02972nas a2200253 4500008004100000022001400041245012000055210006900175260011000244300001400354490000600368520200200374100001602376700002202392700001802414700002102432700002202453700002002475700002002495700002102515700003202536700002202568856012802590 2012 eng d a1744-683X00aCompetition between gelation and crystallisation of a peculiar multicomponent liquid system based on ammonium salts0 aCompetition between gelation and crystallisation of a peculiar m aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcFEB a3446-34560 v83 a

An exemplar competition between gelation and crystallisation phenomena was examined with an unusual synergistic multicomponent (organo) gelator solution (MGS), which consists of a well-defined methanolic solution of (1R, 2R)-1,2-diaminocyclohexane L-tartrate containing 2.4 equiv. of concentrated hydrochloric acid. The optimal composition of the MGS was determined through meticulous solubility, gelation and structural studies, which support a transient gelation mechanism based on the kinetic self-assembly of the tartrate salt driven by hydrogen-bonding interactions, involving ammonium nitrogen donors and hydroxyl oxygen acceptors, and electrostatic interactions. The hydrochloric acid is involved in the solubilisation of the salt through an ionic dissociation-exchange process, which ends up with the formation-precipitation of (1R, 2R)-1,2-diaminocyclohexane dihydrochloride. As a consequence, an irreversible destruction of the gel takes place, which indicates the metastable nature of this phase that cannot be accessed from the thermodynamically equilibrated state. Gelation of a variety of oxygenated and nitrogenated solvents with moderate polarity occurred efficiently using extremely low MGS concentrations at low temperatures, and the gel phase was confirmed by dynamic rheological measurements. Several features make the described MGS unique: (1) it is a multicomponent solution where each component and its stoichiometry play a key role in the reproducible formation and stabilization of the gels; (2) it is formed by simple, small, and commercially available chiral building blocks (dissolved in a well-defined solvent system), which are easily amenable for further modifications; (3) the gelation phenomenon takes place efficiently at low temperature upon warming up the isotropic solution, conversely to the typical gel preparation protocol; and (4) the formed organogels are not thermoreversible despite the non-covalent interactions that characterize the 3D-network.

1 aKapoor, Iti1 aSchoen, Eva-Maria1 aBachl, Jurgen1 aKuehbeck, Dennis1 aCativiela, Carlos1 aSaha, Subhadeep1 aBanerjee, Rahul1 aRoelens, Stefano1 aMarrero-Tellado, Jose, Juan1 aDiaz, David, Diaz uhttps://library.ncl.res.in/content/competition-between-gelation-and-crystallisation-peculiar-multicomponent-liquid-system-000742nas a2200169 4500008004100000022001400041245011000055210006900165260008600234300001200320490000800332520004600340100001800386700002000404700002200424856012600446 2012 eng d a1433-726600aCrystal structure of (2S, 4R)-2-benzyl 1-tert-butyl 4-(tosyloxy)pyrrolidine-1,2-dicarboxylate, C24H29NO7S0 aCrystal structure of 2S 4R2benzyl 1tertbutyl 4tosyloxypyrrolidin aLEKTORAT MINT, POSTFACH 80 13 60, D-81613 MUNICH, GERMANYbOLDENBOURG VERLAGcSEP a361-3620 v2273 a

{C24H29NO7S, triclinic, P1 (no. 1)

1 aGhosh, Munmun1 aMallick, Arijit1 aDiaz, David, Diaz uhttps://library.ncl.res.in/content/crystal-structure-2s-4r-2-benzyl-1-tert-butyl-4-tosyloxypyrrolidine-12-dicarboxylate-001838nas a2200265 4500008004100000022001400041245007400055210006900129260008600198300001400284490000600298520092700304653001701231653003301248653001201281653001901293653001201312100002101324700002401345700002201369700002201391700002901413700002201442856010801464 2013 eng d a1860-539700aC-C Bond formation catalyzed by natural gelatin and collagen proteins0 aCC Bond formation catalyzed by natural gelatin and collagen prot aTRAKEHNER STRASSE 7-9, FRANKFURT AM MAIN, 60487, GERMANYbBEILSTEIN-INSTITUTcJUN a1111-11180 v93 a

The activity of gelatin and collagen proteins towards C-C bond formation via Henry (nitroaldol) reaction between aldehydes and nitroalkanes is demonstrated for the first time. Among other variables, protein source, physical state and chemical modification influence product yield and kinetics, affording the nitroaldol products in both aqueous and organic media under mild conditions. Significantly, the scale-up of the process between 4-nitrobenzaldehyde and nitromethane is successfully achieved at 1 g scale and in good yield. A comparative kinetic study with other biocatalysts shows an increase of the first-order rate constant in the order chitosan < gelatin < bovine serum albumin (BSA) < collagen. The results of this study indicate that simple edible gelatin can promote C-C bond forming reactions under physiological conditions, which may have important implications from a metabolic perspective.

