Development of 1‐Hydroxy‐2(1H)‐quinolone‐Based Photoacid Generators and Photoresponsive Polymer Surfaces

A new class of carboxylate and sulfonate esters of 1‐hydroxy‐2(1H)‐quinolone has been demonstrated as nonionic photoacid generators (PAGs). Irradiation of carboxylates and sulfonates of 1‐hydroxy‐2(1H)‐quinolone by UV light (λ≥310 nm) resulted in homolysis of weak N? O bond leading to efficient generation of carboxylic and sulfonic acids, respectively. The mechanism for the homolytic N? O bond cleavage was supported by time‐dependent DFT calculations. Photoresponsive 1‐(p‐styrenesulfonyloxy)‐2‐quinolone–methyl methacrylate (SSQL‐MMA) and 1‐(p‐styrenesulfonyloxy)‐2‐quinolone–lauryl acrylate (SSQL‐LA) copolymers were synthesized from PAG monomer 1‐(p‐styrenesulfonyloxy)‐2‐quinolone, and subsequently controlled surface wettability was demonstrated for the above‐mentioned photoresponsive polymers.     

Enhancement of H2 uptake via fluorination but not lithiation for Zn4N8 and Zn4N6O type clusters

The introduction of fluorinated aryls at zinc in Zn(4)N(8)-type (and to a lesser extent Zn(4)N(6)O) cages led to enhanced H(2) uptake. Lithium alkoxides have been shown to link such cages (non-fluorinated), but showed no substantial improvement in uptake.     

Development of 1-Hydroxy-2(1H)-quinolone-Based Photoacid Generators and Photoresponsive Polymer Surfaces

A new class of carboxylate and sulfonate esters of 1-hydroxy-2(1H)-quinolone has been demonstrated as nonionic photoacid generators (PAGs). Irradiation of carboxylates and sulfonates of 1-hydroxy-2(1H)-quinolone by UV light (λ≥310?nm) resulted in homolysis of weak N?O bond leading to efficient generation of carboxylic and sulfonic acids, respectively. The mechanism for the homolytic N?O bond cleavage was supported by time-dependent DFT calculations. Photoresponsive 1-(p-styrenesulfonyloxy)-2-quinolone-methyl methacrylate (SSQL-MMA) and 1-(p-styrenesulfonyloxy)-2-quinolone-lauryl acrylate (SSQL-LA) copolymers were synthesized from PAG monomer 1-(p-styrenesulfonyloxy)-2-quinolone, and subsequently controlled surface wettability was demonstrated for the above-mentioned photoresponsive polymers.     

One pot synthesis of RGO/PbS nanocomposite and its near infrared photoresponse study

We report the synthesis and characterization of lead sulfide (PbS) decorated reduced graphene oxide (RGO) nanocomposite materials. The materials were synthesized in a one-step solvothermal reaction where the reduction of graphene oxide, synthesis of PbS nanoparticle and decoration of PbS onto RGO were done simultaneously. Structural characterizations reveal that PbS nanoparticles are highly crystalline and a strong interaction exists between RGO and PbS. We also demonstrate fabrication of a near infrared (NIR) photo detector using RGO/PbS nanocomposite film.     

A Dark Energy Model with Generalized Uncertainty Principle in the Emergent, Intermediate and Logamediate Scenarios of the Universe

This work is motivated by the work of Kim et al. (Mod. Phys. Lett. A 23:3049, 2008), which considered the equation of state parameter for the new agegraphic dark energy based on generalized uncertainty principle coexisting with dark matter without interaction. In this work, we have considered the same dark energy interacting with dark matter in emergent, intermediate and logamediate scenarios of the universe. Also, we have investigated the statefinder, kerk and lerk parameters in all three scenarios under this interaction. The energy density and pressure for the new agegraphic dark energy based on generalized uncertainty principle have been calculated and their behaviors have been investigated. The evolution of the equation of state parameter has been analyzed in the interacting and non-interacting situations in all the three scenarios. The graphical analysis shows that the dark energy behaves like quintessence era for logamediate expansion and phantom era for emergent and intermediate expansions of the universe.     

