01230nas a2200217 4500008004100000022001400041245008600055210006900141260000800210520048700218653001700705653003000722653002200752100002300774700001900797700002000816700002200836700001900858700002500877856011000902 2019 eng d a2193-580700aRegioselective one-pot synthesis of 3-fluoro-imidazo[1,2-a]pyridines from styrene0 aRegioselective onepot synthesis of 3fluoroimidazo12apyridines fr cOCT3 a

A one-pot synthesis of C-3 fluorinated imidazopyridines (F-IMPY) is reported under the additive-free conditions from commercially available styrene and 1-fluoropyridinium tetrafluoroborate as a fluorine source. The substrate styrene undergoes keto-bromination/condensation/fluorination transformation in three sequential steps to furnish F-IMPY. This one-pot synthesis method exhibits broad substrate scope and good functional group tolerance with a good yield (up to 82%).

10afluorination10aimidazopyridines (F-IMPY)10aOne-pot synthesis1 aSaid, Madhukar, S.1 aMishra, Ankita1 aPandole, Satish1 aNayak, Rashmi, A.1 aKumar, Pradeep1 aGajbhiye, Jayant, M. uhttps://library.ncl.res.in/content/regioselective-one-pot-synthesis-3-fluoro-imidazo12-apyridines-styrene02258nas a2200253 4500008004100000022001400041245012900055210006900184260000800253300001200261490000600273520138200279653001401661653003801675653002001713653002201733653001501755100001801770700002001788700002101808700002201829700002301851856013001874 2020 eng d a2367-093200aConjunctive photoluminescence enhancement through plasmonic and photonic band-gap pathways in a chiral self-assembled system0 aConjunctive photoluminescence enhancement through plasmonic and  cAUG a582-5910 v43 a

We describe two parallel pathways for enhancing the intrinsic photoluminescence of an organic emitter dispersed in a liquid crystal (LC) medium. The pathways have independent origins: (i) Metal enhanced fluorescence (MEF) incorporating gold nanoparticles having an organic shell of pro-mesogenic cholesterol esters; and (ii) Matching the photonic band gap (PBG) due to the helical structure in a self-assembled chiral system with the excitation wavelength. This unprecedented combination of both pathways achieves a level of photoluminescence exceeding the sum of the contribution from the individual methods. This conjunctive protocol results in an overall enhancement by a factor of 37 between the emitter dispersed in a non-chiral LC and that appealing to both MEF and PBG pathways. Circular polarized luminescence measurements also show that this protocol helps in effective discrimination of chiral light achieving a large dissymmetry factor whose magnitude (+0.33) is comparable to the highest recorded to date. Electric field switching between two states is also shown to result in appreciable fluorescence modulation. Being generic in nature the protocol employed can be adapted to a variety of situations with the large magnitude as well the modulation level suitable for applications such as biosensors, various analyte detection, and other photonic devices.

10achirality10acircularly polarized luminescence10aliquid crystals10aphotonic band-gap10aplasmonics1 aBaral, Marlin1 aPrasad, Krishna1 aBhat, Sachin, A.1 aNayak, Rashmi, A.1 aYelamaggad, C., V. uhttps://library.ncl.res.in/content/conjunctive-photoluminescence-enhancement-through-plasmonic-and-photonic-band-gap-pathways01590nas a2200181 4500008004100000022001400041245007400055210006900129260000900198300001400207490000700221520098100228100001801209700002601227700002201253700003001275856010301305 2021 eng d a1477-052000aAggregation-induced phosphorescence of an anthraquinone based emitter0 aAggregationinduced phosphorescence of an anthraquinone based emi cFEB  a1004-10080 v193 a

Room temperature phosphorescence (RTP) of metal-free organic molecules is a hot topic of current research interest. RTP can be enhanced through aggregation, crystallization, and the support of polymers and host-guest assemblies. The characteristics of highly phosphorescent aggregates formed from conventional chromophores make them ideal candidates for many potential applications. In this direction, we focused on the aggregation-induced phosphorescence of an anthraquinone derivative AqC6 in solution and in crystal state. The weakly emissive dilute solution exhibits a tunable emission with enhanced intensity and room temperature phosphorescence by increasing the concentration and solvent-antisolvent combination. The enhanced phosphorescence of crystals has been recreated in the solution by making use of aggregation. Interestingly, the support of PMMA enabled AqC6 to achieve enhanced processability, phosphorescence lifetime (174 ms) and quantum yield (5%).

1 aGoudappagouda1 aNidhankar, Aakash, D.1 aNayak, Rashmi, A.1 aBabu, Sukumaran, Santhosh uhttps://library.ncl.res.in/content/aggregation-induced-phosphorescence-anthraquinone-based-emitter