Cyclo[2]benzimidazole: luminescence turn-on sensing of anions

Cyclo[2]benzimidazole is a new host for anions that turns on its luminescence up to 150 fold upon binding. Photoexcited cyclo[2]benzimidazole undergoes an efficient non-radiative deactivation through an excited-state intramolecular proton-transfer (ESIPT) mechanism. Upon binding an anion, the ESIPT pathway is blocked, resulting in an increase in the luminescence efficiency.     

Extending the applicability of the Gauss–Newton method under average Lipschitz–type conditions

We extend the applicability of the Gauss–Newton method for solving singular systems of equations under the notions of average Lipschitz–type conditions introduced recently in Li et al. (J Complex 26(3):268–295, 2010). Using our idea of recurrent functions, we provide a tighter local as well as semilocal convergence analysis for the Gauss–Newton method than in Li et al. (J Complex 26(3):268–295, 2010) who recently extended and improved earlier results (Hu et al. J Comput Appl Math 219:110–122, 2008; Li et al. Comput Math Appl 47:1057–1067, 2004; Wang Math Comput 68(255):169–186, 1999). We also note that our results are obtained under weaker or the same hypotheses as in Li et al. (J Complex 26(3):268–295, 2010). Applications to some special cases of Kantorovich–type conditions are also provided in this study.     

An effective force field for molecular dynamics simulations of dimethyl sulfone

A rigid five-site united atom model for dimethyl sulfone (DMSO₂) compatible with the GROMOS force field is parametrized and tested. The parameters were optimized with respect to experimental quantities such as liquid density, heat of vaporization, shear viscosity and excess free energy. Good agreement with pure component properties is achieved except for the static dielectric permittivity which is calculated too low. Together with the SPC model for water the new DMSO₂ model was used to study aqueous mixtures at low concentrations and compared to aqueous mixtures of DMSO. It is concluded that interaction parameters for sulfoxide oxygen are not directly transferable to sulfonyl oxygen.     

Recent advances in the organic synthesis at high pressure. Effect of pressure on the macrocyclization reaction

Abstract

α,ω-Tertiary diamines react under high pressure with α,ω-di-iodo compounds to give cyclic or bicyclic bis-quaternary salts in almost quantitative yields. The role of high-pressure-induced changes in conformation of linear intermediates and the viscosity factor are discussed.     

Investigation of neutron emission from relativistic heavy ion interactions by nuclear tracks

Fast neutrons produced in 44 and 22 GeV ¹²C+Cu interactions have been recorded and analysed with a CR-39 detector stack. The irradiation of the CR-39 stack to fast neutrons was carried out at the accelerator Synchrophasotron, Joint Institute for Nuclear Research, Dubna, Russia. Areal and volume densities of tracks induced by fast neutrons in the CR-39 at different positions and for different etching time have been measured. The neutron production ratio of 44 GeV to 22 GeV ¹²C+Cu interactions has been obtained, which is 2.17 ± 0.30 by areal track density, or 2. 12±0.33 by step etch technique, or 2.03±0.34 by volume track density measurement. These results confirm that the production rate at 44 GeV ¹²C+Cu interactions is more than theoretical estimation.     

Conduction studies on electrodeposited indium selenide thin films

Indium Selenide thin films were electrodeposited on Indium Tin Oxide (ITO) coated glass substrates from a mixture of Indium trichloride (InCl₃) and selenium dioxide (SeO₂) in aqueous solution by the potentiostatic electrodeposition technique. The InSe films showed that Mott’s variable-range hopping conductivity (VRH) is dominant under low field (∼2×10⁵ Vcm⁻¹) condition. At high field the Current-Voltage studies (in the temperature range 300 – 380 K) revealed that the conductivity of Indium selenide thin films is of Poole-Frenkel type. The plot drawn between Ln (I/V) and tV showed a straight line and also the experimental data and the theoretical data closely matches. Hence Poole-Frenkel mechanism is confirmed and discussed in detail. Paper presented at the 2nd International Conference on Ionic Devices, Anna University, Chennai, India, Nov. 28–30, 2003.     

How simple can a thermotropic mesogenic molecule be? Supramolecular layers through a network of hydrogen bonds

The supramolecular approach was applied to obtain a thermotropic liquid crystalline phase from the smallest possible molecules. Diaminobenzene derivatives are able to form smectic layers through a network of interconnected hydrogen bonded rings. The observed smectic A phase exhibits unusually small optical birefringence, comparable with that of lyotropic lamellar phases.     

Celtine,celtisine and breoganine,new phenolic cularine alkaloids from fumariaceae

Three new phenolic cularines have been isolated from Sarcocapnos and Corydalis species. Their structures have been elucidated on the basis of spectroscopic studies and chemical transformations.     

Prescribed Mean Curvature Hypersurfaces in Hn+1(-1) with Convex Planar Boundary, I

We study immersed prescribed mean curvature compact hypersurfaces with boundary in Hⁿ⁺¹(-1). When the boundary is a convex planar smooth manifold with all principal curvatures greater than 1, we solve a nonparametric Dirichlet problem and use this, together with a general flux formula, to prove a parametric uniqueness result, in the class of all immersed compact hypersurfaces with the same boundary. We specialize this result to a constant mean curvature, obtaining a characterization of totally umbilic hypersurface caps.