Three Zinc(II) Coordination Polymers Based on Tetrakis(4-pyridyl)cyclobutane and Naphthalenedicarboxylate Linkers: Solvothermal Syntheses, Structures, and Photocatalytic Properties

Solvothermal
reactions of Zn­(NO3)2 with tetrakis­(4-pyridyl)­cyclobutane
(tpcb) and 1,4-naphthalenedicarboxylic acid (1,4-H2ndc)
and 2,3-naphthalenedicarboxylic acid (2,3-H2ndc) in different
solvents led to the formation of three polydimensional coordination
polymers {[Zn2(H2O)­(1,4-ndc)2(tpcb)]}n (1), {[Zn­(1,4-ndc)­(tpcb)0.5]}n (2), and {[Zn2(H2O)­(2,3-ndc)2(tpcb)]}n (3). Compounds 1–3 were characterized by elemental analysis, IR, powder X-ray
diffraction (PXRD), and single crystal X-ray diffraction. Compound 1 is a three-dimensional (3D) (3,3)-connected net with a (10·122)·(102·12) Schläfli symbol. Compound 2 holds a 2-fold interpenetrating 3D framework with a (42·62·72)·(4·62·73) Schläfli symbol, which shows hexagonal-prism-like
one-dimensional channels. Compound 3 shows a two-dimensional
(3,8)-connected network. The solid state luminescent, optical, and
thermal stability properties of 1–3 at ambient temperature were also investigated. A comparative study
on their photocatalytic activity toward the degradation of methyl
orange and methyl blue in polluted water was explored. The results
provided some interesting insights into solvent effects on the structures
of zinc­(II) coordination polymers and their photocatalytic applications.