A Series of Vanadogermanates from 1D Chain to 3D Framework Built by Ge-V-O Clusters and Transition-Metal-Complex Bridges

Three novel extended vanadogermanates, {[(en)(2)Cd2Ge8V12O40-(OH)(8)(H2O)][Cd(en)(2)](2)}6H(2)O (1), {[Zn-2(dap)(3)][Zn(dap)](2)Ge6V15O48-(H2O)}[Zn(dap)(2)(H2O)](2)center dot 3H(2)O (2), and {[Cd-3(mu-dien)(2)(Hdien)(2)(H2O)(2)]Ge4V16-O42(OH)(4)(H2O)}center dot 2H(2)O (3; en = ethylenediamine, dap = 1,2-diaminopropane, dien = diethylenetriamine), have been hydrothermally synthesized and structurally characterized by elemental analysis. 1R spectroscopy, powder XRD, thermogravimetric analysis, and single-crystal XRD. Their Ge-V-O cluster anions are derived from the V18O42 cluster shell by replacing VO5 square pyramids with Ge2O7 groups. Compound 1 exhibits a ID sinusoidal chain built up from rare inorganic-organic hybrid dicadmium-substituted vanadogermanate ([Cd(en)](2)V12O40(GeOH)(8-)(H2O)} clusters and [Cd(en)(2).] complexes. Compound 2 is the first example of a 2D network based on linkage of the unusual {Ge6V15O48(H2O)) clusters and two types of Zn complex fragments. Compound 3 is an unprecedented 3D framework built by (Ge4V16O47-(OH)(4)(H2O)) clusters and rare trinuclear bridging complex cations [Cd-3(mu dien),(Hdien)(2)(H2O)(2)](8+) Magnetic measurements illustrate that both 1 and 2 have antiferromagnetic exchange interactions between metal centers, whereas 3 exhibits ferrimagnetic behavior, which is rare in polyoxovanadate complexes.