Generalized second law of thermodynamics for FRW cosmology with power-law entropy correction

In this work, we have considered the power-law correction of entropy on the horizon. If the flat FRW Universe is filled with the n components fluid with interactions, the GSL of thermodynamics for apparent and event horizons have been investigated for equilibrium and non-equilibrium cases. If we consider a small perturbation around the de Sitter spacetime, the general conditions of the validity of GSL have been found. Also if a phantom dominated Universe has a pole-like type scale factor, the validity of GSL has also been analyzed. Further we have obtained constraints on the power-law parameter α in the phantom and quintessence dominated regimes. Finally we obtain conditions under which GSL breaks down in a cosmological background.     

First mixed hydrazide/hydroxylamide metal aggregates

The first organometallic clusters of mixed hydrazide/hydroxylamide clusters of zinc, [Zn(MeZn)(4)(HNNMe(2))(2)(ONEt(2))(4)] and {Zn(EtZn)(4)[HNN(CH(2))(5)](2)(ONEt(2))(4)} were synthesized in one-pot synthesis protocols from dialkylzinc solutions, substituted hydrazines and N,N-diethylhydroxylamine; competing for the Zn atoms, the different binding properties of hydrazide and hydroxylamide ligands in these heteroleptic clusters are discussed.     

Interaction Between DBI-Essence and Other Dark Energies

The present work considers interaction between DBI-essence and other candidates of dark energies like modified Chaplygin gas, hessence, tachyonic field, and new agegraphic dark energy. The potentials of the fields have been reconstructed under interaction and their evolutions have been viewed against cosmic time t and scalar field φ. Equation of state parameters have also been obtained. The nature of potentials and the equation of state parameters of the dark energies have been found graphically in presence of interaction (both small and large interaction).     

Surface optical phonon modes in ternary aligned crystalline InGaN/GaN multi‐quantum‐well nanopillar arrays

The optical properties of focused ion beam‐engraved, perfectly aligned and spatially controlled multi‐quantum‐well (MQW) InGaN/GaN nanopillars were investigated. Crystalline MQW nanopillars with a diameter of 30–95 nm and high aspect ratios (7:1–16:1) showed a maximum of three‐fold enhancement in emission intensity per unit active area. A light‐emitting contour map of Taiwan is drawn with a nanopillar structure to demonstrate the site control of the technique adopted in the present study. Raman scattering studies were used to characterize the newly created surfaces. Unknown peaks in GaN and InGaN nanostructures are identified for surface optical (SO) phonon modes with proper assignments of wave vectors using multiple excitations, and the SO mode for the ternary phase is reported for the first time. Copyright © 2009 John Wiley & Sons, Ltd.     

Oxovanadium(V) complexes incorporating tridentate aroylhydrazoneoximes: Synthesis, characterizations and antibacterial activity

Some new oxovanadium(V) complexes, [VOL^1-3(OEt)(EtOH)] (1-3), have been reported, which were obtained from the reaction of the Schiff bases H₂L^1-3 (where H₂L¹ = the salicylhydrazone of diacetyl monoxime; H₂L² = the 4-methoxy salicylhydrazone of diacetyl monoxime and H₂L³ = the 4-hydroxy salicylhydrazone of diacetyl monoxime) with VO(acac)₂ in a 1:1 molar ratio. Three 4-R-aroylhydrazoneoximes (V) have been used as ligands in the present study, differing in the inductive effect of the substituent R (R = H, OCH₃ and OH), in order to observe their influence, if any, on the redox potentials and biological activity of the complexes. All the synthesized ligands and metal complexes were successfully characterized by elemental analysis, IR, UV-Vis and NMR spectroscopy. An X-ray diffraction study of [VOL¹(OEt)(EtOH)] (1) reveals that the metal center has a distorted octahedral O₅N coordination sphere, where the O,N,O donor ligand and the ethoxo group constitute a satisfactory O₃N basal plane. Cyclic voltammetry of the complexes show a quasi-reversible cyclic voltammetric response in the potential range 0.29-0.36 V involving a single electron V(V)-V(IV) reduction. The complexes have also been screened for their antibacterial activity against Escherichia coli, Bacillus, Proteus and Klebsiella. Minimum inhibitory concentrations of these complexes and the antibacterial activities indicate compound 1 as the potential lead molecule for drug design.