01132nas a2200169 4500008004100000245007700041210007100118260000800189300001400197490000700211520051400218100002600732700003000758700003300788700002400821856011700845 2016 eng d00aFluoride-mediated dephosphonylation of α-diazo-β-carbonyl phosphonates0 aFluoridemediated dephosphonylation of αdiazoβcarbonyl phosphonat cDEC a372 - 3750 v193 aThe possibility of fluoride-mediated selective dephosphonylation of α-diazo-β-carbonyl phosphonates such as the Ohira-Bestmann reagent has been proposed and executed. The resulting α-diazocarbonyl intermediates undergo a (3 + 2)-cycloaddition at room temperature with conjugated olefins and benzynes. Interestingly, under the current conditions, the resulting cycloaddition products underwent either N-acylation (with excess α-diazo-β-carbonyl phosphonates) or Michael addition (with conjugated olefins).1 aPhatake, Ravindra, S.1 aMullapudi, Venkanna, Babu1 aWakchaure, Vivek, Chandrakan1 aRamana, Chepuri, V. uhttps://library.ncl.res.in/content/fluoride-mediated-dephosphonylation-%CE%B1-diazo-%CE%B2-carbonyl-phosphonates01705nas a2200181 4500008004100000245012300041210006900164260000800233300001400241490000700255520098100262100001801243700003301261700003801294700003101332700003001363856013001393 2017 eng d00aCascade energy transfer and tunable emission from nanosheet hybrids: locating acceptor molecules through chiral doping0 aCascade energy transfer and tunable emission from nanosheet hybr cJUL a7072-70750 v533 aLight harvesting donor-acceptor assemblies are indispensable to efficiently tap photons. In an attempt to improve the light harvesting efficiency of an acceptor doped assembly, we design and synthesize a donor-acceptor-donor triad which exhibits an exceptional intramolecular energy transfer with excellent efficiency. Moreover, a facile cascade energy transfer (energy funnelling) is observed in the presence of a series of second acceptors (63-91% efficiency) with tunable emission colours. Self-assembled nanosheets formed by the triad in the presence of acceptors exhibit cascade energy transfer assisted tunable emission. In addition, use of chiral acceptors induces chirality to the triad and results in the formation of chiral nanosheets alongwith cascade energy transfer. Here chiral induction, nanosheet formation and cascade energy transfer in the presence of chiral acceptors are used as tools to probe the intercalation of acceptor molecules in the donor scaffold.1 aGoudappagouda1 aWakchaure, Vivek, Chandrakan1 aRanjeesh, Kayaramkodath, Chandran1 aAbhai, Chalona, Antony Ral1 aBabu, Sukumaran, Santhosh uhttps://library.ncl.res.in/content/cascade-energy-transfer-and-tunable-emission-nanosheet-hybrids-locating-acceptor-molecules01605nas a2200205 4500008004100000022001400041245008900055210006900144260000800213520090400221653001001125653001801135653002401153653001101177653001201188100003301200700001501233700003001248856012101278 2019 eng d a2192-650600aBoron-conjugated pyrenes as fluorescence-based molecular probes and security markers0 aBoronconjugated pyrenes as fluorescencebased molecular probes an cJUL3 a

Boron-embedded aromatic hydrocarbons are a class of molecules known for their distinct electronic and/or optoelectronic properties and are thus suitable for many potential applications. Among those, boronic ester and acid containing molecules have been widely used for sensing and molecular recognition applications, respectively. We compared the sensing and molecular recognition properties of two boron-containing pyrene derivatives for fluoride and glucose sensing applications. The presence of four boronate ester groups enabled fluoride ion sensing at the mu M level. The boronic acid derivative is very selective towards glucose compared to other saccharides. Furthermore, we used the mechano-responsive fluorescence changes and self-assembly of these derivatives, respectively, for fluorescence-based inkless and ink (water)-based writing in invisible security labeling applications.

