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731.
In this paper some new kinds of generalized Logarithmic and Harmonic Convex functions have been introduced and their relationships
with known concepts have been discussed. 相似文献
732.
A simple synthesis of acenaphthoquinolines by thermal cyclization of anils is described. 相似文献
733.
In this paper, weak distinguished subcategory and distinguished subcategory of modules are introduced. Left(right) local unital rings are particularly considered. Also, representable equivalent functors between categories. By using the replacement techniques of modules, a general theory of Morita equivalence for infinite matrix rings is established. This theory not only extends the classical Morita theory of equivalence from finite matrix rings to infinite matrix rings and also contains some new results which are useful in studying the algebraic structures for infinite matrix rings. Some results of classical Morita theory are included as its special cases. 相似文献
734.
735.
Arijit Hazra Anil Kumar Barik Sachindranath Pal Samik Gupta Somnath Roy Ray J. Butcher Shie-Ming Peng G.H. Lee Susanta Kumar Kar 《Polyhedron》2007
Three mononuclear cis-dioxovanadium(V) complexes of tridentate thiosemicarbazones derived from 5-methyl-3-formylpyrazole (MPA) and N(4)-methyl/ethyl/dimethyl thiosemicarbazide have been synthesized and characterized. Single crystal X-ray analyses were performed with [VO2L1] (1), [VO2L2] (2) and [VO2L3] (3), where L1, L2 and L3 denote the [1 + 1] thiosemicarbazone mono-anions derived from MPA and N(4)-substituted methyl/ethyl/dimethyl thiosemicarbazide respectively. In all the complexes the vanadium atom is in a distorted square pyramidal geometry with a N2SO2 chromophore. The interesting finding in the work is that in complexes 1 and 2, the thioimine nitrogen unusually participates in coordination whereas in 3 it is the azomethine nitrogen (quite usual) which is involved in the coordination process. 相似文献
736.
Prasenjit Kar Moorthy SureshD. Krishna Kumar D. Amilan JoseBishwajit Ganguly Amitava Das 《Polyhedron》2007
Two new anthraquinone based receptors have been synthesized. A colour change for both these receptors could be detected when group IIA metal ions were added in DMF solution at room temperature. No such colour change was noticed for group IA metal ions. Association constants for these receptors towards Mg2+, Ca2+, Sr2+ and Ba2+ were evaluated by systematic spectrophotomeric titrations and they follow the order KMg(II) ? KCa(II) > KSr(II) ? KBa(II). The association constants for L1 were found to be higher than those for L2 toward group IIA metal ions. Ab initio quantum chemical calculations have been performed to rationalize these observed results. X-ray structural analysis shows a helical structure for one of the receptor molecules. 相似文献
737.
L. I. Yakovenkova L. E. Kar’kina O. A. Elkina 《Bulletin of the Russian Academy of Sciences: Physics》2011,75(5):650-652
An electron microscopic analysis of the dislocation structure of two-phase α2/β Ti-21.4 at % Al-5.6 at % Nb alloy deformed at ambient temperature was performed. It was established that after deformation,
the microstructure of the α2 phase consists of mobile a-superdislocations in the basal and prism planes and of 2c + a-superdislocations in the pyramidal planes. Some dislocations with the Burgers vector [0001] in the prism planes were also
observed. Deformation transfer from the α2 to the β phase occurs only due to a-super-dislocations with a Burgers vector corresponding to the Burgers orientation relations between these phases. The reasons
for the increase in plasticity in two-phase Ti3Al with Nb alloys are discussed. 相似文献
738.
