An insight into the molecular structures, theoretical calculation and catalytic activities of novel heterotrinuclear [CuII2CeIII] and heterohexanuclear [CuII4YIII2] bis(salamo)-based complexes

Two heteropolynuclear complexes, [CuII2CeIII] [Cu2(L)Ce(NO3)3] and [{Cu2(L)Y(NO3)2(μ-AcO)}{Cu2(L)Y(NO3)2(μ-NO3)(CH3OH)}]·4CH3OH, were synthesized. It was found that only the [CuII2CeIII] complex showed high catecholase and benzoxazinone synthase like catalytic activity.

The crystal structures of {LnCu5}3+ (Ln = Gd, Dy and Ho) 15-metallacrown-5 complexes and a reevaluation of the isotypic EuIII analogue

Three new isotypic heteropolynuclear complexes, namely pentaaquacarbonatopentakis(glycinehydroxamato)nitratopentacopper(II)lanthanide(III) x-hydrate, [LnCu5(GlyHA)5(CO3)(NO3)(H2O)5]·xH2O (GlyHA2− is glycinehydroxamate, N-hydroxyglycinamidate or aminoacetohydroxamate, C2H4N2O2 2−), with lanthanide(III) (Ln III) = gadolinium (Gd, 1, x = 3.5), dysprosium (Dy, 2, x = 3.28) and holmium (Ho, 3, x = 3.445), within a 15-metallacrown-5 class were obtained on reaction of lanthanide(III) nitrate, copper(II) acetate and sodium glycinehydroxamate. Complexes 1–3 contain five copper(II) ions and five bridging GlyHA2− anions, forming a [CuGlyHA]5 metallamacrocyclic core. The Ln III ions are coordinated to the metallamacrocycle through five O-donor hydroxamates. The electroneutrality of complexes 1–3 is achieved by a bidentate carbonate anion coordinated to the Ln III ion and a monodentate nitrate anion coordinated apically to one of the copper(II) ions of the metallamacrocycle. The lattice parameters of complexes 1–3 are similar to those previously reported for an EuIII–CuII 15-metallacrown-5 complex with glycinehydroxamate of proposed composition [EuCu5(GlyHA)5(OH)(NO3)2(H2O)4]·3.5H2O [Stemmler et al. (1999). Inorg. Chem. 38, 2807–2817]. High-quality X-ray data obtained for 1–3 have allowed a re-evaluation of the X-ray data solution proposed earlier for the EuCu5 complex and suggest that the formula is actually [EuCu5(GlyHA)5(CO3)(NO3)(H2O)5]·3.5H2O.

Stepwise synthesis of mixed-metal assemblies using pre-formed Ru(ii) ‘complex ligands’ as building blocks

A stepwise approach to assembly of heteropolynuclear complexes is reported, including a Ru4Co4 cubic cage which encapsulates a {Na(BF4)4}3− complex anion.