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101.
Aguilar MI Purcell AW Devi R Lew R Rossjohn J Smith AI Perlmutter P 《Organic & biomolecular chemistry》2007,5(18):2884-2890
Hybrid peptides consisting of alpha-amino acids with judiciously placed beta-amino acids show great promise as peptidomimetics in an increasing range of therapeutic applications. This reflects a combination of increased stability, high specificity and relative ease of synthesis. 相似文献
102.
Kumari S Prabhakar S Vairamani M Devi CL Chaitanya GK Bhanuprakash K 《Journal of the American Society for Mass Spectrometry》2007,18(8):1516-1524
L-Tyrosine and iodinated L-tyrosines, i.e., 3-iodo-L-tyrosine and 3,5-diiodo-L-tyrosine, are successfully used as chiral references for the chiral discrimination of aliphatic, acidic, and aromatic amino acids. Chiral discrimination is achieved by investigating the collision-induced dissociation spectra of the trimeric complex [Cu(II)(ref)(2)(A) - H](+) ion generated by electro spraying the mixture of D- or L-analyte amino acid (A), chiral reference ligand (ref) and M(II)Cl(2) (M = Ni and Cu). The relative abundances of fragment ions resulted by the competitive loss of reference and analyte amino acids are considered for measuring the degree of chiral discrimination by applying the kinetic method. The chiral discrimination ability increases as the number of iodine atom increases on the aromatic ring of the reference and the discrimination is better with Cu when compared with Ni. A large chiral discrimination is obtained for aliphatic and aromatic amino acids using iodinated L-tyrosine as the reference. Computational studies on the different stabilities of the diastereomeric complexes also support the observed differences measured by the kinetic method. The suitability of the method in the measurement of enantiomeric excess over the range of 2% to 100% ee with relative error 0.28% to 1.6% is also demonstrated. 相似文献
103.
Lakshmi Devi AS Srinivasa Rao Y Satish M Jyothi G Babu Rao K Omdutt T 《Magnetic resonance in chemistry : MRC》2007,45(8):688-691
Thermal degradation of amlodipine base causes intramolecular reactions affording three cyclic products, referred to as AMLDEG-I, AMLDEG-II, and AMLDEG-III, respectively. AMLDEG-I is a cyclized product formed by intramolecular elimination of ammonia from amlodipine. AMLDEG-II is a positional isomer of AMLDEG-I. AMLDEG-III is also intramolecular cyclisation product. The three degradation products were isolated by column chromatography and characterized by FT-IR and 1H and 13C NMR spectroscopy data. The AMLDEG-III was crystallized and its structure was solved by single crystal X-ray diffraction (SXRD). 相似文献
104.
Bhupal S. Karki Lalita Devi Ayushi Pokhriyal Ruchir Kant Namrata Rastogi 《化学:亚洲杂志》2019,14(24):4793-4797
A metal‐free, regioselective synthesis of trisubstituted pyrroles has been developed through a formal [3+2] cycloaddition reaction between 2H‐azirines and nitroalkenes under visible light/photoredox‐catalyzed conditions. The reaction proceeds through 2H‐azaallenyl radical addition on β‐nitrostyrenes in a Michael fashion followed by a base‐mediated denitration reaction. The directive group influence of the nitro group controls the regiochemistry of the reaction. 相似文献
105.
Andrian P. Milanov Raghunandan Bhakta Manuela Winter Klaus Merz Anjana Devi 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(7):m370-m372
The title compound, [Hf(C11H23N2)2Cl2], is a monomeric hafnium(IV) complex containing two bidentate amidinate ligands and two cis Cl atoms. The crystals are triclinic (space group ) and there is one independent six‐coordinate monomer with a highly distorted octahedral geometry in the asymmetric unit. The reported structure is the first hafnium–amidinate complex to be characterized successfully by single‐crystal X‐ray diffraction. 相似文献
106.
107.
The degradation efficiency of Th-doped TiO2 / TiO2 photocatalysts were investigated under UV and solar light illumination. The model compound chosen for the study was Oryzalin
(OZ). Doping of inner transition metal ion Th was intended to modify the electronic properties of TiO2. The Th-doped TiO2 were synthesized by incorporating 0.02, 0.04, 0.06, and 0.1 atom percentage of Th into the TiO2 lattice by solid-state reaction. The stochiometry of the prepared samples is Ti1−xThxO2, where ‘x’ is the percentage of Th. The samples were characterized by UV-Visible absorption, UV-Visible -Diffused reflectance
spectra, Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Analysis (EDX) and X-ray Diffraction (XRD). The pore
size and surface area of these samples were studied by Brunauer, Emmett and Teller (BET) adsorption method. It was found that
metal ion doping at various percentage compositions enables a large shift in the absorption band of the TiO2 towards visible light region. This is due to the formation of various mid band gaps at 2.84 eV, 2.804 eV, 2.66 eV, and 2.55
eV. The extent of degradation of the pesticide was followed by UV-Visible spectroscopy and GC-MS methods. Based on the spectral
analysis, the probable degradation reaction mechanism for OZ is proposed. These results indicate that Th-doped TiO2 with the modified electronic properties is a good catalyst under solar light irradiation. But these particles show marginal
variation in rates under UV-illumination. All the photodegradation reactions follow the first order kinetics.
相似文献
108.
Synthesis,growth, morphology and characterization of ferroelectric glycine phosphite single crystals
Glycine phosphite (NH3CH2COO.H3PO3), a potential ferroelectric material, was grown as single crystals from aqueous solutions by slow evaporation and slow cooling methods. Laboratory synthesized title compound was purified by recrystallization method and confirmed by Fourier transform infrared and Laser Raman studies. Temperature dependent solubility in double distilled water in the range between 288 and 328 K was determined by gravimetric method. Morphological importance of various growth faces were studied by optical goniometry. Powder x‐ray diffraction study performed on the grown crystals confirms the crystal system and lattice parameters of the unit cell. Optical transparency of the grown crystals in the ultraviolet–visible ‐near infrared region was studied by spectroscopic method. Thermal stability of the grown crystals in the temperature region above ambient until melting was studied using differential scanning calorimetry. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
109.
A. V. Aparna Ch. Sarala Devi A. Padmaja B. Sireesha P. Raghavaiah 《Journal of chemical crystallography》2011,41(1):53-58
Abstract
Thiosemicarbazides and their derivatives are well known for their use in biological activity and many applications in pharmaceutical and industrial fields. The cyclization of 1-benzoyl-4-(2-nitrophenyl)-3-thiosemicarbazide (BNPTSC) in dimethylformamide (DMF) medium furnished N-(2-nitrophenyl)-5-phenyl-1,3,4-oxadiazole-2-amine (NPPOA). The chemical structure of the above substituted 1,3,4-oxadiazole has been assigned by IR, mass and X-ray diffraction studies. The XRD studies reveal the presence of four types of hydrogen bonds (N–H···O, N–H···N, C–H···O, C–H···N) in the crystal packing. The crystal system was found to be orthorhombic with a space group Pca2(1) and the unit cell dimensions are: a = 26.873(3) ?, b = 6.0827(7) ?, c = 7.8502(10) ?, α = 90°, β = 90°, γ = 90° and Z = 4. 相似文献110.
Shashikanth Ponnala Devi Prasad Sahu Rishi Kumar Prakas R. Maulik 《Journal of heterocyclic chemistry》2006,43(6):1635-1640