Electrochemistry of binary and mixed-ligand copper(II) complexes with pyrazineand dicyanamide bridging ligands in aqueous medium

The binary copper(II) complexes, viz., [Cu(II) (pyz)n(H2O)n] (1), and [Cu(II)(dca)n(H2O)n] (2), and, mixed ligandcomplex, [Cu(II) (dca)n(pyz)n]. nH2O (3), containing pyrazine (pyz) and dicyanamide (dca) bridging ligands (where n isnumber of ligand attached and it could be 1 to 6 ) are formed in aqueous medium. The electrochemical behavior of binarycomplexes in 1:1, 1:2 and 1:10 (Cu : pyz/dca) molar ratios and mixed ligand complex in 1: 1 :1 and 1:2:1 (Cu:dca:pyz)molar ratios have been carried out by cyclic voltammetry. The binary complex 1 undergoes a quasi-reversible singleelectronredox process (Cu2+/+), while the binary complex 2 exhibits a totally irreversible reduction peak involving twoelectrons corresponding to Cu2+/0 change. The reduction potential becomes positive with increasing concentration of pyz/ordca, clearly indicating that reduction becomes easier with increasing concentration of ligand in binary complexes. Themixed ligand complex 3 involving pyz and dca bridging ligands shows an irreversible reduction peak assigned to Cu2+/0electrode reactions. The UV-vis spectral properties of all the binary and mixed ligand complexes have been studied inaqueous medium

Electro-catalyzed cynoarylmethylation of isatin for synthesis of 3-hydroxy-3-cynomethyl oxindole derivatives

An efficient and economical method has been developed for synthesis of 3-substituted oxindole by using electrochemically induced condensation of various N-substituted isatin, phenyl acetonitrile

Electrochemistry of binary and mixed-ligand copper(II) complexes with pyrazine and dicyanamide bridging ligands in aqueous medium

585-591The binary copper(II) complexes, viz., [Cu(II) (pyz)n(H2O)n] (1), and [Cu(II)(dca)n(H2O)n] (2), and, mixed ligand complex, [Cu(II) (dca)n(pyz)n]. nH2O (3), containing pyrazine (pyz) and dicyanamide (dca) bridging ligands (where n is number of ligand attached and it could be 1 to 6 ) are formed in aqueous medium. The electrochemical behavior of binary complexes in 1:1, 1:2 and 1:10 (Cu : pyz/dca) molar ratios and mixed ligand complex in 1: 1 :1 and 1:2:1 (Cu:dca:pyz) molar ratios have been carried out by cyclic voltammetry. The binary complex 1 undergoes a quasi-reversible single-electron redox process (Cu2+/+), while the binary complex 2 exhibits a totally irreversible reduction peak involving two electrons corresponding to Cu2+/0 change. The reduction potential becomes positive with increasing concentration of pyz/or dca, clearly indicating that reduction becomes easier with increasing concentration of ligand in binary complexes. The mixed ligand complex 3 involving pyz and dca bridging ligands shows an irreversible reduction peak assigned to Cu2+/0 electrode reactions. The UV-vis spectral properties of all the binary and mixed ligand complexes have been studied in aqueous medium

Electro-catalyzed cynoarylmethylation of isatin for synthesis of 3-hydroxy-3-cynomethyl oxindole derivatives

31-37An efficient and economical method has been developed for synthesis of 3-substituted oxindole by using electrochemically induced condensation of various N-substituted isatin, phenyl acetonitrile

Electro-catalyzed cynoarylmethylation of isatin for synthesis of 3-hydroxy-3-cynomethyl oxindole derivatives

31-37An efficient and economical method has been developed for synthesis of 3-substituted oxindole by using electrochemically induced condensation of various N-substituted isatin, phenyl acetonitrile

Wet chemical etching induced stress relaxed nanostructures on polar & non-polar epitaxial GaN films

We report formation of aligned nanostructures on epitaxially grown polar and nonpolar GaN films via wet chemical (hot H3PO4 and KOH) etching. The morphological evolution exhibited stress relaxed faceted nanopyramids, flat/trigonal nanorods and porous structures with high hydrophilicity and reduced wettability. The nanostructured films divulged significant suppression of defects and displayed an enhanced intensity ratio of the near band edge emission to the defect band. Extensive photoemission analysis revealed variation in oxidation state along with elimination of OH- and adsorbed H2O molecules from the chemically modified surfaces. Fermi level pinning, and alteration in the surface polarity with substantial changes in the electron affinities were also perceived. The temperature dependent currentvoltage analysis of the nanostructured surfaces displayed enhancement in current conduction. The in-depth analysis demonstrates that the chemically etched samples could potentially be utilized as templates in the design/growth of III-nitride based high performance devices