You are here:
Greener Synthesis of Organics and Nanomaterials: Sustainable Applications of Nano-Catalysts
Citation:
VARMA, R. S. Greener Synthesis of Organics and Nanomaterials: Sustainable Applications of Nano-Catalysts. Presented at Delhi University under the auspices of the Royal Society of Chemistry, North India Section, Delhi, INDIA, August 06, 2010.
Impact/Purpose:
To inform the public.
Description:
The presentation summarizes our recent activity in chemical synthesis involving benign alternatives, such as the use of supported reagents, and greener reaction medium in aqueous or solvent-free conditions.1 The synthesis of heterocyclic compounds, coupling reactions, and a variety of name reactions2 are the primary beneficiaries as exemplified by the synthesis of N-aryl azacycloalkanes, isoindoles, and dihydropyrazoles, 1,3,4-oxadiazoles, 1,3,4-thiadiazoles, 1,3-dioxanes, pyrazoles, catalyzed by basic water or polystyrene sulfonic acid (PSSA) in conjunction with microwave (MW) irradiation.2 Vitamins B1, B2, C, and tea and wine polyphenols which function both as reducing and capping agents, provide extremely simple, one-pot, green synthetic methods to bulk quantities of nanomaterials in water.3a Shape-controlled synthesis of noble nanostructures via MW-assisted spontaneous reduction of noble metal salts using sugars will be presented.3b A general method has been developed for the cross-linking reaction of poly (vinyl alcohol) (PVA) with metallic systems; bimetallic systems,3c and SWNT, MWNT, and C-60.3d The strategy is extended to the formation of biodegradable carboxymethylcellulose (CMC) composite films with noble nanometals;3e such metal decoration and alignment of carbon nanotubes in CMC is possible using MW approach3f which also enables the shape-controlled bulk synthesis of Ag and Fe nanorods in poly (ethylene glycol).3g MW hydrothermal process delivers magnetic nanoferrites4 and micro-pine structured catalysts are obtainable in water from readily available metal salts.5 Sustainable route to nano particles using polyphenols from winery waste,6 their applications in catalysis,7,8 toxicity9 and environmental remediation10 will be highlighted.