10aboron10acarbohydrates10amechanoluminescence10apyrene10asensors1 aWakchaure, Vivek, Chandrakan1 aDas, Tamal1 aBabu, Sukumaran, Santhosh uhttps://library.ncl.res.in/content/boron-conjugated-pyrenes-fluorescence-based-molecular-probes-and-security-markers00987nas a2200193 4500008004100000022001400041245014700055210006900202260000900271300001400280490000700294520021000301100001800511700003300529700003800562700003100600700003000631856013200661 2019 eng d a1359-734500aCascade energy transfer and tunable emission from nanosheet hybrids: locating acceptor molecules through chiral doping (vol 53, pg 7072, 2017)0 aCascade energy transfer and tunable emission from nanosheet hybr cJUN  a6462-64620 v553 a

Correction for `Cascade energy transfer and tunable emission from nanosheet hybrids: locating acceptor molecules through chiral doping' by Goudappagouda et al., Chem. Commun., 2017, 53, 7072-7075.

1 aGoudappagouda1 aWakchaure, Vivek, Chandrakan1 aRanjeesh, Kayaramkodath, Chandran1 aAbhai, Chalona, Antony Ral1 aBabu, Sukumaran, Santhosh uhttps://library.ncl.res.in/content/cascade-energy-transfer-and-tunable-emission-nanosheet-hybrids-locating-acceptor-molecules-002445nas a2200217 4500008004100000245009700041210006900138260000800207300001400215490000700229520166200236100003301898700000501931700001801936700003801954700002301992700002602015700003402041700003002075856012202105 2019 eng d00aCharge transfer liquid: a stable donor-acceptor interaction in the solvent-free liquid state0 aCharge transfer liquid a stable donoracceptor interaction in the cAUG a9371-93740 v553 a

Charge-transfer complexes have been an inspiration to develop many functional soft materials. However, most of those studies have focused on solution based assemblies wherein the explicit control of solvents and their polarity are crucial. In this context, we explore an efficient and stable charge transfer liquid using a solvent-free liquid dialkoxynaphthalene donor and a naphthalenediimide acceptor. It has been observed that irrespective of the donor-acceptor ratio, the charge-transfer liquid exhibited an unprecedented stability and retained characteristic features even at increased temperatures. The underlying intermolecular interactions leading to efficient CT have been examined by NMR techniques together with theoretical modelling studies. The concept of charge transfer liquid will be highly beneficial for the development of processable optoelectronically active materials.
 

1 aWakchaure, Vivek, Chandrakan1 a1 aGoudappagouda1 aRanjeesh, Kayaramkodath, Chandran1 aChakrabarty, Suman1 aRavindranathan, Sapna1 aRajamohanan, Pattuparambil, R1 aBabu, Sukumaran, Santhosh uhttps://library.ncl.res.in/content/charge-transfer-liquid-stable-donor-acceptor-interaction-solvent-free-liquid-state02056nas a2200241 4500008004100000022001400041245009200055210006900147260000800216300001600224490000800240520121300248100003801461700002601499700002901525700001801554700003301572700001801605700001501623700002401638700003001662856012201692 2019 eng d a0002-786300aImidazole-linked crystalline two-dimensional polymer with ultrahigh proton-conductivity0 aImidazolelinked crystalline twodimensional polymer with ultrahig cSEP a14950-149540 v1413 a

Proton-exchange membrane fuel cells are promising energy devices for a sustainable future due to green features, high power density, and mild operating conditions. A facile proton-conducting membrane plays a pivotal role to boost the efficiency of fuel cells, and hence focused research in this area is highly desirable. Major issues associated with the successful example of Nafion resulted in the search for alternate proton conducting materials. Even though proton carrier loaded crystalline porous organic frameworks have been used for protonconduction, the weak host-guest interactions limited their practical use. Herein, we developed a crystalline 2D-polymer composed of benzimidazole units as the integral part, prepared by the condensation of aryl acid and diamine in polyphosphoric acid medium. The imidazole linked-2D-polymer exhibits ultrahigh proton conductivity (3.2 X 10(-2) S cm(-1)) (at 95% relative humidity and 95 degrees C) in the pristine state, which is highest among the undoped porous organic frameworks so far reported. The present strategy of a crystalline proton-conducting 2D-polymer will lead to the development of new high performing crystalline solid proton conductor.

