Synthesis and Computational Investigations of Ruthenium(II) Complexes Containing Hydrazine Schiff Base Ligands

Pages

S. Kamalesu, K. Swarnalatha and R. Subramanian

DOI:

Published:

Abstract: Three new heteroleptic ruthenium(II) complexes containing hydrazine schiff base as ligands were synthesized and characterized by using elemental analysis, FT-IR, ¹H, ¹³C NMR, and mass spectroscopic techniques. FT-IR study showed that the substituted phenylhydrazine ligands behave as a monoanionic bidentate O and N donors (L) coordinate to ruthenium via the deprotonated phenolic oxygen and the azomethine nitrogen. They possess excellent thermal stabilities, evident from the thermal decomposition temperatures. Absorption, emission and electrochemical measurements were carried out and the structures of the synthesized complex were optimized using density functional theory (DFT). The molecular geometry, the highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO) energies, Mulliken atomic charges and molecular electrostatic potential (MEP) of the molecules are determined using B3LYP method and standard 6-311++G (d, p) basis set.

Pages 62-74

D.V. Schur, S. Yu. Zaginaichenko, T.N. Veziroglu, A. Veziroglu and M.T. Gabdullin

DOI: https://doi.org/10.6000/1929-5030.2017.06.02.2

Published: 19 June 2017

Abstract: The last thirty years scientists carried out an active search of universal parameter of solvent C60 for predicting the solubility of fullerenes. However, this parameter was not found up to these days. In this paper it has been found an explanation of the impossibility of detection of such parameter.

In present paper the features of the solubility of fullerene C60 molecules in nonpolar solvents have been studied. The molecule state diagram of the fullerene С60 molecules in solution at temperatures 265÷308 К and pressure range 1÷100 МPа, indicating the existence field of β- and γ-modifications, has been constructed.

Moreover, it has been shown that in the solutions of fullerenes C60 in the γ-state the solubility decreases with a rise in temperature since the chemical activity of fullerene molecule increases. For this reason during extraction procedure the temperature rise causes the value of extraction rate to increase, but solubility – to decrease, i.e. to diminish the concentration of fullerenes molecules in the solvent volume.

Keywords: Fullerene C₆₀ molecule, molecule diagram, colloidal solution, solubility isobar, solutions classification.

Synthesis of Stable Sols of Layered Titanate Nanoparticles using Dialysis and Applications for Thin Film Preparation
Pages 165-172
Chun Ming Wen, Takashi Kojima and Naofumi Uekawa

DOI: http://dx.doi.org/10.6000/1929-5030.2015.04.04.1

Published: 17 December 2015

Abstract: Sols with stable dispersion of layered titanate nanoparticles were prepared at 298 K using dialysis of a mixed solution of ethylene glycol, TiCl₃, ammonium carbonate, and H₂O₂. Raman spectra of the particles in the obtained sols showed Raman scattering peaks which can be assigned to a layered titanate structure. The stability of the obtained sols depended on the molar ratio of [ammonium carbonate] / [Ti ion]. The molar ratios of 3, 4, and 5 produced transparent yellow stable sols. Peptization of titanium hydroxide precipitate with H₂O₂ formed stable sols with dispersion of layered titanate nanoparticles, which had plate - shaped morphology. The obtained sols formed layered titanate thin films on glass substrates easily by drying the sols. Furthermore, when the layered titanate thin films were heated at 773 K for 1 h, anatase TiO₂ thin films were obtained with (101) orientation of crystallites and optical transparency.

Abstract: The mechanism and kinetics are developed for the free-radical nonbranched-chain initiated formation of ethylene glycol in methanol–formaldehyde solutions at formaldehyde concentrations of 0.1–3.1 mol dm–3 and temperatures of 373–473 K. The experimental concentrations of the free unsolvated form of formaldehyde are given at the different temperatures and total concentrations of formaldehyde in methanol. The experimental dependence of the radiation-chemical yields of ethylene glycol on formaldehyde concentration in γ-radiolysis of methanol–formaldehyde solutions at 373–473 K is shown. At a formaldehyde concentration of 1.4 mol dm–3 and T = 473 K, the radiation-chemical yield of ethylene glycol is 139 molecules per 100 eV. The effective activation energy of ethylene glycol formation is 25 ± 3 kJ mol–1. The quasi-steady-state treatment of the reaction network suggested here led to a rate equation accounting for the non-monotonic dependence of the ethylene glycol formation rate on the concentration of the free (unsolvated) form of dissolved formaldehyde. It is demonstrated that the peak in this dependence is due to the competition between methanol and CH2=O for reacting with adduct radical HOCH2CH2O•.

Keywords: Methanol, Formaldehyde, Formation, Ethylene Glycol, Radiation-Chemical Yield, Rate Equation.