Construction of Zn(II) Linear Trinuclear Secondary Building Units from A Coordination Polymer Based on α-Acetamidocinnamic Acid and 4-Phenylpyridine

Abstract

The synthesis and characterization of one coordination polymer and two trinuclear complexes are presented. The coordination polymer [Zn2( -O,O'-ACA)2(ACA)2(4-Phpy)2]n (1) has been obtained by the reaction between Zn(OAc)2 2H2O, -acetamidocinnamic acid (HACA), and 4-phenylpyridine (4-Phpy) using EtOH as solvent. Its recrystallization in CH3CN or EtOH yields two trinuclear complexes, both having pinwheel arrays with formulas [Zn3( -ACA)6(4-Phpy)2] 4CH3CN (2 4CH3CN) and [Zn3( -ACA)6(EtOH)2] 4EtOH (3 4EtOH), respectively. These trinuclear species, unavoidably lose their solvent co-crystallized molecules at RT yielding the complexes [Zn3( -ACA)6(4-Phpy)2] (2) and [Zn3( -ACA)6(EtOH)2] (3). In addition, compound 2 has also been obtained reacting Zn(OAc)2 2H2O, HACA, and 4-Phpy in a 1:2:2 ratio using CH3CN as solvent. Compounds 1-3 have been characterized by analytical and spectroscopic techniques. Furthermore, single crystals suitable for X-ray di raction method for compounds 1, 2 4CH3CN, and 3 4EtOH were obtained and their supramolecular interactions have been studied and discussed, showing 2D supramolecular planes for the trinuclear complexes and a 3D supramolecular network for the coordination polymer. Finally, the supramolecular interactions of 2 4CH3CN and 3 4EtOH have been compared using Hirshfeld surface analysis and electrostatic potential calculations.