01181nas a2200193 4500008004100000022001400041245012300055210006900178260007100247300001200318490000700330520043100337100001900768700001400787700001700801700002000818700001800838856013100856 2014 eng d a1528-748300aLigand-free one-step synthesis of {001} faceted semiconducting BiOCl single crystals and their photocatalytic activity0 aLigandfree onestep synthesis of 001 faceted semiconducting BiOCl a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcJAN a236-2390 v143 a

Herein, we report one-step ligand-free hydrothermal synthesis of predominantly {001}-faceted micron-sized single crystals of bismuth oxychloride (BiOCl). The structural chlorine is obtained by in situ generation of chloride ions. From Raman spectra, we could resolve the E-g transition. Photocatalytic activity of as-synthesized crystals showed 78% degradation of RhB dye under a xenon source after 120 min of exposure.

1 aBiswas, Anupam1 aDas, Raja1 aDey, Chandan1 aBanerjee, Rahul1 aPoddar, Panka uhttps://library.ncl.res.in/content/ligand-free-one-step-synthesis-001-faceted-semiconducting-biocl-single-crystals-and-their-002212nas a2200229 4500008004100000245008800041210006900129260000800198300001400206490000600220520141800226100001901644700002701663700003101690700002301721700002401744700002501768700002801793700002401821700002001845856011701865 2017 eng d00aFacile synthesis and self-cleaning application of bimetallic (CuSn, CuNi) dendrites0 aFacile synthesis and selfcleaning application of bimetallic CuSn cJUL a5552-55630 v23 a

Bimetallic dendrites (Au, Ag, Pt, Pd) have received intense research interest due to their applications in catalysis and sensing. However, reports on rational synthesis of non-noble bimetallic dendrites that finds self-cleaning applications are scanty. Here, we demonstrate one step co-reduction based galvanic replacement reaction (GRR) for synthesis of alloyed bimetallic dendrites (CuSn, CuNi) with controlled surface roughness and chemical composition. Probing their growth process reveals that i) for CuSn dendrites, co-reduction of Cu2+ and Sn2+ is observed throughout GRR; ii) for CuNi dendrites, Cu nanoparticle, that deposits initially, augments the reduction of Ni2+ which leads to CuNi alloy phase formation during later stages of GRR. These dendrites, naturally having dual degree of surface roughness (micro/nano), have been exploited here for fabricating superhydrophobic surfaces (SHS) with excellent self-cleaning abilities. They show enabling properties such as high contact angle, minimal contact angle hysteresis, and excellent Cassie state stability with no impalement. They maintain superhydrophobicity when exposed to different environmental conditions (low temperature, high temperature, exposure to corroding solutions and UV radiation). The present facile methodology for fabrication of bimetallic dendrites is beneficial for low-cost production of functional nano/micro-materials.

