Sourav De

Research Centre for Natural Sciences, Hungarian Academy of Sciences · Chemical Crystallography Research Laboratory

Five unusual meroterpenoids based on new carbon skeletons, pauciflorins A-E (1-5), were isolated by multistep chromatographic separations of a methanol extract of the aerial parts of Centrapalus pauciflorus. Compounds 1-3 are derived by the connection of a 2-nor-chromone and a monoterpene unit, whereas 4 and 5 are dihydrochromone-monoterpene adduct...

Crystal structures of diastereomeric salt pairs, as well as double salts are rare to find in the literature [1, 2]. Present work involves the crystallization and structural elucidation of two constitutional isomer double salts along with their related diastereomeric salt pairs. The investigated systems are 1-cyclohexylethylammonium 2-chloromandelat...

The number of crystal structures of diastereomeric salt pairs and especially of double salts is limited in the literature. This work exceptionally presents the structures of two constitutional isomer double salts along with their related diastereomeric salt pairs, which were successfully crystallized and their structures elucidated presenting two c...

Background: Bio-inorganic nanoparticles or metal nanoparticles are used in medicine for diagnostic and treatment purposes. The nanomedicines from traditional Ayurvedic system are termed as bhasma. Rasashastra, the branch of inorganic medicines of Ayurveda, has documented monographs of metal-mineral bhasmas as potent drugs. However there is lack of...

The crystal structure of the title compound, C 16 H 26 N 4 O 6 S 2 ·2H 2 O, a water-soluble di- N -heterocyclic carbene ligand precursor was determined using a single crystal grown by the slow cooling of a hot N , N -dimethylformamide solution of the compound. The dihydrate crystallizes in the monoclinic space group P 2 1 / c , with half of the zwi...

An environment-friendly, convenient, fast and solvent-free mechanochemical approach have been accomplished for the synthesis of several diimidazolium salts and the bridging dinuclear rhodium(I)–N-heterocyclic carbene complexes of the type [{RhCl(cod)}2(μ-di-NHC)] derived from them. The compounds were synthesized also by the classical solvent method...

Synthesis of several new N-heterocyclic carbene ligands and their transition metal complexes are reported both in traditional solvent methods and in a ball mill without the use of any solvents. Successful catalytic applications of those complexes are also described.

A new synthetic method for obtaining [RhCl(cod)(NHC)] complexes (1–4) (cod = η4-1,5-cyclooctadiene, NHC = N-heterocyclic carbene: IMes, SIMes, IPr, and SIPr, respectively) is reported together with the catalytic properties of 1–4 in nitrile hydration. In addition to the characterization of 1–4 in solution by 13C NMR spectroscopy, the structures of...

The discovery and development of N-heterocyclic carbenes is no doubt one of the biggest success stories in the era of modern chemistry. In the last three decades, poly-N-heterocyclic carbenes have received increasing attention and a large number of reports have been published on the use of poly-NHC complexes in water. This paper is aimed to provide...

N-heterocyclic carbenes (NHC) rank amongst the most powerful tools in today's chemistry because of their considerable potential and scope in coordination/organometallic chemistry, catalysis, and materials science.[1-4] The aim of my work was to prepare unique NHC metal catalysts for water-related applications. Synthesis of several chelating and bri...

N-heterocyclic carbenes rank amongst the most powerful tools in today’s chemistry because of their considerable potential and scope in coordination/organometallic chemistry, catalysis, and materials science. The main aim of my work is to synthesize unique water-soluble chelating bidentate NHC metal catalysts. Synthesis of several (CH2)n –linked bis...

A recent “Renaissance” has various fields of chemistry exploring processes that are more Earth-friendly One focus is to make kinetic experiments greener by applying modified methodologies for metal mediated oxidation kinetics mean while recycling the used reagents and catalysts after completion in greener aqueous media. Use of surfactants has been...

Chromic acid oxidation of malonic acid in aqueous media has been investigated spectrophotometrically at 303 K. The product glyoxylic acid has been characterized by 13C-NMR and FTIR spectroscopy. Three representative N-heteroaromatic nitrogen base promoters, 2-picolinic acid, 2,2′-bipyridine (bpy) and 1,10-phenanthroline, in combination with the ani...

Review: properties, advantages and drawbacks, production, characterization and applications; 84 refs.

Natural surfactants or biosurfactants are amphiphilic biological compounds, usually extracellular, produced by a variety of microorganisms from various substances including waste materials. There is increasing interest on this topic because of their unique properties such as low toxicity, functionality under extreme conditions, based on renewable s...