Role of the transition metal complexes of 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (BINAP) in asymmetric catalysis

Metal complexes of 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (BINAP) are being used as a chiral catalysts in many organic reactions. This review highlights recent developments on synthesis of metal BINAPs and its application in various organic synthesis. The studies done on the application of metal BINAPs show a unique reactivity, which enables its use in entirely different sets of chemical transformation.     

Development of New Molecular Entities as Potent Antifungal Agents: Synthesis of Substituted 1,2,3-Triazoles

Russian Journal of General Chemistry - A series of novel 1,2,3-triazoles (8a–8m) were synthesized using click chemistry in excellent yields and were characterized by IR, NMR, MASS...     

Greener approach toward synthesis of biologically active s-Triazine (TCT) derivatives: A recent update

The greener methodology to synthesize s-triazine derivatives (also known as TCT) is described, including synthesis through microwave, ultrasound, and solvent-free conditions. This review mainly focuses on reactions of TCT (2,4,6-trichloro-1,3,5-triazine) with various substituents having amine and hydroxy functionalities to give corresponding triazine derivatives under a greener approach. The results of reactions indicate that, unlike classical methods, green methods result in better yields of the product, through a rapid reaction, under mild reaction conditions, and by easy workup procedures.     

Design,synthesis, and antibacterial studies of potent pyrazolinyltriazoles

Research on Chemical Intermediates - A library of pyrazolinyltriazole hybrids (3a–l, 4a–l) was synthesized via azide–alkyne dipolar (Huisgen) cycloaddition of azidoacetyl...     

Synthesis and antimicrobial activity of some novel benzofuran based 1,2,3-triazoles

In the present study, a series of novel {6-[(1H-1,2,3-triazol-4-yl)methoxy]-3-methylbenzofuran-2-yl}(phenyl)methanones (7a–7o) have been synthesized using click chemistry approach. The structures of all newly synthesized compounds were characterized by FT-IR, ¹H and ¹³C NMR, and MASS spectral data. Most of products demonstrated high antimicrobial activity.

     

Switchable ErSc2N rotor within a C80 fullerene cage: an electron paramagnetic resonance and photoluminescence excitation study

Motivated by the possibility of observing photoluminescence and electron paramagnetic resonance from the same species located within a fullerene molecule, we initiated an EPR study of Er3+ in ErSc2N@C80. Two orientations of the ErSc2N rotor within the C80 fullerene are observed in EPR, consistent with earlier studies using photoluminescence excitation (PLE) spectroscopy. For some crystal field orientations, electron spin relaxation is driven by an Orbach process via the first excited electronic state of the 4I(15/2) multiplet. We observe a change in the relative populations of the two ErSc2N configurations upon the application of 532 nm illumination, and are thus able to switch the majority cage symmetry. This photoisomerization, observable by both EPR and PLE, is metastable, lasting many hours at 20 K.     

Representation of orthofermion spin operators

The algebraic expressions for the total spin operators expressed in terms of orthofermion creation and annihilation operators are combined into a single equation. The terms in this expressions are rearranged to provide representations of local spin operators. This task is essential for modelling a system of orthofermions in the presence of a magnetic field. By factorizing the orthofermion annihilation (creation) operators into charge and spin dependent parts, it is shown that the latter part suffices to represent spin number, raising and lowering operators. Finally a connection is provided between the spin systems and Greenberg’s infinite statistics.     

A shape-optimization technique for the capillary surface problem

Summary The problem of the construction of an equilibrium surface taking the surface tension into account leads to Laplace-Young equation which is a nonlinear elliptic free-boundary problem. In contrast to Orr et al. where an iterative technique is used for direct solution of the equation for problems with simple geometry, we propose here an alternative approach based on shape optimization techniques. The shape of the domain of the liquid is varied to attain the optimality condition. Using optimal control theory to derive expressions for the gradient, a numerical scheme is proposed and simple model problems are solved to validate the scheme.     

Effect of cation doping on low-temperature specific heat of LaMnO3 manganite

We have investigated the thermodynamic properties of perovskite manganite LaMnO₃, the parent compound of colossal magnetoresistive manganites, with the Ca²⁺ doping at the A-site. As strong electron-phonon interactions are present in these compounds, the lattice part of the specific heat deserves proper attention. We have described the temperature dependence of the lattice contribution to the specific heat at constant volume (C_v(lattice)) of La_1−xCa_xMnO₃ (x=0.125, 0.175, 0.25, 0.35, 0.50, 0.67, 0.75) as a function of temperature (1 K–20 K) by means of a rigid ion model (RIM).The trends of specific heat variations with temperature are almost similar at all the composition. The Debye temperatures obtained from the lattice contributions are found to be in somewhat closer agreement with the experimental data. The specific heat values revealed by using RIM are in closer agreement with the available experimental data, particularly at low temperatures for some concentrations (x) of La_1−xCa_xMnO₃. The theoretical results at higher temperatures can be improved by including the effects of the charge ordering, van der Waals attraction and anharmonicity in the framework of RIM.