Ammonia Oxidation Enhanced by Photopotential Generated by Plasmonic Excitation of a Bimetallic Electrocatalyst

We study how visible light influences the activity of an electrocatalyst composed of Au and Pt nanoparticles. The bimetallic composition imparts a dual functionality: the Pt component catalyzes the electrochemical oxidation of ammonia to liberate hydrogen and the Au component absorbs visible light by the excitation of localized surface plasmon resonances. Under visible-light excitation, this catalyst exhibits enhanced electrochemical ammonia oxidation kinetics, outperforming previously reported electrochemical schemes. We trace the enhancement to a photochemical potential resulting from electron–hole carriers generated in the electrocatalyst by plasmonic excitation. The photopotential responsible for enhanced kinetics scales linearly with the light intensity—a general design principle for eliciting superlative photoelectrochemical performance from catalysts comprised of plasmonic metals or hybrids. We also determine a photochemical conversion coefficient.     

Development and Validation of a High-Performance Thin-Layer Chromatographic Method for the Simultaneous Estimation of Torsemide and Eplerenone by Quality by Design Approach

JPC – Journal of Planar Chromatography – Modern TLC - This paper includes the development of a novel, systematic, quality by design (QbD)-based high-performance thin-layer...     

Facile access to polymer supported zinc–salen complex: highly efficient heterogeneous catalyst for synthesizing hydantoins,thiohydantoins and Schiff bases in aqueous medium

Research on Chemical Intermediates - The synthesis of polymer supported zinc–salen complex (PS-Zn–salen) is described. The mononuclear zinc(II)–salen complex was characterized by...     

1,3-Dipolar cycloaddition of chalcones and arylidene-1,3-dicarbonyls with diazosulfone for the regioselective synthesis of functionalized pyrazoles and pyrazolines

A convenient method for the synthesis of 3-acylpyrazoles and pyrazole-3-carboxylates using diazosulfone as a reactive 1,3-dipole and a diazomethane equivalent is reported here. Chalcones, arylidenemalonates and other arylidene-1,3-dicarbonyls performed well as the dipolarophiles in the reaction with the diazosulfone which took place under simple base mediated conditions (Cs₂CO₃ or NaOEt in EtOH). In few cases, the initial cycloadducts, the intermediate pyrazoline derivatives, could also be isolated and characterized. The pyrazoline derivatives undergo an alkoxide mediated 1,4-elimination, viz. decarboxylation-detosylation to afford the pyrazole derivatives.     

Tris-hydroxymethylaminomethane (THAM): An efficient organocatalyst in diversity-oriented and environmentally benign synthesis of spirochromenes

Tris-hydroxymethylaminomethane has been demonstrated to be an efficient organocatalyst in diversity-oriented synthesis of medicinally prevalent spirochromenes by one-pot, three-component reactions between isatins, malononitrile, and enolizable CH acids like dimedone, 4-hydroxycoumarin, 4-hydroxy-N-methylquinolin-2-one, or in situ generated 2-methylpyrazolon-2-one. Biodegradability and extremely low cost of the catalyst are the noteworthy features of this chromatography-free protocol.     

Heat of fusion and excess thermodynamic functions of organic eutectics

Phase diagrams and heats of fusion of some organic eutectics have been studied. An empirical equation is proposed for the determination of heats of fusion of eutectics. Excess thermodynamic functions such as h^E, S^E and g^E have been calculated. The heats of fusion of various organic eutectics have been compared with values obtained from the mixture law. The results have been explained on the basis of the fact that clusters are formed during melting. The cluster formation tendency is greater in systems in which hydroxyl groups are present.     

Copper nanoparticles in an ionic liquid: an efficient catalyst for the synthesis of bis-(4-hydroxy-2-oxothiazolyl)methanes

Copper nanoparticles were synthesized and characterized by TEM, XRD and UV-vis techniques. The copper nanoparticles in an ionic liquid were employed as a recyclable catalyst for the synthesis of bis-(4-hydroxy-2-oxothiazolyl)methanes in excellent yields and in short reaction times.     

Infrared-optical double-resonance measurements on O-H...H-Ge dihydrogen-bonded phenol-triethylgermanium hydride complex in the gas phase

Spectroscopic investigation of a dihydrogen-bonded complex between phenol and triethylgermanium hydride is reported here. Laser-induced fluorescence excitation, fluorescence-detected infrared, and IR-UV hole-burning spectroscopic studies were carried out in supersonic jet to investigate the complex formation between phenol and triethylgermanium hydride. The lowering of the O-H stretching frequency of the phenol moiety in the complex with triethylgermanium hydride clearly establishes the role of phenol as hydrogen bond donor. The experimental results together with the ab-initio calculations unambiguously confirm formation of an O-H...H-Ge dihydrogen-bonded complex between phenol and triethylgermanium hydride.