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The synthesis of four rhodium(II) paddlewheel complexes bearing axial aromatic amines and coumarin ligands, with formula [Rh2(OAc)4(L)2] (L = NH2Mesityl (1), NH2Dip (2), NH2Couma (3), coumarin (4)), prompted by microwave irradiation, was carried out successfully. All of the complexes were characterized by the melting point, elemental analysis, NMR, IR, and UV/Visible spectroscopy. Additionally, the structure of complexes 1-2 and 4 was corroborated by single-crystal X-ray diffraction. Cyclic voltammetry, ESI-MS, and tandem MS analyses were carried out in compound 1 for gaining further insight into its stability. Finally, a DFT study shows that complexes 1–4 are the thermodynamic products, having as intermediates complexes 1′–4′ which, under our experimental conditions, cannot be isolated. [ABSTRACT FROM AUTHOR]

Abstract: The reaction of LiArMe6 [ArMe6 C6H3-2,6(C6H2-2,4,6-Me3)2] with InCl, [In(InI4)], InCl in the presence of LiI, or ‘GaI’ in toluene solution resulted in the isolation of the 1,2-diaryl-1,2-dihalogen derivatives [{InCl(ArMe6)}2]2 (1), [{InI(ArMe6)}2]2 (2), [{In4Cl2I2(ArMe6)4}] (3), and [{GaI(ArMe6)}2] (4). The indium derivatives 1–3 were isolated as tetrametallic complexes formed via the almost symmetric bridging by four halides of two In–In bonded, ArMe6In–InArMe6 moieties. In 1, the In4Cl4 core features almost parallel In–In units, linked by four almost symmetrically bridging chlorides. This yields a structure formed from two folded In2Cl2 rings, and two six-membered In4Cl2 boat-shaped rings that have common In–Cl edges. The structures of 2 and 3 also feature two ArMe6InInArMe6 units bridged by four halides. However, there is a large torsion angle between the two In–In vectors, so that the In4I4 (2) and In4Cl2I2 (3) cores are formed from four five-membered In3I2 (2) or In3ClI (3) rings. Compound 4 has a simple Ga–Ga bonded dimeric structure, in which the gallium atoms are three coordinated, being bonded to each other as well as to an iodine and an ArMe6 ligand. All the compounds were characterized by 1H and 13C {1H} NMR spectroscopy, and by X-ray crystallography. The structural differences between the gallium and indium derivatives is probably a result of the larger size and greater Lewis acidity of the indium centers. [Copyright &y& Elsevier]