1 aRanjeesh, Kayaramkodath, Chandran1 aIlathvalappil, Rajith1 aVeer, Sairam, Dnyaneshwa1 aPeter, Joseph1 aWakchaure, Vivek, Chandrakan1 aGoudappagouda1 aRaj, Vipin1 aKurungot, Sreekumar1 aBabu, Sukumaran, Santhosh uhttps://library.ncl.res.in/content/imidazole-linked-crystalline-two-dimensional-polymer-ultrahigh-proton-conductivity01938nas a2200193 4500008004100000022001400041245012200055210006900177260000800246300001600254490000700270520121800277100003301495700001801528700001501546700002601561700003001587856012701617 2021 eng d a2040-336400aExcimer to exciplex transition through realization of donor-acceptor interactions in luminescent solvent-free liquids0 aExcimer to exciplex transition through realization of donoraccep cJUN a10780-107840 v133 aLuminescent solvent-free organic liquids are known for their enhanced quantum yield, color tunability, and availability of a matrix for other dopants to generate hybrid luminescent materials with improved features for newer applications. Herein, we report a donor-acceptor based luminescent ``exciplex liquid'' by utilizing the slightly different electron affinity of the acceptor molecules. A red-shifted broad exciplex emission exhibited by the donor-acceptor pair even at a lower concentration of the acceptor (0.001 equiv.) indicates high efficiency in the solvent-free state. A detailed NMR study revealed weak intermolecular interactions between the donor and acceptor in the solvent-free matrix that stabilizes the exciplex liquid. The failure of structurally similar solid counterparts to form an exciplex confirms the advantage of the available supportive liquid matrix. Besides, the luminescent exciplex liquid is found efficient in sensing application, which is unachievable by either the individual liquids or their solid counterparts. Here, a transition of a donor-acceptor pair from a solid to solvent-free liquid results in a new hybrid liquid that can be an alternative for solid sensor materials.1 aWakchaure, Vivek, Chandrakan1 aGoudappagouda1 aDas, Tamal1 aRavindranathan, Sapna1 aBabu, Sukumaran, Santhosh uhttps://library.ncl.res.in/content/excimer-exciplex-transition-through-realization-donor-acceptor-interactions-luminescent01605nas a2200229 4500008004100000022001400041245012100055210006900176260000900245300001400254490000700268520078700275100003301062700002101095700002601116700001801142700001801160700001801178700002601196700003001222856012301252 2022 eng d a1359-734500aDonor-acceptor based solvent-free organic liquid hybrids with exciplex emission and room temperature phosphorescence0 aDonoracceptor based solventfree organic liquid hybrids with exci cFEB  a1998-20010 v583 aSolvent-free organic liquids are well-known for their excellent luminescence features. Hence, the recent developments in this area have marked them as potential emitters with high quantum yield and enhanced processability. The support of an available liquid matrix enables doping to deliver hybrid liquids with intriguing luminescence features. In this direction, we report solvent-free liquid donor-acceptor pairs with exciplex emission and room temperature phosphorescence at very low acceptor loading. The underlying weak intermolecular interactions have been revealed by 2D NMR techniques and theoretical calculations. The formation of large-area thin films by exciplex and phosphorescent liquid hybrids will encourage the development of scalable lighting and display materials.1 aWakchaure, Vivek, Chandrakan1 aVeer, Sairam, D.1 aNidhankar, Aakash, D.1 aGoudappagouda1 aNayak, Rashmi1 aAsokan, Kiran1 aRavindranathan, Sapna1 aBabu, Sukumaran, Santhosh uhttps://library.ncl.res.in/content/donor-acceptor-based-solvent-free-organic-liquid-hybrids-exciplex-emission-and-room02177nas a2200253 4500008004100000022001400041245011800055210006900173260000800242490000700250520127800257653002001535653001901555653003301574653001401607653001601621100003301637700002901670700002601699700001801725700002201743700003001765856012801795 2023 eng d a1433-785100aPolymerizable solvent-free organic liquids: a new approach for large area flexible and foldable luminescent films0 aPolymerizable solventfree organic liquids a new approach for lar cAUG0 v623 a

The high demand for light-emitting and display devices made luminescent organic materials as attractive candidates. Solvent-free organic liquids are one of the promising emitters among them due to the salient features. However, the inherent limitations of forming sticky and noncurable surfaces must be addressed to become an alternate emitter for large-area device applications. Herein, we functionalized solvent-free organic liquids having monomeric emission in bulk with polymerizable groups to improve the processability. The polymerizable group on carbazole, naphthalene monoimide, and diketopyrrolopyrrole-based solvent-free liquid emitters enabled on-surface polymerization. These emitters alone and in combinations can be directly coated on a glass substrate without the help of solvents. Subsequent photo or thermal polymerization leads to stable, non-sticky, flexible, foldable, and free-standing large-area films with reasonably high quantum yield. Our demonstration of the tunable and white light-emitting films using polymerizable solvent-free liquids might be a potential candidate in flexible/foldable/stretchable electronics. The new concept of polymerizable liquid can be extended to other functional features suitable for futuristic applications.

