Some novel neighborhood degree sum-based versus degree-based topological indices in QSPR analysis of alkanes from n-butane to nonanes

The topological indices are reported to be very useful in various QSPR studies as these indices can be utilized as a tool to predict the physicochemical properties of a diverse set of chemical compounds. The objective of this communication is twofold. First, to introduce some neighborhood degree sum-based topological indices and perform a comparative QSPR analysis of the indices with their corresponding degree-based topological indices to analyze the usefulness of the new indices. Second, to investigate isomer discrimination ability of the newly defined indices on the basis of degeneracy test. Neighborhood degree sum-based topological indices not only consider the degree of each atom in the molecule but also the degrees of its neighboring atoms. Moreover, these indices are expected to provide information about how connected and dense the neighborhoods of atoms are within the molecule. In this study, we observe that the proposed neighborhood degree sum-based topological indices exhibit better correlation with some physicochemical properties of Octane Isomers and 66 alkanes as compared to their corresponding degree-based topological indices. Also, the supremacy in terms of sensitivity of the neighbourhood degree sum-based topological indices as compared to the classical degree-based ones is established.     

Generation of new classes of exactly solvable potential from the trigonometric Rosen-Morse potential

Exact analytic solutions of the Schr?dinger equation are obtained for classes of newly constructed potentials which are generated from the trigonometric Rosen-Morse potential as the input reference potential via extended transformation method. A set of quantized energy spectra of the bound states and the corresponding wave functions of the generated potentials are obtained. We also focus on to the Romanovski Polynomials which is a family of the real orthogonal polynomials and is required to present exact real analytic solutions of the generated potentials.     

Laboratory measurements of light scattering by tropical fresh water diatoms

Laser light scattering characteristics of tropical fresh water diatoms and their siliceous frustules have been measured as a function of scattering angle at 543, 594 and 632 nm wavelengths by using an indigenously designed and fabricated laboratory light scattering instrument in an attempt to carryout morphological characterization of the unique regular structures specific to these type of tropical fresh water diatoms. The instrument incorporates an array of 16 highly sensitive static Si detectors that measured scattered light signals from 10° to 170° in steps of 1°. A comparative analysis between the results obtained by using the three different incident wavelengths has shown that highest resolution is obtained at 543 nm incident wavelength.     

Luminescence studies of fresh water diatom frustules

Siliceous frustules were extracted from fresh water diatoms by treating with concentrated HCl. The diatom frustules consist of nano-porous silica structures that exhibit unique optoelectronic and photonic properties. Photoluminescence (PL) properties of diatom frustules at various excitation wavelengths were done. A visible PL band centered at 440 nm was observed when excited at 300 nm, 370 nm and 380 nm wavelengths. The observed PL activity of the diatom frustules has the potential for use in optoelectronic and photonic devices.     

Monitoring of pathogen carrying air-borne tea dust particles by light scattering

In order to investigate whether tea (Camellia sinensis (L.) Kuntze) dust particles could be a possible carrier of the pathogen contaminated Mycobacterium a biotechnical procedure was used, and to verify the possibility of monitoring this dust, a laser based light scattering setup was designed and fabricated. Experiments were carried out using the strain Mycobacterium smegmatis mc² 155 as a model organism to study the effect on tea dust particles. Light scattering investigations on both M. smegmatis contaminated and uncontaminated tea dust particle samples were carried out as a function of scattering angle at 543.5, 594.5 and 632.5 nm wavelengths. The results have shown that the behavior of tea dust samples both with and without Mycobacterium varies significantly for all the three different incident laser wavelengths.     

Acetanilide palladacycle: an efficient catalyst for room‐temperature Suzuki–Miyaura cross‐coupling reaction

The catalytic activity of three acetanilide palladacycles derived from easily accessible and commercially available acetanilide derivatives, viz. N‐phenylacetamide ( L1 ), N‐(4‐chlorophenyl)acetamide ( L2 ) and N‐(4‐methylphenyl)acetamide ( L3 ) has been examined in Pd‐catalyzed Suzuki–Miyaura reaction of arylboronic acid with aryl bromides at room temperature. The complex 1L3 exhibited efficient activity in the Suzuki–Miyaura reaction (up to 99% isolated yield) under mild reaction conditions. Copyright © 2014 John Wiley & Sons, Ltd.