01587nas a2200193 4500008004100000245009400041210006900135260000800204300001600212490000700228520085000235653007801085100002301163700001401186700002601200700002401226700002201250856012101272 2016 eng d00aLewis acid catalyzed selective reactions of donor-acceptor cyclopropanes with 2-naphthols0 aLewis acid catalyzed selective reactions of donoracceptor cyclop cAUG a10061-100640 v553 a

Lewis acid-catalyzed reactions of 2-substituted cyclopropane 1,1-dicarboxylates with 2-naphthols is reported. The reaction exhibits tunable selectivity depending on the nature of Lewis acid employed and proceed as a dearomatization/rearomatization sequence. With Bi(OTf)(3) as the Lewis acid, a highly selective dehydrative [3+2] cyclopentannulation takes place leading to the formation of naphthalene-fused cyclopentanes. Interestingly, engaging Sc(OTf)(3) as the Lewis acid, a Friedel-Crafts-type addition of 2-naphthols to cyclo-propanes takes place, thus affording functionalized 2-naphthols. Both reactions furnished the target products in high regioselectivity and moderate to high yields.

10aannulations; arenes; Lewis acids; reaction mechanisms; small ring systems1 aKaicharla, Trinadh1 aRoy, Tony1 aThangaraj, Manikandan1 aGonnade, Rajesh, G.1 aBiju, Akkattu, T. uhttps://library.ncl.res.in/content/lewis-acid-catalyzed-selective-reactions-donor-acceptor-cyclopropanes-2-naphthols01105nas a2200181 4500008004100000245013000041210006900171260000800240300001400248490000700262520040700269100002600676700002200702700002800724700002400752700002200776856012500798 2017 eng d00aLewis acid catalyzed cascade annulation of alkynols with alpha-ketoesters: a facile access to gamma-spiroketal-gamma-lactones0 aLewis acid catalyzed cascade annulation of alkynols with alphake cJUN a6641-66440 v533 aA novel Lewis acid catalyzed intermolecular cascade annulation of alkynols with alpha-ketoesters has been developed. This simple and efficient cascade annulation proceeds through a 5-exo-dig cyclization of alkynols followed by annulation with alpha-ketoester to provide a wide variety of unsaturated gamma-spiroketal-gamma-lactones (1,6-dioxaspiro[4.4]non-3-en-2-ones) related to many natural products.1 aKambale, Digambar, A.1 aThorat, Sagar, S.1 aPratapure, Madhukar, S.1 aGonnade, Rajesh, G.1 aKontham, Ravindar uhttps://library.ncl.res.in/content/lewis-acid-catalyzed-cascade-annulation-alkynols-alpha-ketoesters-facile-access-gamma01468nas a2200181 4500008004100000245015200041210006900193260000800262300001000270490000800280520075300288100001801041700002501059700002701084700002301111700002401134856012801158 2018 eng d00a Lithium hydride as an efficient reagent for the preparation of 1,2-anhydro inositols: does the reaction proceed through 'axial rich' conformation?0 aLithium hydride as an efficient reagent for the preparation of 1 cJUL a32-360 v4633 ascyllo-Inositol derived 1,2-trans-diequatorial halohydrins can be efficiently converted to the corresponding epoxides in the presence of lithium hydride. The structure of one of the epoxides was determined by single crystal X-ray diffraction analysis. This provides a potential route for the preparation of ring modified inositol derivatives. DFT calculations suggest that this epoxide formation could be proceeding through the intermediacy of the cyclohexane ring-inverted axial-rich conformer (1,2-trans-diaxial halohydrin). This is supported by the results of DFT calculations on the formation of inositol orthoformate, where the product is locked in the axial-rich conformation, while the starting inositol has the equatorial-rich conformation.1 aSarkar, Nitai1 aSardessai, Richa, S.1 aShashidhar, Mysore, S.1 aTamboli, Majid, I.1 aGonnade, Rajesh, G. uhttps://library.ncl.res.in/content/lithium-hydride-efficient-reagent-preparation-12-anhydro-inositols-does-reaction-proceed02692nas a2200265 4500008004100000022001400041245009300055210006900148260000800217300001400225490000800239520180600247100003102053700002702084700002202111700001802133700002202151700002202173700002002195700002002215700002702235700002402262700002002286856012002306 2020 eng d a1932-744700aLigand structure directed dimensionality reduction (2D -> 1D) in lead bromide perovskite0 aLigand structure directed dimensionality reduction 2D 1D in lead cJAN a1888-18970 v1243 a

