Two new Cu(II) m-hydroxybenzoato complexes with chloro- and carboxylato-bridged dinuclear [Cu(µ2−Cl)(µ2−COO)Cu] cores

In aqueous methanolic solution, reactions of CuCl2, m-hydroxybenzoic acid (HL), and NaOH with 2,2'-bipyridine (bpy) and 1,10-phenanthroline (phen) at room temperature afforded {[Cu(bpy)L](µ2−Cl)(µ2−L)[Cu(bpy)L]}⋅1.2H2O (1) and {[Cu(phen)Cl](µ2−Cl)(µ2−L)[Cu(phen)L]} (2) with chloro- and carboxylato-bridged dinuclear [Cu(µ2−Cl)(µ2−COO)Cu] cores. The Cu2 dimers in 1 are pairwise aggregated to form H-bonded tetranuclear motifs, which are extended by H2O into 1-D H-bonded chains and further assembled into 2-D supramolecular networks. The Cu2 dimers in 2 are also linked into 1-D H-bonded chains and further assembled into 2-D supramolecular layers. Magnetic measurements indicate that significant antiferromagnetic interactions (J = −15.9, −12.2 cm−1) between Cu2+ ions are dominant in these dinuclear [Cu(µ2−Cl)(µ2−COO)Cu] cores. To the best of our knowledge, 2, crystallizing in the acentric polar orthorhombic space group Pna21, represents the first example of metal m-hydroxybenzoato complexes with ferroelectric pr...