Open-shell phenalenyl chemistry started more than half a century back, and the first solid-state phenalenyl radical was realized only 15 years ago highlighting the synthetic challenges associated in stabilizing carbon-based radical chemistry, though it has great promise as building blocks for molecular electronics and multifunctional materials. Alternatively, stable closed-shell phenalenyl has tremendous potential as it can be utilized to create an in situ open-shell state by external spin injection. In the present study, we have designed a closed-shell phenalenyl-based iron(III) complex, Fe(III)(PLY)3 (PLY-H = 9-hydroxyphenalenone) displaying an excellent electrocatalytic property as cathode material for one compartment membraneless H2O2 fuel cell. The power density output of Fe(III)(PLY)3 is nearly 15-fold higher than the structurally related model compound Fe(III)(acac)3 (acac = acetylacetonate) and nearly 140-fold higher than an earlier reported mononuclear Fe(III) complex, Fe(III)(Pc)Cl (Pc = pthalocyaninate), highlighting the role of switchable closed-shell phenalenyl moiety for electron-transfer process in designing electroactive materials.

The hydrosilylation of olefins by a nickel(ii) catalyst assisted by a redox non-innocent phenalenyl (PLY) ligand is reported.

We have demonstrated that the nonbonding molecular orbital (NBMO) of the phenalenyl (PLY) cation can be used as a Lewis acid catalyst for different organic transformations. Detailed computational and spectroscopic studies for the aminolysis reaction of epoxide reveal that this catalysis works through a different mechanism, and the phenalenyl cation activates the amine moiety using its empty NBMO, which triggers the epoxide ring-opening reaction. It has been shown that the energy of the NBMO of PLY cation plays a key role in modulating the catalytic activity. This study establishes that the cationic state of phenalenyl unit is useful not only for construction of the spin memory device by external spin injection using its NBMO, but in addition, the same NBMO can act as an organic Lewis acceptor unit to influence the catalytic outcome of a homogeneous reaction.

Redox equivalent storage in the phenalenyl backbone towards catalytic multi-electron reduction.

We report unprecedented phase stability of cubic CsPbBr 3 quantum dots in ambient air obtained by using Br 2 as halide precursor. Mechanistic investigation reveals the decisive role of temperaturecontrolled in situ generated, oleylammonium halide species from molecular halogen and amine for the long term stability and emission tunability of CsPbX 3 (X ¼ Br, I) nanocrystals.High photoluminescence quantum yield (PL QY), narrow emission linewidth, tunable band gap, large diffusion lengths and low exciton binding energies are some of the key attributes of all-inorganic caesium lead halide perovskite nanocrystals (LHP NCs) i.e., CsPbX 3 , X ¼ I, Br, This novel class of NCs has been shown to be highly "defect tolerant", i.e. defect states are either shallow or localized in the valence or the conduction band. 1,2 Unlike conventional semiconductor NCs, the rigorous passivation of their surface via formation of core/shell structures or other methods is not required to achieve high QY. These LHP NCs are promising building blocks for light emitting diode, 3,4 solar cell, 5,6 laser, 7 photocatalysis 8 and detector. 9 Despite the recent surge of studies on CsPbX 3 perovskite NCs, a persisting drawback is their poor phase stability in ambient air. For example, cubic (a) "black" phase CsPbI 3 (E g ¼ 1.73 eV) perovskite NCs undergo rapid phase transformation to nonluminescent orthorhombic (d) "yellow" phase in ambient condition ( Fig. S1 †) leading to undesired changes of the band gap, optical and electrical properties. 6,10,11 Similarly, cubic (a) CsPbBr 3 (E g ¼ 2.25 eV) is unstable at ambient condition. 12 For successful integration of these materials into devices, the issue of long-term phase stability must thus be addressed. 6,13 Most of the reported strategies involve the use of additives such as halide salt, 12 phosphinic acid, 14 ammonium halide, 11 2,2 0 -iminodibenzoic acid 15 sulphides and metal ions 16 and polymers 5 or via special post-synthetic purication step. 6,10 Herein, we report the rst synthesis of highly stable, cubic a-CsPbBr 3 perovskite NCs using Br 2 as an independent halide precursor. In a typical synthesis, lead acetate is dissolved in 1-octadecene in the presence of oleyl amine (OAm) and oleic acid (OA). To this solution, Br 2 (warning: handle the liquid Br 2 in fume hood, Br 2 vapors are toxic) and caesium oleate solutions (both dissolved in ODE) are sequentially added. Phase stability and emission colour tunability are achieved by controlling the reaction temperature (75-200 C) and amount of Br 2 (0.6-1.2 mmol) under air-free synthetic condition (cf. ESI; Experimental section †). The "three-precursor" nature 16-18 of our synthetic scheme allows for independent tuning of the amount of the individual elements viz., Cs + , Pb 2+ and X À ions and in turn, allows for the precise control over the surface chemistry. 17 Highly crystalline, monodisperse 7.62 AE 1.0 nm sized cubic a-CsPbBr 3 NCs (Fig. 1a) were synthesised under optimized conditions using Cs : Pb : Br 2 ratio of 1 : 1 : 6 at 200 C. Highresol...

Metal−organic frameworks (MOFs) are extensively used in catalysis due to their robust structure, well-defined periodic reaction centers, and high porosity. We report Cu 3 (BTC) 2 •(H 2 O) 3 (HKUST-1) as an efficient heterogeneous catalyst for aziridination of alkene and ring-opening reaction of activated aziridines. Furthermore, we demonstrate that the transfer of a nitrogen group from PhINTs to olefins and its analogue to give aziridines takes place at the coordinatively unsaturated Cu(II) site of Cu 3 (BTC) 2 −MOF; however, the ring opening of activated aziridines is controlled by the Cu(II) Lewis acid site, and generation of coordinative unsaturation by thermal activation of the MOF is not necessarily important. The key advantage of this catalytic approach is the direct formation of C−C, C−N, C−O, and C−S bonds yielding β-aryl sulfonamide derivatives through a simultaneous aziridination ring-opening reaction of the alkene in one pot using a single catalyst.

Lead halide perovskite (LHP) based colloidal quantum dots (CQDs) have tremendous potential for photocatalysis due to their exceptional optical properties.

Hereinw er eport the synthesis of an ew abnormal N-heterocyclic carbene( aNHC)-based ligand and its use in synthesizing an acetate bridged C À Ha ctivated palladium dimer (1). In complex 1, the carbenel igand displays an abnormal mode of binding with the palladium(II) ion. We used complex 1 as ac atalyst for the oxidative Heck coupling reac-tion of arylboronic acids with electron-deficient as well as electron-rich olefins at ambient temperature in water to produce selectively the b-arylated products in good to excellent yields. Synthesis of Complex 1Undera na rgon atmosphere,a5 0-mL Schlenk flask was charged with Pd(OAc) 2 (224 mg, 1mmol), L 1 HI (438 mg, 1mmol), and 1,4-dioxane( 15 mL). Ther eaction mixture was heated to 80 8 8Cf or 8h.A fter cooling to room temperature,a ll volatiles were removed under reduced pressure from the reaction mixture.C omplex 1 was obtained by recrystallization from CH 2 Cl 2 /hexane as yellow crystals;y ield: 571 mg (0.6 mmol, 60%);m p2 98-303 8 8C. 1 HNMR (400 MHz, CDCl 3, 25 8 8C, TMS): d = 7.67 (t, J = 7.6 Hz, 1H), Scheme 5. Chemoselectivity study with catalyst 1.