[Show abstract][Hide abstract] ABSTRACT: A germanium–vanadate cluster [Ge5V6O21(heda)6] (1) with covalently coordinated N-(2-hydroxyethyl)ethylenediamine (Hheda) was synthesized and crystallographically characterized. The cluster is a new type of GeVO cluster, in which there coexists various oxo-polyhedra of VIV and GeIV, octahedral VO6, VO5N, and GeO4N2, VO5 pyramid and GeO4 tetrahedron. The cluster is also an unusual neutral germanium–polyoxovanadate. The deprotonated hydroxyl group and part of the amine groups of the heda ligand covalently coordinate to the cluster. There are three coordination modes of the ligand, monodentate, chelating and multi-chelating modes. The organic ligand plays important roles in the charge balance and cluster construction.
[Show abstract][Hide abstract] ABSTRACT: Two titanium-oxo-clusters Ti(6)O(4)(o-BDC)(2)(o-BDC(i)Pr)(2)(O(i)Pr)(10) (1) and Ti(6)O(3)(o-BDC)(2)(O(i)Pr)(14) (2) (BDC = benzene dicarboxylate) were prepared by one-step in situ solvothermal synthesis. The compounds are the rare examples of the dicarboxylate-substituted titanium-oxo-clusters. Their crystal structures are successfully measured by single-crystal X-ray analysis. The Ti(6) oxo-clusters of 1 and 2 are constructed by two dual corner-missing cube subunit, Ti(3)O(3). The two subunits are linked by double μ(3)-O bridges for 1 and single μ(2)-O bridge for 2, respectively, and the latter is a new type of carboxylate substituted titanium-oxo-cluster. A photochromic effect was observed upon irradiation of the crystals in the presence of alcohol. The light irradiation changed the color of the crystals from transparent to purple-gray. The Ti(III) signal was detected after the irradiation, and when the sample was exposured in air, superoxide diatomic O(2)(•-) radical was found. Photodegradation of the methyl orange in aqueous dispersions of microcrystals of the cluster 2 was carried out under UV cut white light with the assistance of H(2)O(2).
[Show abstract][Hide abstract] ABSTRACT: A Ge(7) germanate, [Ni(H(2)O)(μ-C(2)H(6)NO)(2)Ge(7)O(14)(C(2)H(7)NO)]·C(2)H(5)OH (1), was prepared by the solvothermal method using ethanolamine (C(2)H(7)NO) as solvent, ligand, and structure-directing agent. Compound 1 shows an unusual GeO framework fused with transition metal complex. The 2-D layers of Ge(7) clusters are linked by a [Ni(H(2)O)(μ-C(2)H(6)NO)(2)] moiety, forming a 3-D architecture. The preparation and structure of 1 are discussed in comparison with the Ge(9) germanates decorated with metal ethylenediamine complexes. The hydroxyl group of the ethanolamine plays an important role in formation of the 3-D structure, in which the ligand ethanolamine is coordinated directly onto the Ge cluster by the hydroxyl group. It is a new type of germanates incorporated with a TM complex bridge. The proton on the flexible amine side can be exchanged by alkali metal ions.