1 aBiswas, Anupam1 aKulkarni, Mayuresh, A.1 aBakthavatsalam, Rangarajan1 aMondal, Sourik, K.1 aDwivedi, Pravin, K.1 aShelke, Manjusha, V.1 aDevi, Radhamonyamma, N.1 aBanpurkar, Arun, G.1 aKundu, Janardan uhttps://library.ncl.res.in/content/facile-synthesis-and-self-cleaning-application-bimetallic-cusn-cuni-dendrites02812nas a2200217 4500008004100000245016800041210006900209260000800278300001200286490000600298520200000304100001902304700002302323700001402346700002102360700001602381700002102397700002502418700001902443856013202462 2017 eng d00aOxidant mediated one-step complete conversion of multi-walled carbon nanotubes to graphene quantum dots and their bioactivity against mammalian and bacterial cells0 aOxidant mediated onestep complete conversion of multiwalled carb cJAN a785-7960 v53 aIt is essential for any antibacterial agent (for clinical applications) that it should have high and selective toxicity towards bacterial cells only, and should not affect the human cells at the concentration used. Graphene quantum dots (GQDs) have emerged as a potential candidate for biomedical applications. However, a simple, low cost, safe, easy to execute, one-step synthesis of uniform and monodispersed GQDs with selective toxicity towards bacterial cells rather than mammalian cells is difficult to achieve. Herein, we have reported a one-step, low-cost, aqueous-phase, simple approach for the complete conversion of multi-walled carbon nanotubes into water-dispersible GQDs with an average size of similar to 3 nm using sodium bismuthate (NaBiO3) as a strong oxidant. The cyclic voltammetry and X-ray photoelectron spectroscopy results indicated that the as-synthesized GQDs suspension possess almost negligible amounts of metallic impurities. The cytotoxicity studies of GQDs against mammalian NIH 3T3 (mouse embryo fibroblast cells) and HEK 293T (human embryonic kidney cells) cells showed that the as-synthesized GQDs were non-cytotoxic up to the concentration of similar to 200 mu g mL(-1). The antimicrobial study shows that the synthesized GQDs have high and selective toxicity towards bacterial cells with a minimum inhibitory concentration of similar to 256 mu g mL(-1) for E. coli and B. subtilis and similar to 512 mu g mL(-1) for P. aeruginosa and S. aureus. The scanning electron microscopy and atomic force microscopy images show extensive cell damage via the perturbation of bacterial cell walls, which was consistent with the enhancement of reactive oxygen species production by almost two times in the bacterial cells upon incubation with similar to 256 mu g mL(-1) GQDs. Our study suggested that the as-synthesized GQDs can be used as a potential candidate for clinical applications as they possess high toxicity to bacterial cells and low toxicity to mammalian cells.1 aBiswas, Anupam1 aKhandelwal, Puneet1 aDas, Raja1 aSalunke, Gayatri1 aAlam, Aftab1 aGhorai, Suvankar1 aChattopadhyay, Samit1 aPoddar, Pankaj uhttps://library.ncl.res.in/content/oxidant-mediated-one-step-complete-conversion-multi-walled-carbon-nanotubes-graphene-quantum00796nas a2200217 4500008004100000022001400041245012200055210006900177260000900246300001400255490000700269100001900276700003100295700002200326700001900348700001800367700001700385700002400402700002000426856013200446 2019 eng d a0897-475600aEfficient broad-band emission from contorted purely corner-shared one dimensional (1D) organic lead halide perovskite0 aEfficient broadband emission from contorted purely cornershared  cAPR  a2253-22570 v311 aBiswas, Anupam1 aBakthavatsalam, Rangarajan1 aShaikh, Samir, R.1 aShinde, Aparna1 aLohar, Amruta1 aJena, Satyam1 aGonnade, Rajesh, G.1 aKundu, Janardan uhttps://library.ncl.res.in/content/efficient-broad-band-emission-contorted-purely-corner-shared-one-dimensional-1d-organic-lead02322nas a2200205 4500008004100000022001400041245014500055210006900200260000800269300001400277490000800291520154500299100003101844700001901875700001901894700002901913700002201942700002001964856013201984 2019 eng d a1932-744700aTemperature-dependent photoluminescence and energy-transfer dynamics in Mn2+-doped (C4H9NH3)(2)PbBr4 two-dimensional (2D) layered perovskite0 aTemperaturedependent photoluminescence and energytransfer dynami cFEB a4739-47480 v1233 a

Reported here are the low-temperature photoluminescence (PL), energy-transfer mechanism, and exciton dynamics of Mn2+-doped two-dimensional (2D) perovskites that show interesting differences from their three-dimensionally doped counterpart. Dopant emission in 2D system shows increased PL intensity and shortened lifetime with increase of temperature and strong dopant emission even at low temperatures. Transient absorption (TA) spectroscopy reveals the dominant role of ``hot'' excitons in dictating the fast energy-transfer timescale. The operative dynamics of the generated hot excitons include filling up of existing trap states (shallow and deep) and energy-transfer channel from hot excitons to dopant states. Global analysis and target modeling of TA data provide an estimate of excitons (hot and band edge) to a dopant energy-transfer timescale of similar to 330 ps, which is much faster than the band edge exciton lifetime (similar to 2 ns). Such fast energy-transfer timescale arises due to enhanced carrier exchange interaction resulting from higher exciton confinement, increased covalency, and involvement of hot excitons in the 2D perovskites. In stark contrast to three-dimensional systems, the high energy-transfer rate in 2D system results in high dopant emission intensity even at low temperatures. Increased intrinsic vibronic coupling at higher temperatures further supports efficient Mn2+ sensitization that ultimately dictates the observed temperature dependence of the dopant emission (intensity, lifetime).

