@article {43166, title = {Fluoride-mediated dephosphonylation of α-diazo-β-carbonyl phosphonates}, journal = {Organic Letters}, volume = {19}, year = {2016}, month = {DEC}, pages = {372 - 375}, abstract = {The 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).}, author = {Phatake, Ravindra S. and Mullapudi, Venkanna Babu and Wakchaure, Vivek Chandrakant and Ramana, Chepuri V.} } @article {43852, title = {Cascade energy transfer and tunable emission from nanosheet hybrids: locating acceptor molecules through chiral doping}, journal = {Chemical Communications}, volume = {53}, year = {2017}, month = {JUL}, pages = {7072-7075}, type = {Article}, abstract = {Light 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.}, doi = {10.1039/c7cc02994b}, author = {Goudappagouda and Wakchaure, Vivek Chandrakant and Ranjeesh, Kayaramkodath Chandran and Abhai, Chalona Antony Ralph and Babu, Sukumaran Santhosh} } @article {46064, title = {Boron-conjugated pyrenes as fluorescence-based molecular probes and security markers}, journal = {ChemPlusChem}, year = {2019}, month = {JUL}, type = {Article}, abstract = {

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.

}, keywords = {boron, carbohydrates, mechanoluminescence, pyrene, sensors}, issn = {2192-6506}, doi = {10.1002/cplu.201900280, Early Access Date = JULY, Early Access Year = 2019}, author = {Wakchaure, Vivek Chandrakant and Das, Tamal and Babu, Sukumaran Santhosh} } @article {46297, title = {Cascade energy transfer and tunable emission from nanosheet hybrids: locating acceptor molecules through chiral doping (vol 53, pg 7072, 2017)}, journal = {Chemical Communications}, volume = {55}, year = {2019}, month = {JUN }, pages = {6462-6462}, type = {Correction}, abstract = {

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

}, issn = {1359-7345}, doi = {10.1039/c9cc90228g}, author = {Goudappagouda and Wakchaure, Vivek Chandrakant and Ranjeesh, Kayaramkodath Chandran and Abhai, Chalona Antony Ralph and Babu, Sukumaran Santhosh} } @article {46204, title = {Charge transfer liquid: a stable donor-acceptor interaction in the solvent-free liquid state}, journal = {Chemical Communications}, volume = {55}, year = {2019}, month = {AUG}, pages = {9371-9374}, type = {Article}, abstract = {

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.

}, doi = {10.1039/c9cc03671g}, author = {Wakchaure, Vivek Chandrakant and Pillai, Lekshmi, V and Goudappagouda and Ranjeesh, Kayaramkodath Chandran and Chakrabarty, Suman and Ravindranathan, Sapna and Rajamohanan, Pattuparambil R and Babu, Sukumaran Santhosh} } @article {46348, title = {Imidazole-linked crystalline two-dimensional polymer with ultrahigh proton-conductivity}, journal = {Journal of the American Chemical Society}, volume = {141}, year = {2019}, month = {SEP}, pages = {14950-14954}, type = {Article}, abstract = {

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.

}, issn = {0002-7863}, doi = {10.1021/jacs.9b06080}, author = {Ranjeesh, Kayaramkodath Chandran and Ilathvalappil, Rajith and Veer, Sairam Dnyaneshwar and Peter, Joseph and Wakchaure, Vivek Chandrakant and Goudappagouda and Raj, K. Vipin and Kurungot, Sreekumar and Babu, Sukumaran Santhosh} } @article {47501, title = {Excimer to exciplex transition through realization of donor-acceptor interactions in luminescent solvent-free liquids}, journal = {Nanoscale}, volume = {13}, year = {2021}, month = {JUN}, pages = {10780-10784}, type = {Article}, abstract = {Luminescent 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 {\textquoteleft}{\textquoteleft}exciplex liquid{\textquoteright}{\textquoteright} 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.}, issn = {2040-3364}, doi = {10.1039/d1nr02190g, Early Access Date = MAY 2021}, author = {Wakchaure, Vivek Chandrakant and Goudappagouda and Das, Tamal and Ravindranathan, Sapna and Babu, Sukumaran Santhosh} } @article {47761, title = {Donor-acceptor based solvent-free organic liquid hybrids with exciplex emission and room temperature phosphorescence}, journal = {Chemical Communications}, volume = {58}, year = {2022}, month = {FEB }, pages = {1998-2001}, type = {Article}, abstract = {Solvent-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.}, issn = {1359-7345}, doi = {10.1039/d1cc07082g}, author = {Wakchaure, Vivek Chandrakant and Veer, Sairam D. and Nidhankar, Aakash D. and Goudappagouda and Nayak, Rashmi and Asokan, Kiran and Ravindranathan, Sapna and Babu, Sukumaran Santhosh} }