10abiocatalysis10acarbon-carbon bond formation10agelatin10aHenry reaction10aprotein1 aKuehbeck, Dennis1 aDhar, Basab, Bijayi1 aSchoen, Eva-Maria1 aCativiela, Carlos1 aGotor-Fernandez, Vicente1 aDiaz, David, Diaz uhttps://library.ncl.res.in/content/c-c-bond-formation-catalyzed-natural-gelatin-and-collagen-proteins-001926nas a2200265 4500008004100000022001400041245012800055210006900183260007700252300001600329490000700345520092500352653002001277653003201297653002101329653002401350653001901374100001901393700003101412700002201443700002201465700002401487700002001511856012901531 2014 eng d a0947-653900aCovalent organic framework-cadmium sulfide hybrid as a prototype photocatalyst for visible-light-driven hydrogen production0 aCovalent organic frameworkcadmium sulfide hybrid as a prototype  aBOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcNOV a15961-159650 v203 a

CdS nanoparticles were deposited on a highly stable, two-dimensional (2D) covalent organic framework (COF) matrix and the hybrid was tested for photocatalytic hydrogen production. The efficiency of CdS-COF hybrid was investigated by varying the COF content. On the introduction of just 1 wt% of COF, a dramatic tenfold increase in the overall photocatalytic activity of the hybrid was observed. Among the various hybrids synthesized, that with 10 wt% COF, named CdS-COF (90: 10), was found to exhibit a steep H2 production amounting to 3678 mmolh(-1) g(-1), which is significantly higher than that of bulk CdS particles (124 mmolh(-1)g(-1)). The presence of a p-conjugated backbone, high surface area, and occurrence of abundant 2D hetero-interface highlight the usage of COF as an effective support for stabilizing the generated photoelectrons, thereby resulting in an efficient and high photocatalytic activity.

10acharge transfer10acovalent organic frameworks10ahybrid materials10ahydrogen production10aPhotocatalysis1 aThote, Jayshri1 aAiyappa, Harshitha, Barike1 aDeshpande, Aparna1 aDiaz, David, Diaz1 aKurungot, Sreekumar1 aBanerjee, Rahul uhttps://library.ncl.res.in/content/covalent-organic-framework-cadmium-sulfide-hybrid-prototype-photocatalyst-visible-light-001627nas a2200169 4500008004100000245008800041210006900129260000800198300001200206490000700218520102900225100001901254700002001273700002201293700002201315856012001337 2017 eng d00aCatalytic macroporous biohydrogels made of ferritin-encapsulated gold nanoparticles0 aCatalytic macroporous biohydrogels made of ferritinencapsulated  cFEB a225-2320 v823 aReported is a modular approach for the incorporation and stabilization of gold nanoparticles inside a three-dimensional macroporous hydrogel made of ferritin. The strategy, which involves the dynamic templating of surfactant H-1 domains, demineralization, and remineralization helps to overcome aggregation and degradation issues usually associated with bare-metal-based nanocatalysts. The catalytic activity of the so-synthesized bionanocomposite hydrogel was demonstrated in both nitroaldol (Henry) and nitroreduction model reactions in aqueous solution at room temperature. An interesting synergistic effect between basic residues of the protein and the gold nanoparticles was found in the nitroaldol reaction when carried out in water in the presence of a phase-transfer catalyst. Furthermore, the reduction of 4-nitrophenol and 4-nitroaniline catalyzed by the nanocomposite scaffold in the presence of NaBH4 proceeded significantly faster than that using other known Au- and Ag-based catalysts under similar conditions.1 aKumari, Sushma1 aHaring, Marleen1 aGupta, Sayam, Sen1 aDiaz, David, Diaz uhttps://library.ncl.res.in/content/catalytic-macroporous-biohydrogels-made-ferritin-encapsulated-gold-nanoparticles