Optimal entropic uncertainty relation for successive measurements in quantum information theory

We derive an optimal bound on the sum of entropic uncertainties of two or more observables when they are sequentially measured on the same ensemble of systems. This optimal bound is shown to be greater than or equal to the bounds derived in the literature on the sum of entropie uncertainties of two observables which are measured on distinct but identically prepared ensembles of systems. In the case of a two-dimensional Hilbert space, the optimum bound for successive measurements of two-spin components, is seen to be strictly greater than the optimal bound for the case when they are measured on distinct ensembles, except when the spin components are mutually parallel or perpendicular     

Reaction of N-(2-hydroxyethyl) ethylenediamine over zeolite and chromite catalysts

N-(2-hydroxyethyl) ethylenediamine reaction was observed over zeolite catalysts giving rise to only dehydrocyclization and over chromite catalysts showing dehydrocyclization together with dehydrogenation. The major product changes from the cyclized compound piperazine to pyrazine when the reactant is switched from zeolite to chromite catalyst. This process stands as a model reaction for characterizing lone acid sites and adjacent acid-base sites over zeolite and chromite catalysts, respectively.IICT Communication No. 3175     

Gold nanoparticle networks with photoresponsive interparticle spacings

Photoresponsive gold nanoparticle networks were prepared by functionalizing them with azobenzene derivatives. A network can be formed when a linker molecule constituting the azobenzene moiety suitably derivatized on either side with gold surface sensitive groups such as thiols and amines is added to the nanoparticle solution. It is shown that the interparticle spacing in the networks could be controlled by the reversible trans-cis isomerization of the azobenzene moiety induced by UV and visible light, respectively. The photoinduced variation in the interparticle spacings is inferred by the changes in the optical spectra of the gold nanoparticles which display a red or blue shift in the surface plasmon resonance peak depending on a decrease or increase in the interparticle spacing, respectively. Transmission electron microscopy images are in consonance with the evidence from the optical spectra.     

Biomimetic reduction of nimesulide with NaBH4 catalyzed by metalloporphyrins

The biomimetic reduction of anti-inflammatory drug, nimesulide (1) with sodium borohydride catalyzed by 5,10,15,20-tetraarylporphyrinatoiron(III) chlorides [TAPFe(III)Cl] has been studied in organic solvents under anaerobic and aerobic conditions.     

Ring expansion approach for the synthesis of the (3S,4S)-hexahydroazepine core of balanol and ophiocordin

A new and efficient formal total synthesis of (3S,4S)-balanol, a potent protein kinase C inhibitor, was accomplished from tri-O-acetyl-d-glucal. Balanol and ophiocordin consists of a chiral hexahydro azepine-containing fragment and a benzophenone fragment. The azepine core was prepared in chiral form through intramolecular aza Wittig reaction. A triphenylphosphine mediated ring expansion process was employed to form the seven-membered nitrogen heterocycle. The aldehyde equivalent key intermediate was treated with triphenylphosphine to give the azepine core. To demonstrate the applicability of the new route, a synthesis of the balanol is described.     

A hybrid foldamer with unique architecture from conformationally constrained aliphatic-aromatic amino acid conjugate

In this paper, we describe the design and synthesis of a novel hybrid foldamer, derived from a conformationally constrained aliphatic-aromatic amino acid conjugate that adopts a well-defined, compact, three-dimensional structure, governed by a combined conformational restriction imposed by the individual amino acids from which the foldamer is composed. Conformational investigations confirmed the prevalence of a unique doubly bent conformation for the foldamer, in both solid and solution states, as evidenced from single crystal X-ray and 2D NOESY studies, respectively. The findings suggest that constrained aliphatic-aromatic amino acid conjugates offer new avenues for the de novo design of hybrid foldamers with distinctive structural architectures. Furthermore, the de novo design strategy disclosed herein has the potential for significantly augmenting the ‘tool-box’ of the modern day peptidomimetic chemist, as well as providing a novel approach to the field of rational design.     

Reactions of oxiranes with alkali metals: intermediacy of radical-anions

Reaction of oxiranes with alkali metals in aprotic solvents yields a variety of products depending on the nature of the metal and the structure of the oxirane. Deoxygenation to olefins is the major reaction in case of lithium. Rearrangement to carbonyl compounds, reduction to alcohols and formation of dimeric products occur when oxiranes are treated with sodium. All the reactions could be rationalised by a mechanism involving an initial single electron transfer leading to the formation of a radical-anion intermediate.