Synthesis and antimicrobial activity of a new class of methyleneamine‐linked bis‐heterocycles

A new class of methyleneamine‐linked bis‐heterocycles that exhibit antimicrobial activity was synthesized. Bromination of 1 followed by condensation with thiourea gave 3 . The reaction of 3 with propargyl bromide in dry toluene under inert atmosphere led to the formation of 4 . Its subsequent reaction with different aromatic azides 5 using CuSO₄.5H₂O‐sodiumascorbate system in a 2:1 mixture of water and tert‐butylalcohol yielded the title compounds 6a , 6b , 6c , 6d , 6e , 6f , 6g , 6h , 6i , 6j in good yields. The identities of these compounds were confirmed following elemental analysis, IR, ¹H, ¹³C NMR, and mass spectral studies. All the title compounds exhibited pronounced in vitro antibacterial and antifungal activities. J. Heterocyclic Chem., (2011).     

Coexistence of superconductivity and ferromagnetism in two dimensions

Ferromagnetism is usually considered to be incompatible with conventional superconductivity, as it destroys the singlet correlations responsible for the pairing interaction. Superconductivity and ferromagnetism are known to coexist in only a few bulk rare-earth materials. Here we report evidence for their coexistence in a two-dimensional system: the interface between two bulk insulators, LaAlO(3) (LAO) and SrTiO(3) (STO), a system that has been studied intensively recently. Magnetoresistance, Hall, and electric-field dependence measurements suggest that there are two distinct bands of charge carriers that contribute to the interface conductivity. The sensitivity of properties of the interface to an electric field makes this a fascinating system for the study of the interplay between superconductivity and magnetism.     

The black hole in astrophysics: the origin of the concept and its role

Theory of Elasticity. By L. D. Landau and E. M. Lifshitz. (Pergamon Press, 1970.) [Pp. vii + 165.] £3 0s. 0d. Scope: Treatise/textbook. Level: Specialist/postgraduate; undergraduate.

A Quantum Mechanics Primer. By Daniel T. Gillespie. (International Textbook Co., 1970.) [Pp. xiv + 137.] Scope: Treatise/textbook. Level: Undergraduate.

An Introduction to Quantum Physics. By Garrison Sposito. (John Wiley &; Sons Ltd., 1970.) [Pp. xviii + 425.] £6.15. Scope: treatise/Textbook. Level: Undergraduate.

An Introduction to Current Algebra. By D. H. LYTH. (Oxford University Press 1970.) [Pp. xi+ 66] 9Op. Scope: Treatise/textbook. Level: Specialist/postgraduate.

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Optics. By Miles V. Kleix. (John Wiley &; Sons Ltd., 1970.) [Pp. 647.] £8.00. Scope: Textbook. Level: Undergraduate.

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Crystals and X-rays. 13. By H. S. Lipson. (Wykeham Publications, 1970.) [Pp. xiv + 198.] £1.75. Scope: Library. Level: Undergraduate; School; General reader.

A Dictionary of Named Effects and Laws in Chemistry, Physics and Mathematics. By D. W. G. Ballentyne and D. R. Lovett. (Chapman &; Hall Ltd., 1970.) [Pp. viii + 335.] £3. Scope: Library(reference). Level: General reader.

Experimental Crystal Physics (Second Edition). By W. A. Wooster and A. Breton. (Clarendon Press, Oxford, 1970.) [Pp. ix+ 150.] £3. Scope: Textbook. Level: Undergraduate.

Physics. By Davidbryant.(The English Universities Press Ltd., 1971.) [Pp. viii+ 264.] 55p. Level: General reader.

Nuclear Reactions. By I. E. McCarthy. (Pergemon Press. 1970.) [Pp. viii+327.] £1.75. Scope: Textbook; library. Level: Specialist/postgraduate;undergraduate.

Studies in Statistical Mechanics. Vol. V. Edited by J. De Boer and G. E. Uhlenbeck. (North-Holland Publishing Co. 1971.) [Pp. xivf 239.] £5.00. Scope: Survey. Level: Specialist/postgraduate.

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Classical Thermodynamics. By Arnold Munster. (John Wiley &; Sons Ltd., 1970.) [Pp. xiv+ 387.] £6.00. Scope: Library. Level: Specialist/postgraduate.

