Publications by authors named "George Rajendra Kumar"

A simple, low-cost, and environmentally benign process for synthesizing nanostructured NiO/NiAlO on multiple kinds of carbon nanostructures (CNS) is presented. This method develops polylactic acid (PLA) based waste plastic materials for the producing CNS. These composites (NiO@NiAlO/CNS) were examined as potential electrodes in supercapacitors (SC) as they exhibit good charge/discharge reversibility and provide adequate specific capacitance values with a maximum being 1984 F/g at 0.

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Stoichiometric carbon dioxide reduction to highly reduced C1 molecules, such as formic acid (2e ), formaldehyde (4e ), methanol (6e ) or even most-reduced methane (8e ), has been successfully achieved by using organosilanes, organoboranes, and frustrated Lewis Pairs (FLPs) in the presence of suitable catalyst. The development of renewable organohydride compounds could be the best alternative in this regard as they have shown promise for the transfer of hydride directly to CO . Reduction of CO by two electrons and two protons to afford formic acid by using renewable organohydride molecules has recently been investigated by various groups.

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We report a series of room temperature phosphorescent compounds 1-6 composed of triarylborane (TAB) and cyclometallated iridium complexes. The optical characteristics such as energy of transition and luminescence quantum yield of these compounds can be conveniently fine-tuned by judiciously varying the cyclometallating ligand and the spacer between boron and iridium centers. Compounds 1-6 exhibit bright phosphorescence with the emission color ranging from green to red under a N2 atmosphere.

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A new series of luminescent cyclometalated platinum complexes with triarylborane-functionalized acetylacetonate ligands is reported. The complexes exhibit solid state luminescence and phosphorescence under ambient conditions. The luminescence color can be tuned from green to red by varying the cyclometalating ligand [2-phenylpyridine (for 1 and 2), 2-thiophenylpyridine (for 3 and 4), 2-thianapthenylpyridine (for 5 and 6)].

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The design, synthesis and aggregation-induced emission properties of a new series of triarylborane-oligothiophene-dicyanovinyl (DCV) conjugates 4-6 (A-D-A' type molecular configuration) are reported. The optical properties of 4-6 can be modulated by judiciously varying the number of thiophene units between electron deficient boryl and dicyanovinyl units. Compound 6 with terthiophene spacer showed highly red-shifted absorption and emission compared to 5 and 4 with bithiophene and monothiophene spacers, respectively.

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The design and synthesis of two structurally close and complementarily fluorescent boron based molecular siblings 2 and 3 are reported. The luminescence properties of individual triads are modulated to complement each other by controlling the intramolecular energy transfer in 2 and 3. The binary mixture of 2 and 3 emits white-light.

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Three new triarylborane conjugated dicyanovinyl chromophores (Mes2B-π-donor-DCV); donor: N-methyldiphenylamine () and triphenylamine ( and [with two BMes2 substitutions]) of type A-D-A (acceptor-donor-acceptor) are reported. Compounds exhibit intense charge transfer (CT) absorption bands in the visible region. These absorption peaks are combination CT bands of the amine donor to both the BMes2 and DCV units.

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Two new dicyanovinyl (DCV) functionalized triarylboranes (Mes2B-π-spacer-DCV, for 1: π-spacer = C6H4, for 2: π-spacer = 2,3,5,6-tetramethyl-phenyl) are reported. The molecular structures of 1 and 2 are similar except for the spacer which connects the boryl and DCV units. This small structural perturbation induces drastic changes in the optical properties of 1 and 2.

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A facile synthetic route for a new class of organoborane compounds (Mes)2B-arene-acacH and (Mes)2B-arene-acacBF2 (Mes = mesityl and arene = C6H4 or C6Me4) is reported. The new dyads exhibit intriguing photophysical properties. A small structural change in spacer connecting the two chromophores leads to fine tuning of photophysical properties.

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