Room-temperature magnetic liquid complexes of 2-hexyldecanoato ligand with Cu(II), Ni(II) and Co(II) ions

Abstract

Three new complexes [Cu2(L)4(LH)2] (1), [Ni2(L)4(EtOH)2(H2O) 2].H2O.CHCl3 (2) and [Co2(L) 4(H2O)4].3H2O (3), were obtained as coloured viscous liquids at room temperature (30 °C) and in good yields from the reaction of sodium 2-hexyldecanoate (NaL) with the corresponding MCl 2 (M = Cu, Ni or Co). The structural formulae of these complexes were indirectly deduced by a combination of analytical results and additionally for 1, inferred from that of [Cu2(CH3(CH2) 5COO)4] (4) obtained as single crystals under similar synthetic conditions. Complexes 1-3 were paramagnetic with weak antiferromagnetic interactions between the two M(II) centres, while 4 has a significantly stronger antiferromagnetic interaction. Complex 3 was also high spin. These complexes were thermally stable: 1 and 2 decomposed at 200 °C, 3 at 150 °C and 4 at 280 °C. However, they were redox inactive in the potential range -1.5 V to + 1.5 V, while only 1 was mesogenic with a hexagonal columnar mesophase (Colh) at -23.2 °C.