1 aBakthavatsalam, Rangarajan1 aBiswas, Anupam1 aChakali, Madhu1 aBangal, Prakriti, Ranjan1 aKore, Bhushan, P.1 aKundu, Janardan uhttps://library.ncl.res.in/content/temperature-dependent-photoluminescence-and-energy-transfer-dynamics-mn2-doped-c4h9nh32pbbr402039nas a2200229 4500008004100000022001400041245013300055210006900188260000900257300001400266490000600280520121500286100001901501700003101520700001701551700002001568700002401588700002701612700002401639700002001663856012601683 2021 eng d a2050-752600aLead-free zero dimensional tellurium(iv) chloride-organic hybrid with strong room temperature emission as a luminescent material0 aLeadfree zero dimensional telluriumiv chlorideorganic hybrid wit cMAR  a4351-43580 v93 a

Despite the current progress in `Pb-free' low dimensional main group metal halide based luminescent materials, it is challenging to synthesize Te(iv) halide hybrids with strong ambient emission with excitation features in the visible range as efficient and stable phosphors for potential lighting applications. Reported here is a (benzyltriethylammonium)(2)TeCl6 zero dimensional hybrid material with excitation features in the visible range and strong room temperature, broadband, intrinsic luminescence (PLQY similar to 15%) arising due to self-trapped excitons (STEs). Furthermore, a proof-of-concept LED architecture demonstrates successful optical down-conversion with a visible light excitation source. Here, exclusive adoption of a `regular' octahedral Te(iv)-halide unit structure with minimal static distortion provides a unique opportunity to unmask the role played by 5s(2) lone pair electrons in shaping the emissive properties. This effort may open up new avenues towards unravelling the role of lone pair stereoactivity in controlling the PLQY in low dimensional hybrids that has proven to be challenging for the reported (Sb, Sn) based low dimensional 5s(2) metal halide hybrid materials.

1 aBiswas, Anupam1 aBakthavatsalam, Rangarajan1 aBahadur, Vir1 aBiswas, Chinmoy1 aMali, Bhupendra, P.1 aRaavi, Sai, Santosh Ku1 aGonnade, Rajesh, G.1 aKundu, Janardan uhttps://library.ncl.res.in/content/lead-free-zero-dimensional-telluriumiv-chloride-organic-hybrid-strong-room-temperature02548nas a2200229 4500008004100000022001400041245016300055210006900218260000900287300001200296490000600308520169200314100001902006700003102025700002402056700001702080700002002097700002702117700002402144700002002168856013002188 2021 eng d a2050-752600aMetal halide structure and the extent of distortion control the photo-physical properties of luminescent zero dimensional organic-antimony(iii) halide hybrids0 aMetal halide structure and the extent of distortion control the  cJAN  a348-3580 v93 a

Antimony(iii) halide based zero dimensional hybrids have gained attention as broadband emitters. Until now, quadrangular pyramidal SbX5 based and octahedral SbX6 based 0D hybrids have been reported utilizing different organic ligands demonstrating some structural tunability affecting their emissive properties. Utilizing a common organic ligand, here we demonstrate the structural tunability (quadrangular pyramidal, octahedral, or a combination thereof) of the metal halide unit in Sb(iii)Cl 0D hybrids with contrasting photo-physical properties (broadband, Stokes shift, strong/weak colored emission). The structure-property-mechanism correlation of the synthesized compounds [1 (C12H52Cl18N8O4Sb3; tris Sb green); 2 (C12H50Cl14N8O3Sb2; tris Sb red); 3 (C24H88Cl25N16O4Sb3; tris Sb yellow)] identifies crucial factors that control their emissive properties. The X-ray analysis reveals the structure (1-octahedral; 2-quadrangular pyramidal; 3-combination thereof) and the order of the extent of structural distortion as 1-3 MUCH LESS-THAN 2. The metal halide coordination environment asymmetry and its structure are observed to dictate PL emission energy (1-green; 2-red; 3-yellow) as supported by a qualitative Molecular Orbital scheme. The extent of structural distortion guides the observed Stokes shifts (1-165 nm; 2-290 nm; 3-200 nm; 1-3 < 2). Interestingly, the extent of distortion is found to be well correlated with the observed PLQY (1-45%; 2-6%; 3-43%; 1-3 >> 2). This report clearly demonstrates the structural tunability and the effect of the metal halide unit structure/distortion in shaping the emissive properties of 0D organic Sb(iii) halide hybrids.

