Novel copper(II) sulfonate–arsonates with discrete cluster, 1D chain and layered structures

Hydrothermal reactions of copper(II) salts with o-sulfophenylarsonic acid (o-HO3S–C6H4–AsO3H2, H3L) led to a layered compound, Cu2.5(L)(OH)2 (1). Introduction of the auxiliary chelating ligands such as 2,2′-bipyridine (bipy) or 1,10-phenanthroline (phen) and 2,2′:6′,2′′-terpyridine (terpy) led to three new copper(II) sulfonate–arsonates with lower dimensional structures, namely, mononuclear Cu(HL)(bipy)(H2O)·2H2O (2), dinuclear [Cu(HL)(phen)]2·4H2O (3) and one-dimensional Cu(HL)(terpy)·2H2O (4). Magnetic property measurements indicate that 1 exhibits ordinary antiferromagnetic feature, without the geometric spin frustration as expected. 2 shows a typical paramagnetic behavior. There exists antiferromagnetic interactions between the magnetic centers in dimeric 3. 4 displays an antiferromagnetic magnetic exchange interaction propagated via OSO bridges.