Abstract

We introduce two novel one-dimensional coordination polymers (CPs) with helical arrangements based on copper(II) and an achiral Schiff base ligand, [Cu(L)(DMF)(X)](n) (X = NO3- (1) and Cl- (2)), where L = 2-{[(pyridin-3-yl)imino]methyl}phenol. Both structures crystallize in an orthorhombic unit cell with a P2(1)2(1)2(1) space group. In both compounds, unconventional noncovalent interactions are fundamental for the structural features, modulating the dihedral angle ca. 70 degrees between the two aromatic rings that are part of the organic ligand. Magnetic measurements indicate that weak antiferromagnetic interactions predominate in both CPs, with a J value of -3.34 cm(-1) for 1 and -4.95 cm(-1) for 2, corroborated by ab initio first-principles calculations. Furthermore, electronic structure analyses reveal a semiconductor behavior for both CPs. First-principles calculations predict small polaron localization around the Cu sites, with a higher formation of electron polarons in compound 1 than in 2.