10aEnergy Transfer10apolymerization10aSolvent-Free Organic Liquids10aThin-Film10aWhite Light1 aWakchaure, Vivek, Chandrakan1 aVeer, Sairam, Dnyaneshwa1 aNidhankar, Aakash, D.1 aKumar, Viksit1 aNarayanan, Aswini1 aBabu, Sukumaran, Santhosh uhttps://library.ncl.res.in/content/polymerizable-solvent-free-organic-liquids-new-approach-large-area-flexible-and-foldable03770nas a2200169 4500008004100000022001400041245010300055210006900158260000800227300001200235490000700247520312200254100003303376700003103409700003003440856013003470 2024 eng d a0001-484200aSolvent-free organic liquids: an efficient fluid matrix for unexplored functional hybrid materials0 aSolventfree organic liquids an efficient fluid matrix for unexpl cFEB a670-6840 v573 a

The invention of solvent-free organic liquids (SOLs) was serendipitous. However, the curiosity-driven research in the later stage delivered new soft materials with exciting optical, and optoelectronic properties along with appealing physical characteristics suitable for the futuristic applications. A slight change in the molecular design resulted in a drastic change in the physical state of molecules demonstrating monomer-like features in the bulk. The basic idea of core isolation has been successful in delivering new SOLs with attractive functional properties. The unique fluid matrix associated with SOLs offers a tremendous opportunity for making hybrid materials by simple mixing. The chance to study the fundamentally important electron transfer, energy transfer, charge transfer interactions, triplet-state emissions, and even detailed NMR experiments in the solvent-free neat state is the major attraction of SOLs. Usually, solvents and their polarity control such molecular properties, and in the case of SOLs, it avoids the use of solvents to study such fundamentally important properties. Besides, SOLs protect the triplet emitters and excited state processes involving triplet states from quenchers and make the analysis possible under ambient conditions. Our effort in this direction was focused on tuning the ground and excited state properties by transforming conventional organic molecules to SOLs and further value addition by preparing the hybrid SOLs. We developed a series of hybrid SOLs, exploring room-temperature phosphorescence, thermally activated delayed fluorescence, charge or energy transfer between donor and acceptor SOLs, selective explosive sensing, etc. A slight variation in the chemical structure or optoelectronic properties of the individual components imparted exciting optical features for the hybrid SOLs. It includes nonemissive charge transfer, tunable emission exciplex, room temperature phosphorescence, and thermally activated delayed fluorescence SOLs. The liquid matrix of donor SOLs accommodated varying amounts of acceptor SOLs to tune the ground and excited state features. In all examples of donor-acceptor-based hybrid SOLs, even a low amount of acceptor, such as a donor-acceptor ratio of 1000:1, can cause pronounced optical properties. Hence, the evaluation of the optical properties of SOLs, especially, in the absence of solvents is so special that it avoids the interference of solvent molecules. Still, the major drawback of SOLs remains unsolved until we report polymerizable SOLs. Although a large variety of SOLs have been reported in the literature, the long-lasting problem of surface stickiness of SOLs was resolved by polymerizable SOLs. It enabled the development of flexible, foldable, and stretchable large-area luminescent films suitable for lighting and display devices. In this Account, we summarize our work on SOLs, hybrid SOLs, polymerizable SOLs, and the application of SOLs in selective sensing of explosives. Finally, an outlook on the feasibility of luminescent polymerizable SOLs in futuristic applications is provided.

1 aWakchaure, Vivek, Chandrakan1 aChannareddy, Goudappagouda1 aBabu, Sukumaran, Santhosh uhttps://library.ncl.res.in/content/solvent-free-organic-liquids-efficient-fluid-matrix-unexplored-functional-hybrid-materials