Crystal structure, thermal and luminescent properties of the complex of zinc(II) acrylate and 4′-phenyl-2,2′:6′,2″-terpyridine

Abstract

In this work, the structure of a bifunctional metal-containing monomer of zinc acrylate (Acr) and 4′-phenyl-2,2′:6′,2″-terpyridine (PhTpy), which is used in the synthesis of self-healing polymers, is characterized for the first time. The planar structure and electron distribution in the terpyridine moieties are responsible for an extensive network of non-covalent interactions that occur during the packing of the structure, as well as for the luminescent properties. The complex was characterized using a number of physicochemical methods, such as elemental, thermogravimetric, single-crystal X-ray analysis, X-ray diffraction analysis, IR and DSC spectroscopy. The kinetic approaches were used to elucidate the thermal transformations of the obtained monomer. In addition, the activation energy of solid-state polymerization, which is attributed to the primary cleavage of the M–O bond in the carboxyl group, was estimated using two independent methods.

The complex is formulated as a co-crystalizate Zn(Acr)₂PhTpy × ZnAcrClPhTpy with a solvated water molecule. Each zinc ion is coordinated by three nitrogen atoms of the PhTpy and either two oxygen atoms of the acrylate anions or one oxygen atom of the acrylate and chloride anions and has a distorted trigonal-bipyramidal coordination environment characteristic for PhTpy transition metal complexes.