pH as a Structure Director in the Synthesis of Copper Molybdates

Abstract

This paper deals with the investigation of the reactions of aqueous molybdates in the presence of copper ions under varying pH to obtain new copper molybdates and rationalize the structures formed in terms of the self-assembling nano-building blocks of polyoxomolybdates (POMs). The reactions led to the precipitation of porous copper molybdates: 1D polymeric anions in (NH4)6[{Cu(H2O)4}{Mo36O112(H2O)16}].21H2O, 1, a 3D framework bimetallic oxide in Cu3Mo2O9, 2. Our results reported here clearly suggest that copper complexes formed during the initial stages of the reaction probably dictate the architecture of the final solids. Interestingly the magnetic properties studied on these compounds showed that 1 shows paramagnetic ordering since magnetically active centres i.e. Cu(II) are separated by large diamagnetic centres of {Mo36} cluster anions where as 2 shows the dominance of antiferromagnetic near-neighbor interaction.

Controllable Assembly of MoVI36-Based Polyoxometalate Porous Frameworks with Silver Ions and Lung Cancer Cell-Specific Cytotoxicity

“…To obtain structures with larger pores, transition metals used as linkages have a lot of room for development in forming porous frameworks with {Mo 36 } SBUs. As far as we know, only two cases have been reported. , Silver ions have been attracting to serve as flexible linkers for their softer metallic aspect as well as high affinity to N and O donors . However, the strong interaction between the silver ions and the POM cluster makes their precipitation easier, resulting in difficulty in the crystallization process.…”