01915nas 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-0