Low dimensional (2D, 1D) lead halide perovskites are currently attracting huge research interest due to their enabling properties. Demonstrating synthetic control on the dimensionality/ structure of these perovskites is highly challenging. Dimensionality in these perovskites is largely dictated by the nature/structure and composition of the incorporating ligands and the utilized synthetic conditions. Here, we demonstrate chemical composition based control on reduction of dimensionality (2D -> 1D) for lead bromide perovskite utilizing 2-(2-aminoethyl)isothiourea dihydrobromide as a common precursor ligand (Isothio Bromide). Controlling the hydrothermal reaction parameters (temperature, time) at a fixed precursor ratio affords corner-shared, contorted 2D sheet perovskite and corner-shared, contorted, chiral 1D chain perovskite. Such dimensionality reduction leads to contrasting photophysical properties: 1D chain perovskite shows long-lived and self-trapped broad band emission, whereas 2D perovskite shows short-lived, band edge emission with a long tail. Mechanistic studies and single crystal structure analysis reveal the incorporation of the utilized precursor ligand (Isothio Bromide) in 2D perovskite. Surprisingly, the 1D perovskite is found to be chiral (P2(1) space group) incorporating 2-(2-aminoethyldisulfanyl)ethanamine and ammonium ions as the achiral ligands generated in situ due to hydrothermal cleavage of the precursor (Isothio Bromide) ligand. Such structural and compositional change of the ligands, which manifests a different hydrogen bonding network in the resultant perovskite structure, plays a decisive role in dictating the final molecular formula and dimensionality/structure of the perovskite which largely controls their photophysical properties.

1 aBakthavatsalam, Rangarajan1 aHaris, Muhammed, P. U.1 aShaikh, Samir, R.1 aLohar, Amruta1 aMohanty, Ashutosh1 aMoghe, Dhanashree1 aSharma, Shivani1 aBiswas, Chinmoy1 aRaavi, Sai, Santhosh K1 aGonnade, Rajesh, G.1 aKundu, Janardan uhttps://library.ncl.res.in/content/ligand-structure-directed-dimensionality-reduction-2d-1d-lead-bromide-perovskite02039nas 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-temperature01054nas a2200217 4500008004100000022001400041245008100055210006900136260000800205300001600213490000700229520034800236100001700584700002000601700002000621700002500641700002400666700001700690700001900707856011000726 2022 eng d a1359-734500aLuminescent magnesium complexes with intra- and inter-ligand charge transfer0 aLuminescent magnesium complexes with intra and interligand charg cOCT a11843-118460 v583 a

Herein, we report two 2,2'-pyridylpyrrolide (PyPyrH) ligand supported magnesium complexes (1 and 2), which demonstrate bright luminescence with a quantum yield of 22% and 14% in the solid state, respectively. Theoretical calculations reveal that their emissive properties originate from the intra- and inter-ligand charge transfer.

1 aKumar, Rohit1 aPahar, Sanjukta1 aChatterjee, Joy1 aDash, Soumya, Ranjan1 aGonnade, Rajesh, G.1 aVanka, Kumar1 aSen, Sakya, S. uhttps://library.ncl.res.in/content/luminescent-magnesium-complexes-intra-and-inter-ligand-charge-transfer