1. Solvent, Linker, and Anion Effects on the Formation, Connectivity, and Topology of Cu(I)/PPh₃/N-Donor Ligand Coordination Polymers

Abstract

The effect of linker, anion, and solvent on the formation, topology, and connectivity of coordination polymers was investigated for polymers resulting from reactions between [Cu(MeCN)2(PPh3)2][X] (X = BF4–, ClO4–, and PF6–) and nitrogen donor ligands (pyrazine, 4,4′-bipyridine, and 3,4′-bipyridine) in three solvents (CH2Cl2, CHCl3, tetrahydrofuran (THF)). The 18 crystallization experiments with linear N-donor ligands yielded seven crystal structures of one-dimensional (1D) and five crystal structures of two-dimensional (2D) coordination polymers. The nine crystallization experiments with the nonlinear N-donor ligand yielded four crystal structures showing 1D coordination polymers. The isolated compounds with linear N-donor ligands were characterized by X-ray diffraction techniques, elemental analysis, and 1H NMR. The compounds with 3,4′-bipyridine were analyzed with single-crystal diffraction. The thermal properties of several coordination polymers were investigated by thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC) in order to determine the stability of the polymers. These techniques show that the decomposition pathway of these coordination polymers is not only determined by the topology of the polymers but also by the interchain interactions. These studies highlight that for a rational design and understanding of new coordination polymer systems one should first systematically analyze the effect of all parameters in order to filter out those ones that really determine the desired network properties.