The Interrelationship between Thermodynamics and Energetics: The True Sense of Equilibrium Thermodynamics
Pages 19-47
Evgeni B. Starikov

DOI: http://dx.doi.org/10.6000/1929-5030.2015.04.01.3

Published: 25 Feburary 2015

Abstract: The interrelationship between the conventional thermodynamics and energetics has been discussed in detail. A number of flavors has been considered in the field of energetics, with the conclusion that the actual difference among all of them is rather superficial. A need to reconsider the foundations of thermodynamics and statistical physics has been pointed out. Such a re-consideration ought to facilitate formulating thermodynamics at any level of matter organization: from the microscopic through nano- and mesoscopic to the macroscopic one.

Effects of Metal Ions on H₂ Generation during Photolysis of Suspended TiO₂ in Aqueous Systems
Pages 63-71
G.R. Dey

DOI: http://dx.doi.org/10.6000/1929-5030.2015.04.01.5

Published: 25 Feburary 2015

Abstract: Nowadays, photocatalysis is being applied as a promising technique for decontamination, purification, deodorization, etc. of polluted air and wastewaters. This technique attempts also to generate renewable and non-polluting fuels utilizing various carbon and hydrogen sources. In this context, studies on photo-catalytic generation of H₂ using 0.1% w/v TiO₂ photo catalyst as a suspension in water was carried out using 350 nm light. This was explored further in presence of various metal ions such as Ag⁺, Cu²⁺, Fe²⁺, Au³⁺ and V⁵⁺ at different ambient such as air and CO₂, in presence of a hole scavenger (2-propanol and formic acid). H₂ yields in CO₂-purged systems as analyzed in GC-TCD were reasonably higher, and increased further when metal ions were added into the systems. Based on H₂ yields, HCOOH was found to be a more supportive hole scavenger as compared to 2-propanol in metal ions containing systems. Besides the formation of low to high concentrations of various gaseous products, nanoparticles of gold, silver and copper were also observed as photolysis products. This indicated that the presence of both reduced metal ions and their in-situ generated nanoparticles at various stages either in the free/unbound and/or associated with TiO₂ photocatalyst in aqueous systems, together play a significant role in enhancing the H₂ yields.

Volumetric Properties of Cyclic Alanylalanine in Aqueous Solutions of MnCl₂, NiCl₂ and ZnCl₂ at Temperatures T = (293.15 to 313.15) K
Pages 48-62
V.R. Karanth and D. Krishna Bhat

DOI: http://dx.doi.org/10.6000/1929-5030.2015.04.01.4

Published: 25 Feburary 2015

Abstract: The partial molar volumes, isentropic compressibilities, partial molar isentropic compressions and transfer molar quantities of cyclic alanylalanine in water and in aqueous solutions of MnCl₂, NiCl₂ and ZnCl₂ were determined using the experimental density and speed of sound values. Refractive indices of all the solutions were recorded to calculate the molar refractions. The molecular interactions existing in the systems have been discussed based on the derived parameters. It has been found that M²⁺-O₂H bond distances of hydrated cations influence on the volumetric properties of cyclic alanylalanine. Further, the greater effect of hydrophobic hydration has been substantiated by the S_v values of least square fits of apparent molar volume against solute molality.

Pyrrolidinyl Group as Charge Donor for the Excited State Intramolecular Chargetransferin 3-(4-methoxyphenyl)-1-(4-(pyrrolidin-1-yl) phenyl) Prop-2-en-1-one
Pages 72-82
Nidhi Mishra, Kamal Kumar Chaudhary and Satish Kumar Awasthi

DOI: http://dx.doi.org/10.6000/1929-5030.2015.04.01.6

Published: 25 Feburary 2015

Abstract: The absorption and steady state emission properties of a chemically synthesizedchalcone, 3-(4-methoxyphenyl)-1-(4-(pyrrolidin-1-yl) phenyl) prop-2-en-1-one (MPPP) containingasymmetrical donor and acceptor groups has been investigated both experimentally andtheoretically. The ground state, MPPP has a significant intramolecular charge transfer (ICT) character and a great sensitivity to the hydrogen bond donating ability of the medium as reflected from the absorption spectra in pure non polar, polar and neutral solvents. On the other hand, its excited singlet state exhibits high ICT characters as manifested by the drastic solvatochromic effects. These results are consistent with the data. The absorption spectra of the compound MPPP undergoes minor changes with increasing polarity of the solvents and the fluorescence spectra experiences a distinct bathochromic shifts in the both position and fluorescence quantum yields, increases reaching a maximum before decrease with increasing the solvent effects. The quantum yields decrease with increase in the solvent polarity. The magnitude of change in the dipole moment was also calculated using Austin Model 1 (AM1). These results suggest that the evidence about the intramolecular charge transfer in the emitting singlet state of this compound. The solvent dependence of quantum yields of MPPP was interpreted on the basis of positive and negative solvatokinetic as well as hydrogen bonding effects. Intramolecular charge (ICT) transfer took place from pyrrolidine nitrogen to α, β unsaturated carbonyl in the ground state..