NOPR Collection:http://nopr.niscpr.res.in/handle/123456789/448822026-10-13T05:07:34Z2026-10-13T05:07:34ZCrystal engineering of molecular to nonmolecular metal malonates in presence of piperazine: Role of metal ions in tuning architecturesMote, Kaustubh RThomas, JencyRamanan, Arunachalamhttp://nopr.niscpr.res.in/handle/123456789/448932018-08-23T06:31:45Z2018-08-01T00:00:00ZTitle: Crystal engineering of molecular to nonmolecular metal malonates in presence of piperazine: Role of metal ions in tuning architectures
Authors: Mote, Kaustubh R; Thomas, Jency; Ramanan, Arunachalam
Abstract: Growth of transition metal malonate (mal) based solids from aqueous solution is investigated in the presence of piperazine (pip). Reaction under ambient conditions favored the growth of [{M(mal)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>}{H<sub>2</sub>pip}] (M: Ni, <strong>1</strong>; M: Co, <strong>2</strong>), [{Cu(mal)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>}{H<sub>2</sub>pip}].2H<sub>2</sub>O (<strong>3</strong>), and, [Zn(mal)(pip)(H<sub>2</sub>O)] (<strong>4</strong>). While <strong>1-3</strong> are molecular solids, <strong>4 </strong>is a 2-D coordination polymer. In the case of cobalt, higher acidic condition favored the formation of a molecular organic-inorganic salt, [(H<sub>2</sub>pip){CoCl<sub>4</sub>}] (<strong>5</strong>). The same reaction under a different crystallization condition, i.e., lesser polar solvent and slightly higher temperature (solvothermal) led to a 2-D coordination polymer [{Co(mal)(H<sub>2</sub>O)(Hpip)}]Cl (<strong>6</strong>). A retrosynthesis approach has been employed to interpret the crystallization reaction and compare the supramolecular reactivity of aggregating metal tectons in engineering the molecules to form either a molecular solid or coordination polymer.
Page(s): 1081-10902018-08-01T00:00:00ZCatechin mediated one-step fabrication of ZnO microspheres: Synthesis, characterization and applicationsDas, SomnathPramanik, Amitavahttp://nopr.niscpr.res.in/handle/123456789/448922018-08-23T06:23:42Z2018-08-01T00:00:00ZTitle: Catechin mediated one-step fabrication of ZnO microspheres: Synthesis, characterization and applications
Authors: Das, Somnath; Pramanik, Amitava
Abstract: A one-step template-free synthesis of hollow ZnO microspheres has been developed by a hydrothermal route in the presence of (+)-catechin as crystal habit modifier. Morphology evolution of ZnO particles shows the transformation from hexagonal rods to microspheres with increase in the concentration of catechin in the reaction medium. The microspheres are formed by the aggregation of fine grained nano-sized ZnO particles. The synthesized particles show enhanced photocatalytic ability and high potency as a drug delivery agent.
Page(s): 1091-10992018-08-01T00:00:00ZElectrochemical impedance spectroscopy study of oxygen evolution reaction on nanosized CoWO<sub>4</sub> and NiWO<sub>4</sub>Srirapu, V K V PKumar, AjayKumari, NirmalaSingh, Ravindra Nathhttp://nopr.niscpr.res.in/handle/123456789/448912018-08-23T06:21:42Z2018-08-01T00:00:00ZTitle: Electrochemical impedance spectroscopy study of oxygen evolution reaction on nanosized CoWO<sub>4</sub> and NiWO<sub>4</sub>
Authors: Srirapu, V K V P; Kumar, Ajay; Kumari, Nirmala; Singh, Ravindra Nath
Abstract: CoWO<sub>4</sub> and NiWO<sub>4</sub> have been prepared by a co-precipitation method and investigated as electrocatalysts for the oxygen evolution reaction in 1 M KOH by electrochemical impedance spectroscopy. The electrode kinetic parameters such as the electrochemical active surface area, exchange current density, Tafel slope, and the reaction order are determined. Results have shown that the values of the Tafel slope and reaction order obtained from the EIS study excellently match with those determined by dc techniques.
Page(s): 1100-11052018-08-01T00:00:00ZEpoxidation of styrene over MgO-rice derived carbon composite catalyst prepared by <em>in situ</em> transformation techniqueKalpana, MSankar, E SivaReddy, K SaiduluRao, K S RamaSwathi, JKumar, V VijayNaresh, GVenugopal, Ahttp://nopr.niscpr.res.in/handle/123456789/448902018-08-23T06:15:08Z2018-08-01T00:00:00ZTitle: Epoxidation of styrene over MgO-rice derived carbon composite catalyst prepared by <em>in situ</em> transformation technique
Authors: Kalpana, M; Sankar, E Siva; Reddy, K Saidulu; Rao, K S Rama; Swathi, J; Kumar, V Vijay; Naresh, G; Venugopal, A
Abstract: With a view to develop eco-friendly and metal-free catalysts, herein we report MgO-rice derived carbon composite for epoxidation of styrene to styrene epoxide. MgO-C catalysts prepared via <em>in situ</em> transformation technique are characterized by powder XRD, BET-surface area, Raman spectroscopy, CO<sub>2</sub>-TPD, CHNS analysis and TGA techniques. Under optimized reaction conditions, MgO-C0.5 catalyst efficiently catalyzed the reaction with 84% conversion of styrene yielding 82% selectivity to styrene epoxide. The characterization results suggest that the catalytic activity is attributed to the presence of well dispersed accessible basic sites obtained through <em>in situ</em> dispersion of MgO over rice derived carbon. MgO-C0.5 catalyst is recyclable up to four cycles without significant loss in the activity and selectivity.
Page(s): 1106-11112018-08-01T00:00:00Z