Research Projects

The impetus for the proposed work is to get an insight about the relationship between structural network of functional Metal-Organic Frameworks (MOFs), designed by combining a well-known inorganic cluster unit with various pre-designed functionalized polycarboxylic acids, and their physiochemical and material properties. The aim is to construct multifunctional MOFs using the node-spacer concept, i.e., metal-clusters as nodes and divergent polycarboxylic acids as linkers. Of particular interest is a common omnipresent inorganic trinuclear triangular Cu-pyrazolate cluster, [Cu3(μ3-OH)(μ-Pyz)3]2+ moiety (TCuP). The discrete TCuP motif is one of the most commonly found clusters when the Cu(II) ion is reacted with 1H-pyrazole and their characteristic structure, magnetic, catalytic or luminescent properties are well documented. The discrete TCuP motif, using an auxiliary divergent polycarboxylic acid, can be grafted inside the infinite MOFs structure. Wherein, the carboxylate groups adopt a bis-monodentate coordination mode and clump two symmetrically equivalent TCuP units and results in a hexanuclear Cu6 (HCuP) core. Interestingly, the reactivity, emanating from local tris-Cu-pyrazolate coordination environment does not wear off as we increase the dimensionality of discrete TCuP unit to polymeric MOFs. Naturally the first but the most crucial step of this proposal is the synthesis and basic characterization along with acquiring structural knowledge from X-ray crystallography of the H/TCuP-based MOFs. Besides the by-default physiochemical properties of the TCuP unit, we aim to synthesize auxiliary polycarboxylic linkers with very specific organic functional groups to introduce additional ligand-specific physiochemical and material properties. The targeted properties to be invoked and optimized utilizing the contribution of strategically designed auxiliary ligands can be summarized as: (I) One of the prime objectives of this proposal is to study magnetic behaviour of pyrazole moiety as superexchange pathways between the metal ions in polymeric networks (II) Synthesis of photoreactive materials fusing the high-nuclearity H/TCuP with organic ligands with grafted chromophores. (III) Study the redox properties of thiazolothiazol based MOFs. (IV) Synthesis of various chiral amino acid based MOFs to study their biocompatibility and biomedical utility. (V) Various reactivity studies related to chirality of the MOFs will also be explored. To conclude, an important aspect of inorganic complex is more-the-merrier nuclearity. Higher nuclear metal clusters are envisaged as the primary reactive sites, yielding various chemical reactivities which are often linked to nuclearity. The proposal aims a simple improvisation of stitching these isolated individual complexes, to reproduce the inherent physiochemical properties of an inorganic complex in a more convenient and often economical polymeric form, while preserving the basic chassis of the complex.