Synthesis of Imidazolato and 2-Methyl-Imidazolato Derivatives of Tellurium(IV)

INTRODUCTION

The chemistry of S-N compounds has been well established^[1] in the past few years and the stability was accounted in terms of extensive π bonding^[2,3]. The diversity of these compounds tempted chemsits to explore analogous Se-N and Te-N compounds. However, the poor or even absence of π bonding with heavier Se and Te posed problem to synthesize such compounds in the past. The chemistry of Se-N and Te-N compounds has been developed extensively by introducing new synthetic precursors^[4] in the last decade or so. We have observed that N-trimethyl silylimidazole and 2-methyl silylimidazole are potential reagents for peperation of monomeric transition metal imidazolates and Tin(IV) imidazolate^[5,6]. We, therefore, thought worthwhile to synthesize amido derivatives of Te(IV) incorporating these π delocalised heterocycles which acts as potential 4e (both σ and π) donors.     

Synergistic extraction of cobalt(II) with oxine/decanoic acid solution mixtures in benzene and chloroform

Synergistic extraction of Co(II) with 8-hydroxyquinoline (Hq)/decanoic acid [(HR)₂] solution mixtures in benzene and chloroform was carried out at 25°C. The aqueous ionic strength and the total concentration of cobalt(II) were 0.1 (NaCl) and 1·10^–5–1·10^–3M, respectively. The synergistic effect is interpreted by the formation of the mixed ligand ion-pair complexes: [(Coq(Hq)₂(HR))⁺, R^–] and [(Coq(Hq)₂(HR)₃)⁺, R^–] in benzene and chloroform, respectively.     

Method of poles for multilayer thin-film waveguides

The mode indices of a waveguide are found as the poles of the reflectance in the superstrate or the substrate. Complicated boundary condition problems are avoided by using the recursion relations for the reflectance. The method is especially suited for computer waveguide design.     

Metal-ion directed synthesis of binuclear octaazamacrocyclic complexes of manganese(II), cobalt(II), nickel(II), copper(II) and zinc(II) and their physico-chemical studies

A novel series of 16-membered binuclear complexes of octaazatetraimine ligand, [M = Mn^II, Co^II, Ni^II, Cu^II and Zn^II; X = Cl or NO₃] have been synthesized by metal template condensation reactions of o-phenylenediamine with N,N′-diacetylhydrazine in 1:1:1 molar ratio in methanol. The proposed stoichiometry and the bonding of the macrocyclic moiety to metal ions along with the overall stereochemistry have been derived from the results of elemental analyses, magnetic susceptibility, conductivity data and the spectral data revealed from FT-IR, , ESI mass, UV–visible studies. An octahedral geometry has been envisaged for Mn^II, Co^II, and Ni^II complexes while a slight distortion in octahedral geometry has been noticed for Cu^II complexes. The low conductivity data of all the complexes suggest their non-ionic nature.     

Copper vanadate nanowires-based MIS capacitors: synthesis,characterization, and their electrical charge storage applications

Dielectric properties of porous glass nanocomposites with TGS crystals embedded into six porous matrices with average pore size from 5 to 312 nm were investigated in the temperature range from 280 to 380 K at selected frequencies. The results are discussed based on the effect of the particle size on the phase transition temperature of TGS nanocomposites. Temperature–size phase diagram of TGS composites was derived. Non-monotonic character of the temperature-driven phase transition (T _p) with the decreasing particle size was determined. The nature of the T _p variation can be ascribed to the size-effect theoretically predicted by Zhong et al. (Phys Rev B 50:698–703, 1994).     

Synthesis, spectroscopic and electrochemical studies of N,N-bis[(E)-2-thienylmethylidene]-1,8-naphthalenediamine and its Cu(II) complex: DNA cleavage and generation of superoxide anion

A novel tetradentate Cu(II) complex of the type, [CuL](NO(3))(2) was synthesized by the interaction of Schiff base ligand, N,N-bis[(E)-2-thienylmethylidene]-1,8-naphthalenediamine, L obtained by the condensation of thiophene-2-carboxaldehyde and 1,8-diaminonaphthalene. The formation of Schiff base ligand, L and its Cu(II) complex was confirmed on the basis of results of elemental analyses, mass, FT-IR, (1)H and (13)C{(1)H} NMR spectral studies. UV-Vis, EPR and magnetic susceptibility data support a square planar environment around Cu(II) ion. However, molar conductance values confirmed 1:2 electrolytic nature for the Cu(II) complex. The electrochemical studies of Cu(II) complex was carried out by using cyclic voltammetry which revealed the complex to exhibit quasi reversible process. The biological activity of Cu(II) complex such as ability to bind DNA and DNA cleavage were studied where the Cu(II) complex was shown to cause considerable DNA cleavage and also generated reactive oxygen species such as superoxide anion. Since it is known that various anticancer drugs act through induction of oxidative stress that is mediated by reactive oxygen species, our results suggest a putative role of Cu(II) complex similar to various anticancer drugs.     

