZ)2(INA)2]·0.25H2O (4), [Cd2(QTZ)(btrc)·2(H2O)]·1.67H2O (5), 2[Cd3(QTZ)2(btec)·H2O]·H2O (6) (QTZ = 5-(quinolyl)tetrazole; HINA = isonicotinic acid; H3btrc = 1,3,5-benzenetricarboxylic acid; H4btec = 1,2,4,5-benzenetetracarboxylic acid) were successfully synthesized under hydrothermal reactions and structurally characterized by single-crystal X-ray diffraction. The QTZ ligands in these compounds are in situ generated from a [2 + 3] cycloaddition reaction of 3-quinolinecarbonitrile and NaN3 in water with the acid of CdII/ZnII salt. Compound 1 displays a three-dimensional (3D) 2-fold interpenetrating diamond network with Schl?fli symbol 66. Compound 2 represents a two-dimensional (2D) coordination framework constructed of infinite Cd–N3? chains and QTZ ligands. Compound 3 exhibits a 4-connected 2D (4,4) net built up by interconnection of Zn2(QTZ)2Cl2 subunits. Compound 4 is a 2D framework constructed by interconnection of Cd2(QTZ)2(INA)2 subunit and Cd2(QTZ)2 subunit. Compound 5 exhibits a 2D layered structure with the Cd2–QTZ chain extended by btrc ligands. In compound 6, trinuclear CdII clusters link each other by pairs of QTZ ligands to form an infinite zigzag Cd3–QTZ chain; furthermore the adjacent Cd3–QTZ chains are extended by the btec ligands to form a 3D network. These results indicate that QTZ is a powerful functional ligand and the nature of secondary ligands and transition metal ions also play significant roles in dominating molecular self-assembled structure. In addition, the luminescent properties of all compounds have been investigated in the solid state at room temperature.

Graphical abstract: Construction of diverse CdII/ZnII coordination polymers based on 5-(quinolyl)tetrazolate generated via in situ hydrothermal synthesis
Recommended Literature