01879nas a2200193   4500008004100000245011500041210007100156260000800227300001500235490000600250520119000256653001201446653001801458653002301476653002101499100001501520700001401535856013601549       2017                        eng d00aLess frustration, more Activity—theoretical insights into frustrated lewis pairs for hydrogenation catalysis0 aLess frustration more Activity—theoretical insights into frustra  cAUG  a 3013-30220 v93 aThe field of frustrated Lewis pair (FLP) chemistry has seen rapid development in only a few years. FLPs have performed most spectacularly in hydrogenation catalysis: a wide variety of FLP-based systems can catalyze the hydrogenation of a range of different substrates, including imines, enamines, ketones, alkynes, and alkenes. However, FLP-based hydrogenation catalysts are yet to match the efficiency of their transition-metal counterparts. The current investigation reveals an important aspect of FLPs that can be exploited to improve their efficiency, that is, the more sterically hindered the FLP catalyst is, the lower is its turnover frequency. Full quantum chemical calculations with DFT for a family of different, experimentally known hydrogenation FLP catalysts shows that superior FLP catalysts can be designed by reducing the frustration (by reducing the steric demand and acid/base strength) in the FLP. However, as lowering the steric demand without reduction in the frustration can result in unwanted side reactions, the design of the most efficient FLP catalysts depends on tuning the system so that both the steric demand and the frustration are reduced appropriately.10aBoranes10aHydrogenation10areaction mechanism10aSteric Hindrance1 aMane, M.V.1 aVanka, K.  uhttps://library.ncl.res.in/content/less-frustration-more-activity%E2%80%94theoretical-insights-frustrated-lewis-pairs-hydrogenation01703nas a2200205   4500008004100000245009500041210006900136260000800205300001500213490000700228520103600235100001301271700001301284700001601297700001401313700001701327700001401344700001701358856012201375       2017                        eng d00aOdd-even alternation in tautomeric porous organic cages with eceptional chemical stability0 aOddeven alternation in tautomeric porous organic cages with ecep  cFEB  a 2123-21260 v563 aAmine-linked (C-NH) porous organic cages (POCs) are preferred over the imine-linked (C= N) POCs owing to their enhanced chemical stability. In general, aminelinked cages, obtained by the reduction of corresponding imines, are not shape-persistent in the crystalline form. Moreover, they require multistep synthesis. Herein, a one-pot synthesis of four new amine-linked organic cages by the reaction of 1,3,5-triformylphloroglucinol (Tp) with different analogues of alkanediamine is reported. The POCs resulting from the odd diamine (having an odd number of -CH2 groups) is conformationally eclipsed, while the POCs constructed from even diamines adopt a gauche conformation. This odd-even alternation in the conformation of POCs has been supported by computational calculations. The synthetic strategy hinges on the concept of Schiff base condensation reaction followed by keto-enol tautomerization. This mechanism is the key for the exceptional chemical stability of cages and facilitates their resistance towards acids and bases.1 aBera, S.1 aBasu, A.1 aTothadi, S.1 aGarai, B.1 aBanerjee, S.1 aVanka, K.1 aBanerjee, R.  uhttps://library.ncl.res.in/content/odd-even-alternation-tautomeric-porous-organic-cages-eceptional-chemical-stability01878nas a2200277   4500008004100000022001400041245011600055210007100171260000800242300001400250490000700264520099100271653001901262653001501281653002801296653002601324653001101350100001301361700001401374700001601388700001401404700001301418700001401431700001601445856013901461       2019                        eng d  a1433-785100aC‐F bond activation by saturated NHC: mesoionic compound formation and its unprecedented adduct with B(C6F5)30 aC‐F bond activation by saturated NHC mesoionic compound formatio  cFEB  a2804-28080 v583 a<p>The reaction of SIPr, [1,3‐bis(2,6‐diisopropylphenyl)‐imidazolin‐2‐ylidene] (1), with C6F6 led to the formation of an unprecedented mesoionic compound (2). The formation of 2 is made accessible by deprotonation of the SIPr backbone with simultaneous elimination of HF. The C−F bond para to the imidazolium ring in 2 is only of 1.258(4) Å, which is the one of the shortest structurally authenticated C−F bonds known to date. The liberation of HF during the reaction is unequivocally proved by the addition of one more equivalent of SIPr, which leads to the imidazolium salt with the HF2− anion. To functionalize 2, the latter reacted with B(C6F5)3 to give an unusual donor–acceptor compound, where the fluoride atom from the C6F5 moiety coordinates to B(C6F5)3 and the carbanion moiety remains unaffected. Such coordination susceptibility of the fluoride atom of a nonmetallic system to a main‐group Lewis acid (Fnon‐metal→BR3) is quite unprecedented.</p>
10aC-F activation10acarbanions10aN-heterocyclic carbenes10astructure elucidation10aYlides1 aPait, M.1 aKundu, G.1 aTothadi, S.1 aKarak, S.1 aJain, S.1 aVanka, K.1 aSen, S., S.  uhttps://library.ncl.res.in/content/c%E2%80%90f-bond-activation-saturated-nhc-mesoionic-compound-formation-and-its-unprecedented-adduct01522nas a2200217   4500008004100000245009800041210006900139260000800208300001400216490000700230520079600237100001801033700001901051700002201070700002101092700001201113700001401125700001801139700001701157856013001174       2019                        eng d00aPaintable room-temperature phosphorescent liquid formulations of alkylated bromonaphthalimide0 aPaintable roomtemperature phosphorescent liquid formulations of   cFEB  a2284-22880 v583 aOrganic phosphors have been widely explored with an understanding that crystalline molecular ordering is a requisite for enhanced intersystem crossing. In this context, we explored the room‐temperature phosphorescence features of a solvent‐free organic liquid phosphor in air. While alkyl chain substitution varied the physical states of the bromonaphthalimides, the phosphorescence remained unaltered for the solvent‐free liquid in air. As the first report, a solvent‐free liquid of a long swallow‐tailed bromonaphthalimide exhibits room‐temperature phosphorescence in air. Doping of the phosphor with carbonyl guests resulted in enhanced phosphorescence, and hence a large‐area paintable phosphorescent liquid composite with improved lifetime and quantum yield was developed.1 aGoudappagouda1 aManthanath, A.1 aWakchaure, V., C.1 aRanjeesh, K., C.1 aDas, T.1 aVanka, K.1 aNakanishi, T.1 aBabu, S., S.  uhttps://library.ncl.res.in/content/paintable-room-temperature-phosphorescent-liquid-formulations-alkylated-bromonaphthalimide