Assessment of effective radium content and radon exhalation rates in soil samples

Effective radium content and radon exhalation rates in soil samples have been measured by ??Sealed Can Technique?? using LR-115 type II plastic track detectors. The soil samples were collected from Farrukhabad city of Utter Pradesh, India. The values of effective radium content were found to vary from 5.39 to 34.56?Bq?kg^?1 with an average value of 16.58?Bq?kg^?1 and a standard deviation of 7.16. The mass and surface exhalation rate has been found to vary from 0.41?×?10^?6 to 2.64?×?10^?6?Bq?kg^?1?d^?1 and 1.41?×?10^?6 to 9.10?×?10^?6?Bq?m^?2?d^?1, respectively. All the values of radium content in soil samples of study area were found to be quite lower than the permissible value of 370?Bq?kg^?1 recommended by Organization for Economic Cooperation and Development.     

Syntheses,Physico‐Chemical Studies and Antioxidant Activities of Transition Metal Complexes with a Perimidine Ligand

A series of mononuclear complexes of the type, [MLCl₂] [M = Co^II, Ni^II, Cu^II, and Zn^II] with a pyrimidene‐type ligand, which was synthesized by the reaction of 2‐furaldehyde and 1, 8‐diaminonaphthalene, was obtained. The ligand and its complexes were characterized by elemental analysis, IR, NMR, EPR, and UV/Vis spectroscopy, ESI‐mass spectrometry, magnetic susceptibility, molar conductivity, and thermogravimetric analyses. On the basis of UV/Vis spectroscopic and magnetic susceptibility data, an octahedral arrangement was assigned around all metal ions. The low molar conductivity data for all the complexes show their non‐electrolytic nature. The thermal behavior of the complexes was studied by TGA analyses. The electrochemical study carried out on the Cu^II complex exhibits a quasi reversible redox process. The ligand and its complexes showed potential antioxidant and antimicrobial activities.     

Novel Pd(ii)-salen complexes showing high in vitro anti-proliferative effects against human hepatoma cancer by modulating specific regulatory genes

We have reported the synthesis of a novel salen ligand and its mononuclear Pd-salen complexes derived from 2-{[2-hydroxy-3-{[(E)-(2-hydroxyphenyl)methylidene]amino}propyl)imino]methyl}phenol. The newly synthesized and isolated Pd(ii) complexes have been identified and fully characterized by various physico-chemical studies viz., elemental analyses, IR, UV-Vis, (1)H, (13)C NMR spectroscopy, electron spray ionization mass spectrometry (ESI-MS) and TGA/DTA studies. The molecular structure of the salen ligand has been ascertained by single-crystal XRD and it is coordinated to Pd(ii) ion through two nitrogen and two oxygen atoms. The UV-Vis data clearly suggest a square-planar environment around both the Pd(ii) ions. The DNA binding studies of the synthesized compounds has been investigated by electron spectroscopy and fluorescence measurements. The results suggest that Pd(ii) complexes bind to DNA strongly as compared to the free ligand. The free salen ligand and its Pd(ii) complexes have also been tested against human hepatoma cancer cell line (Huh7) and results manifested exceptional anti-proliferative effects of the Pd(ii) complexes. The anti-proliferative activity of Pd(ii) complexes has been modulated by specific regulatory genes.     

Relativistic quantum particle in a time-dependent homogeneous field

A model of the relativistic quantum particle under the action of a time-dependent force is considered. This exactly solvable model is realized in the one-dimensional relativistic configurational x-space and is described by the finite-difference equation. The momentum p-space is one-dimensional Lobachevsky space. We have explicitly constructed the wave functions and propagators for this model in both x- and p-representations. We have also found a solution of a definite class of partial differential and finite-difference equations, which can be interpreted as the operator identities.