1 aBiswas, Anupam1 aBakthavatsalam, Rangarajan1 aMali, Bhupendra, P.1 aBahadur, Vir1 aBiswas, Chinmoy1 aRaavi, Sai, Santosh Ku1 aGonnade, Rajesh, G.1 aKundu, Janardan uhttps://library.ncl.res.in/content/metal-halide-structure-and-extent-distortion-control-photo-physical-properties-luminescent02784nas a2200289 4500008004100000022001400041245016800055210006900223260000900292300001200301490000700313520176900320100001902089700003102108700001802139700001602157700002402173700002002197700002102217700002002238700002702258700002402285700002402309700001902333700002002352856012202372 2021 eng d a2050-752600aSynergistic electronic coupling/cross-talk between the isolated metal halide units of zero dimensional heterometallic (Sb, Mn) halide hybrid with enhanced emission0 aSynergistic electronic couplingcrosstalk between the isolated me cDEC  a360-3700 v103 aHeterometallic 0D metal halide hybrids, consisting of more than one kind of metal halide units, are anticipated to manifest synergistic effects on the photo-physical properties of the constituent metal halide units. Such architectures hold great promise for design and development of function-targeted materials. However, heterometallic 0D hybrids, featuring isolated metal halide units, typically do not show any synergistic effects due to large inter-unit spatial separations that inhibit interactions/coupling between the constituent metal halide units. It remains challenging to design synthetic strategies that would support structural modifications to allow synergistic electronic coupling between the metal halide units in heterometallic 0D hybrids. Here, we report synthesis and characterization of heterometallic (Sb, Mn) 0D hybrid, namely Tris SbMnCl, with isolated MnCl5 units, (Sb/Mn)Cl-6 units, dispersed in the organic ligand matrix and layer of dynamic and networked water molecules. Steady state and time resolved emission spectra (TRES) analysis suggests strong synergistic interaction between the isolated metal halide units. Efficient energy transfer from the strongly absorbing Sb centres to emissive Mn centres results in the observed enhanced emission. Proton conductivity measurements together with first-principles calculations suggest the unique role of the networked water molecules in mediating the electronic coupling/energy transfer between the separated metal halide units in Tris SbMnCl hybrid. This report highlights the role of structure/composition of the synthesized heterometallic 0D hybrid in attaining electronic dimensionality higher than 0D through synergistic electronic interaction between the isolated metal halide units.1 aBiswas, Anupam1 aBakthavatsalam, Rangarajan1 aDas, Deep, K.1 aSam, Jisvin1 aMali, Bhupendra, P.1 aBiswas, Chinmoy1 aMaana, Narugopal1 aThomson, Stuart1 aRaavi, Sai, Santosh Ku1 aKurungot, Sreekumar1 aGonnade, Rajesh, G.1 aDutta, Sudipta1 aKundu, Janardan uhttps://library.ncl.res.in/content/synergistic-electronic-couplingcross-talk-between-isolated-metal-halide-units-zero02590nas a2200205 4500008004100000022001400041245011100055210006900166260000900235300001400244490000700258520185700265100002402122700002502146700001902171700001702190700002402207700002402231856012902255 2022 eng d a1528-748300aPolymorphs of green fluorescence protein chromophore analogue: fluorescence switching with thermal stimuli0 aPolymorphs of green fluorescence protein chromophore analogue fl cMAR  a1892-19050 v223 a

Polymorphs of fluorescent organic materials offer significant implications in optoelectronics and advanced materials as they modulate photoluminescence properties. A slight alteration in the conformation/packing of molecules in the crystals shows variation in photoluminescence. This necessitates the polymorph screening of these materials to develop novel crystalline forms with distinct fluorescence emissions for broader application. In continuation of our work on the polymorph screening of Green Fluorescence Protein Chromophore (GFPc), we have synthesized a new imidazoline derivative, ethyl (Z)-2-(2-methyl-5-oxo-4-(3,4,5-trimethoxybenzylidene)-4,5-dihydro-1H-imi dazol-1- yl)acetate (1). Polymorph screening of 1 under different crystallization conditions revealed three polymorphs, Form I (needle), Form II (block), and Form III (polycrystalline material). Forms I and II are the outcome of solution crystallization, whereas Form III was produced from the melt crystallization of Forms I and II. DSC, HSM, and powder and single-crystal XRD studies indicate the conversion of Form I and Form III crystals to Form II crystals on thermal stimuli. The photoluminescence studies revealed cyan, yellow, and yellowish-green fluorescence emission for Forms I, II, and III crystals, respectively. The difference in photoluminescence could be due to the variance in aggregation modes like H-aggregation in Form I and J-aggregation in Form II crystals. Form I, Form II, and Form III crystals also showed irreversible thermal fluorescent switching from cyan-yellow-green due to polymorphic phase transitions. The study correlates the direct observation of the modulation of the excited-state transition under thermal stimuli in the crystalline phase. It will help augment the pace in the research of thermally responsive fluorescent materials.

