First Organic–Inorganic Hybrid Compounds Formed by Ge-V-O Clusters and Transition Metal Complexes of Aromatic Organic Ligands

Three compounds based on Ge-V-O clusters were hydrothermally synthesized and characterized by IR, UV-Vis, XRD, ESR, elemental analysis and X-ray crystal structural analysis. Both [Cd(phen)(en)](2)[Cd(2)(phen)(2)V(12)O(40)Ge(8)(OH)(8)(H(2)O)]∙12.5H(2)O (1) and [Cd(DETA)](2)[Cd(DETA)(2)](0.5)[Cd(2)(phen)(2)V(12)O(41)Ge(8)(OH)(7)(0.5H(2)O)]∙7.5H(2)O (2) (1,10-phen = 1,10-phenanthroline, en = ethylenediamine, DETA = diethylenetriamine) are the first Ge-V-O cluster compounds containing aromatic organic ligands. Compound 1 is the first dimer of Ge-V-O clusters, which is linked by a double bridge of two [Cd(phen)(en)](2+). Compound 2 exhibits an unprecedented 1-D chain structure formed by Ge-V-O clusters and [Cd(2)(DETA)(2)](4+) transition metal complexes (TMCs). [Cd(en)(3)]{[Cd(η(2)-en)(2)](3)[Cd(η(2)-en)(η(2)-μ(2)-en)(η(2)-en)Cd][Ge(6)V(15)O(48)(H(2)O)]}∙5.5H(2)O (3) is a novel 3-D structure which is constructed from [Ge(6)V(15)O(48)(H(2)O)](12−) and four different types of TMCs. We also synthesized [Zn(2)(enMe)(3)][Zn(enMe)](2)[Zn(enMe)(2)(H(2)O)](2)[Ge(6)V(15)O(48)(H(2)O)]∙3H(2)O (4) and [Cd(en)(2)](2){H(8)[Cd(en)](2)Ge(8)V(12)O(48)(H(2)O)}∙6H(2)O (5) (enMe = 1,2-propanediamine), which have been reported previously. In addition, the catalytic properties of these five compounds for styrene epoxidation have been assessed.