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Electron Optics. By O. Klemperer and M. E. Barnett. (Cambridge University Press, 1971.) [Pp. ix+ 506.] £9.00. Scope: Textbook. Level: Undergraduate/postgraduate     

Synthesis of new 4-methyl-3-piperidones via an iron-catalyzed intramolecular tandem isomerization–aldolisation process

A new versatile synthesis of 3-piperidones is described, starting from amino acids. It uses, as a key step, an iron carbonyl-mediated intramolecular tandem isomerization–aldolisation reaction. These new heterocycles appear as useful scaffolds for the total synthesis of various types of bioactive molecules.     

Stereoselective synthesis of an advanced seco ester intermediate as a precursor toward the synthesis of amphidinolides T1, T3, and T4

An efficient, convergent, and stereoselective synthesis of a very advanced intermediate toward the total synthesis of amphidinolides T1, T3, and T4 utilising Evan’s aldol and alkylation reactions, oxy-Michael, cross metathesis, stereoselective Grignard addition, and Yamaguchi esterification reactions as key steps is described.     

One-photon photodetachment of I- in glycerol: spectra and yield of solvated electrons in the temperature range 329<or=T<or=536 K

Solvated electrons in glycerol were generated via a resonant one-photon photodetachment of the charge-transfer-to-solvent (CTTS) band of I- in glycerol (Gl) after irradiation with a 248 nm excimer laser. Optical absorption spectra of solvated electrons (esolv-) in Gl were recorded as a function of temperature (381相似文献   

A new stability indicating reverse phase high performance liquid chromatography method for the determination of enantiomeric purity of a DPP‐4 inhibitor drug linagliptin

A simple, sensitive, and stability indicating isocratic reverse phase high performance liquid chromatography method has been developed, optimized and validated for the separation and quantification of S‐enantiomer in linagliptin (R‐enantiomer) drug substance. Enantiomeric separation was achieved on a Cellulose tris(4‐chloro‐3‐methylphenylcarbamate) stationary phase. Mobile phase consists of aqueous diammonium hydrogen phosphate buffer and acetonitrile in the ratio of 35:65 v/v. Isocratic elution was performed at a flow rate of 1.0 mL/min, the column oven temperature was set at 40°C and detection was at 226 nm. The resolution between R and S enantiomers is found to be more than 4.0. The impact of mobile phase composition, pH of buffer and temperature on the resolution has been studied. The detector response is found to be linear over the concentration range of 0.17–1.7 μg/mL. LOD and LOQ levels of S‐enantiomer are found to be 0.057 and 0.172 μg/mL respectively. The recovery of S‐enantiomer is 99.8% w/w. The proposed method is validated for specificity, precision, linearity, accuracy and robustness.     

Strontium Tetraborate Glasses Doped with Transition Metal Ions: EPR and Optical Absorption Study

Electron paramagnetic resonance (EPR) and optical studies have been carried out on Cu(II)-, VO(II)- and Cr(III)-doped strontium tetraborate glasses to understand the distortion and substitution of these ions. The EPR results of Cu(II) glass indicate that g _∥ > g _⊥, typical for the tetragonally elongated octahedral site of the Cu(II) impurity. The evaluated covalency parameter 0.788 suggests a moderate covalency for the bonding. By correlating EPR and optical results, the in-plane π-bonding β₁ ² is evaluated as 0.715. In the vanadium-doped glasses, the distortion must be a tetragonally elongated octahedron, similar to Cu(II). However, the EPR studies show that g _⊥ > g _∥ indicating the tetragonally compressed octahedral site for the ion. The site symmetry is C _4V. Supported by the optical absorption, evaluated parameters propose a moderate covalency. The EPR and optical results for Cr(III) glass indicate the distorted octahedral site symmetry in the host lattice. These results further suggest that the bonding between Cr(III) and the ligands is covalent. Authors' address: Renduchintala V. S. S. N. Ravikumar, Department of Physics, Acharya Nagarjuna University, Nagarjuna Nagar 522510, India     

A holographic,radial and lateral shear interferometer

A new holographic shear interferometer is described in which both the radial and the lateral shear can be simultaneously introduced by using an off-axis zone plate.