Synthesis and molecular structure of the first binuclear {(bis-N-isophthaloyl ureato)copper(II)pyridine}2 complex derived from the {(bis-N-isophthaloyl-selenoureato)copper(II)}2 complex by O for Se atom exchange

The bipodal ligand 3,3,3′,3′-tetraethyl-1,1′-isophthaloyl-bis(selenourea) (H2L1) forms a 2:2 copper(II) complex [Cu2(L1)2] , the crystal and molecular structure and EPR spectrum of which are reported. Treatment of [Cu2(L1)2] with excess pyridine results in the formation of a novel (bis-N-acylureato)copper(II) 1:2 pyridine adduct [Cu2(L2)2(py)2], characterized by single crystal X-ray diffraction and EPR spectroscopy, as a consequence of facile Se replacement by O presumably due to hydrolysis of water present in the mixture. The latter complex forms a one-dimensional supramolecular architecture in the solid state, stabilized via π-stacking interactions between alternate Cu-coordinated pyridine molecules.