Pradip Kumar Gogoi

Reduced graphene oxide was synthesized and functionalized with FeSO₄⋅7H₂O to form a reduced graphene oxide/iron oxide hybrid composite. The hybrid composite was extensively characterized using various techniques. Its application for transfer hydrogenation of various ketones was studied. The investigation showed that it serves as a good catalyst for transfer hydrogenation of aromatic and some aliphatic ketones resulting in excellent isolated yields (97–99%) of products. It is magnetically separable showing good reusability. The products were characterized and compared with authentic ones.

Transition metal catalyzed hydration of nitriles is an attractive methodology for amide synthesis, and hence recently attracted wide attention. It is one of the significant organic transformations as amides play a vital role in biological, pharmaceutical and industrial applications. In this work, we report the synthesis of a new solid supported Ru (III) Schiff base complex, Ru@imine‐nanoSiO₂immobilized on nanosilica obtained from rice husk. The complex was characterized by FTIR, powder X‐ray diffraction, BET surface area measurement, UV–vis, SEM–EDX, TEM, ESR, X‐ray photoelectron spectroscopy and ICP‐AES analysis. Using Ru@imine‐nanoSiO₂as the catalyst, the hydration of nitriles ini‐PrOH at 40 °C was studied which resulted in good isolated yields (60–99%). The catalyst can be recycled and reused up to 5^thcycle without any loss in activity. The products were characterized by FTIR, GC–MS and¹H‐NMR spectroscopy and compared with authentic samples.

Two series of basic triethylamine bridged pyridinium/imidazolium tricationic ionic liquids were synthesized as viscous liquids by ion‐pairing with hydroxide, acetate and imidazolide as basic anions. The characterization of tricationic ionic liquids was done using ¹ H and ¹³ C NMR, FT‐IR, Thermogravimetric analysis (TGA), Hammett basicity EI‐MS and elemental analysis techniques. Thermal stabilities were found within the range of 100–150 °C for these ionic liquids. They acted as efficient recyclable homogeneous catalysts for the representative Knoevenagel condensation of benzaldehyde and malononitrile at room temperature stirring in neat condition for 10–20 min. The catalytic activity of these ILs was found to be slightly different from each other for the model reaction and did not follow the same sequence of their measured Hammett basicity value.