Construction of 3D interpenetrated dual linker coordination polymers of Zn(II) by varying the length and flexibility of bis(pyridyl) linkers

Abstract

Three new 3D coordination polymers (CPs) formulated as, [Zn(CDC)(BPy)]n (CP1), {[Zn2(CDC)2(BPyE)2].DMF}n (CP2), and {[Zn(CDC)(BPyA)].DMF}n (CP3), (where, CDC = 1,4-cyclohexanedicarboxylate, BPy =4,4′-bipyridine, BPyE = 1,2-bis(4-pyridyl)ethylene, BPyA = 1,2-bis(4-pyridyl)ethane, and DMF = dimethylformamide) have been synthesized solvothermally by employing dual linker systems using a combination of an anionic flexible cyclic dicarboxylate and altering the length and flexibility of neutral bis(pyridyl) linkers. The usage of flexible cyclic dicarboxylate in the architecture of such networks has resulted in a significant variation in topology. The diverse bis(pyridyl) linkers were primarily responsible for network modification in the synthesized CPs. These CPs (CP1–CP3) have been characterized by single-crystal X-ray diffraction, elemental analysis, FTIR spectroscopy, scanning electron microscopy, and powder X-ray diffraction. CP1 has a 2-fold interpenetrated non-porous 3D network with the point symbol {412.63} – pcu net topology. Whereas CP2 and CP3 are found to be isostructural with a porous 3D diamondoid (dia) structures featuring 4-fold interpenetrated nets. Additionally, a 3D Hirshfeld Surface analysis accompanied by quantitative 2D-fingerprint plots was used to explore the isostructurality of CP2 and CP3 as well as their intermolecular interactions.