1 aMali, Bhupendra, P.1 aDash, Soumya, Ranjan1 aBiswas, Anupam1 aVanka, Kumar1 aManoj, Kochunnoonny1 aGonnade, Rajesh, G. uhttps://library.ncl.res.in/content/polymorphs-green-fluorescence-protein-chromophore-analogue-fluorescence-switching-thermal02706nas a2200217 4500008004100000022001400041245019500055210006900250260000900319300001400328490000700342520186000349100002402209700002502233700002102258700001902279700002402298700001702322700002402339856012502363 2023 eng d a1528-748300aCocrystal approach to modulate the photoluminescent properties of a GFP chromophore analogue: role of halogen/hydrogen bonding in achieving a wide range of solid-state fluorescence emissions0 aCocrystal approach to modulate the photoluminescent properties o cJUN  a5052-50650 v233 a

Fine-tuning the photophysical properties of fluorescentorganicsolids is essential to attain multicolor displays and meet the demandfor futuristic light-emitting materials. Here, we report the tunableluminescence of a green fluorescent protein (GFP) chromophore analogue,3,4,5-TIA (A), based on the formation of two-component molecular cocrystalswith six different coformers. Coformers selected to synthesize thebinary cocrystals include 1,4-diiodotetrafluorobenzene (B), perfluoronaphthalene(C), 1,4-dibromotetrafluorobenzene (D), 2,3,5,6-tetrafluoroterephthalicacid (E), benzene-1,2,4,5-tetracarbonitrile (F), and benzene-1,2,4,5-tetracarboxylicacid (G). Interestingly, the cocrystals A center dot C and A center dot Fshowed molecular crystal polymorphism with a slight variation in fluorescence,revealing an aggregation-induced emission (AIE). A crystal structureanalysis showed the interplay of hydrogen bonding, halogen bonding,and aromatic pi-stacking interactions in associating neutralsolid components in the cocrystal. All of the novel cocrystals displayeda wide range of photoluminescence ranging from blue to dark orange.The time-dependent density functional theory (TD-DFT) calculationsindicate the changes in the energy level structures (HOMO to LUMO)in cocrystals that resulted in variations in fluorescence emission.The study aims to further understand the structure-propertyrelationship between molecular arrangement and photoluminescence. Cocrystals of a GFPc analogue with differentcoformers displayeda wide range of fluorescence emissions ranging from blue to dark orangewith varying quantum yields. With similar geometries of pi-stackinginteractions, hydrogen and halogen bonding have played a vital rolein fine-tuning the photoluminescence; halogen bonding leads to a blueshift, and hydrogen bonding results in a red shift.

1 aMali, Bhupendra, P.1 aDash, Soumya, Ranjan1 aAnnadhasan, Mari1 aBiswas, Anupam1 aManoj, Kochunnoonny1 aVanka, Kumar1 aGonnade, Rajesh, G. uhttps://library.ncl.res.in/content/cocrystal-approach-modulate-photoluminescent-properties-gfp-chromophore-analogue-role01496nas a2200217 4500008004100000022001400041245012100055210006900176260000800245300001400253490000700267520072100274100002400995700002201019700002101041700001901062700001701081700002401098700002401122856013201146 2025 eng d a1528-748300aSynthesis and concomitant polymorphs of green fluorescence protein chromophore-anthracene-based fluorescent analogue0 aSynthesis and concomitant polymorphs of green fluorescence prote cFEB a1011-10220 v253 a

Controlled variations in fluorescence properties hold significant promise for applications in optical sensors, bioimaging, and advanced display devices. However, constructing multicolor fluorescent systems remains a challenge. In this study, we demonstrate the development of multicolor fluorescence by generating polymorphs of a novel green fluorescent protein chromophore analogue, which exhibits distinct photoluminescence emissions in the solid state. The observed emission variations are attributed to differences in molecular conformation due to variations in pi-stacking interactions between the polymorphs. This offers a novel approach to designing materials with tunable fluorescence properties.

1 aMali, Bhupendra, P.1 aDabke, Niteen, B.1 aDash, Soumya, R.1 aBiswas, Anupam1 aVanka, Kumar1 aManoj, Kochunnoonny1 aGonnade, Rajesh, G. uhttps://library.ncl.res.in/content/synthesis-and-concomitant-polymorphs-green-fluorescence-protein-chromophore-anthracene-based