01787nas a2200241   4500008004100000022001400041245013600055210006900191260007700260300001600337490000700353520085500360653002401215653001901239653002901258653002101287653002801308100001801336700002101354700002001375700001901395856013101414       2014                        eng d  a0947-653900aEvolution of an adenine-copper cluster to a highly porous cuboidal framework: solution-phase ripening and gas-adsorption properties0 aEvolution of an adeninecopper cluster to a highly porous cuboida  aBOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcSEP  a12262-122680 v203 a<p>The synthesis and directed evolution of a tetranu-clear copper cluster, supported by 8-mercapto-N9-propyladenine ligand, to a highly porous three-dimensional cubic framework in the solid state is reported. The structure of this porous framework was unambiguously characterized by Xray crystallography. The framework contains about 62% solvent-accessible void; the presence of a free exocyclic amino group in the porous framework facilitates reversible adsorption of gas and solvent molecules. Oriented growth of framework in solution was also tracked by force and scanning electron microscopy studies, leading to identification of an intriguing ripening process, over a period of 30 days, which also revealed formation of cuboidal aggregates in solution. The elemental composition of these cuboidal aggregates was ascertained by EDAX analysis.</p>10acuboidal frameworks10agas adsorption10ametal-organic frameworks10aOstwald ripening10asolution-phase ripening1 aVenkatesh, V.1 aPachfule, Pradip1 aBanerjee, Rahul1 aVerma, Sandeep  uhttps://library.ncl.res.in/content/evolution-adenine-copper-cluster-highly-porous-cuboidal-framework-solution-phase-ripening-001915nas a2200241   4500008004100000022001400041245007500055210006900130260011000199300001400309490000600323520105000329100001701379700002301396700002401419700001801443700002001461700002601481700001801507700001901525700002001544856010901564       2015                        eng d  a2041-652000aChemical sensing in two dimensional porous covalent organic nanosheets0 aChemical sensing in two dimensional porous covalent organic nano  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcAPR  a3931-39390 v63 a<p>Two new imide-based crystalline, porous, and chemically stable covalent organic frameworks (COFs) (TpBDH and TfpBDH) have been successfully synthesized employing solvothermal crystallization route. Furthermore, thin layered covalent organic nanosheets (CONs) were derived from these bulk COFs by the simple liquid phase exfoliation method. These 2D CONs showcase increased luminescence intensity compared to their bulk counterparts (COFs). Notably, TfpBDH-CONs showcase good selectivity and prominent, direct visual detection towards different nitroaromatic analytes over TpBDH-CONs. Quite interestingly, TfpBDH-CONs exhibit a superior ``turn-on'' detection capability for 2,4,6-trinitrophenol (TNP) in the solid state, but conversely, they also show a ``turn-off'' detection in the dispersion state. These findings describe a new approach towards developing an efficient, promising fluorescence chemosensor material for both visual and spectroscopic detection of nitroaromatic compounds with very low [10(-5) (M)] analyte concentrations.</p>1 aDas, Gobinda1 aBiswal, Bishnu, P.1 aKandambeth, Sharath1 aVenkatesh, V.1 aKaur, Gagandeep1 aAddicoat, Matthew, A.1 aHeine, Thomas1 aVerma, Sandeep1 aBanerjee, Rahul  uhttps://library.ncl.res.in/content/chemical-sensing-two-dimensional-porous-covalent-organic-nanosheets-001796nas a2200217   4500008004100000022001400041245008100055210006900136260009000205300000900295490000600304520100700310100002401317700001801341700002501359700001901384700001801403700001901421700002001440856011801460       2015                        eng d  a2041-172300aSelf-templated chemically stable hollow spherical covalent organic framework0 aSelftemplated chemically stable hollow spherical covalent organi  aMACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLANDbNATURE PUBLISHING GROUPcAPR  a67860 v63 a<p>Covalent organic frameworks are a family of crystalline porous materials with promising applications. Although active research on the design and synthesis of covalent organic frameworks has been ongoing for almost a decade, the mechanisms of formation of covalent organic frameworks crystallites remain poorly understood. Here we report the synthesis of a hollow spherical covalent organic framework with mesoporous walls in a single-step template-free method. A detailed time-dependent study of hollow sphere formation reveals that an inside-out Ostwald ripening process is responsible for the hollow sphere formation. The synthesized covalent organic framework hollow spheres are highly porous (surface area similar to 1,500m(2) g(-1)), crystalline and chemically stable, due to the presence of strong intramolecular hydrogen bonding. These mesoporous hollow sphere covalent organic frameworks are used for a trypsin immobilization study, which shows an uptake of 15.5 mu mol g(-1) of trypsin.</p>1 aKandambeth, Sharath1 aVenkatesh, V.1 aShinde, Digambar, B.1 aKumari, Sushma1 aHalder, Arjun1 aVerma, Sandeep1 aBanerjee, Rahul  uhttps://library.ncl.res.in/content/self-templated-chemically-stable-hollow-spherical-covalent-organic-framework-1