Mandal TN Roy S Konar S Jana A Ray S Das K Saha R El Fallah MS Butcher RJ Chatterjee S Kar SK 《Dalton transactions (Cambridge, England : 2003)》2011,40(44):11866-11875
The ditopic ligand PyPzOAP (N-[(Z)-amino(pyridin-2-yl)methylidene]-5-methyl-1-(pyridin-2-yl)-1H-pyrazole-3-carbohydrazonic acid) and the polytopic ligand 2-PzCAP (N'(3),N'(5)-bis[(1E)-1-(pyridin-2-yl)ethylidene]-1H-pyrazole-3,5-dicarbohydrazide) were synthesized in situ by condensation of methyl imino picolinate with 5-methyl-1-(2-pyridyl) pyrazole-3-carbohydrazide and 2-acetyl pyridine with pyrazole-3,5-dicarbohydrazide respectively. The ligands PyPzOAP and PzOAP (reported earlier, Dalton Trans., 2007, 1229) self-assemble to form homoleptic [2 × 2] tetranuclear M(4) (M = Cu(II) and Ni(II)) square grids structures [Cu(4)(PyPzOAP)(4)](NO(3))(4) (1), [Cu(4)(PzOAP)(4)](ClO(4))(4) (2) and [Ni(4)(PyPzOAP)(4)](NO(3))(4)·8H(2)O·2CH(3)CN (3). While the ligand 2-PzCAP forms a dicopper(II) complex [Cu(2)(2-PzCAP)(OH)(NO(3))(H(2)O)](NO(3))·2H(2)O (4). The complex 1 is a perfect square grid (a = 4.201 ?), whereas, 2 and 3 are almost square grids. All these compounds have been characterized by X-ray structural analyses and variable temperature magnetic susceptibility measurements. EPR studies have also been carried out for complexes 1, 2 and 4. In the Cu(4) grid (1), all the Cu(II) centers are in a distorted octahedral environment with N(4)O(2) chromophore, while, in complex 2, all four Cu(II) centers have a square pyramidal environment with N(3)O(2) chromophore. In complex 3, all four Ni(II) centers have distorted octahedral geometry with N(4)O(2) chromophore. In compound 4, the Cu(II) centers are in square pyramidal environment with N(3)O(2) chromophore. The magnetic properties of compounds 1 and 2 show the presence of intramolecular ferromagnetic exchange interaction (J = 5.88 cm(-1) for 1 and 4.78 cm(-1) for 2). The complex 3 shows weak intramolecular antiferromagnetic interaction (J = -4.02 cm(-1)). While, complex 4, shows strong antiferromagnetic behavior (J = -443 cm(-1)). 相似文献
739.
Saugata KonarAtanu Jana Kinsuk DasSangita Ray Sudipta ChatterjeeJames A. Golen Arnold L. RheingoldSusanta Kumar Kar 《Polyhedron》2011,30(17):2801-2808
Varying coordination modes of the Schiff base ligand H2L [5-methyl-1-H-pyrazole-3-carboxylic acid (1-pyridin-2-yl-ethylidene)-hydrazide] towards different metal centers are reported with the syntheses and characterization of four mononuclear Mn(II), Co(II), Cd(II) and Zn(II) complexes, [Mn(H2L)(H2O)2](ClO4)2(MeOH) (1), [Co(H2L)(NCS)2] (2), [Cd(H2L)(H2O)2](ClO4)2 (3) and [Zn(H2L)(H2O)2](ClO4)2 (4), and a binuclear Cu(II) complex, [Cu2(L)2](ClO4)2 (5). In the complexes 1-4 the neutral ligand serves as a 3N,2O donor where the pyridine ring N, two azomethine N and two carbohydrazine oxygen atoms are coordinatively active, leaving the pyrazole-N atoms inactive. In the case of complex 5, each ligand molecule behaves as a 4N,O donor utilizing the pyridine N, one azomethine N, the nitrogen atom proximal to the azomethine of the remaining pendant arm and one pyrazole-N atom to one metal center and the carbohydrazide oxygen atom to the second metal center. The complexes 1-4 are pentagonal bipyramidal in geometry. In each case, the ligand molecule spans the equatorial plane while the apical positions are occupied by water molecules in 1, 3 and 4 and two N bonded thiocyanate ions in 2. In complex 5, the two Cu(II) centers have almost square pyramidal geometry (τ = 0.05 for Cu1 and 0.013 for Cu2). Four N atoms from a ligand molecule form the basal plane and the carbohydrazide oxygen atom of a second ligand molecule sits in the apex of the square pyramid. All the complexes have been X-ray crystallographically characterized. The Zn(II) and Cd(II) complexes show considerable fluorescence emission while the remaining complexes and the ligand molecule are fluorescent silent. 相似文献
740.
Kar M Pauline M Sharma K Kumaraswamy G Gupta SS 《Langmuir : the ACS journal of surfaces and colloids》2011,27(19):12124-12133
Polypeptide-coated silica nanoparticles represent an interesting class of organic-inorganic hybrids since the ordered secondary structure of the polypeptide grafts imparts functional properties to these nanoparticles. The synthesis of a poly-l-glutamic acid (PLGA) silica nanoparticle hybrid by employing N-carboxyanhydride (NCA) polymerization to synthesize the polypeptide chains and Cu catalyzed azide alkyne cycloaddition reaction to graft these chains onto the silica surface is reported. This methodology enables the synthesis of well-defined polypeptide chains that are attached onto the silica surface at high surface densities. The PLGA-silica conjugate particles are well dispersed in water, and have been thoroughly characterized using multinuclear ((13)C, (29)Si) solid state NMR, thermogravimetric analysis, Fourier transform infrared, dynamic light scattering, and transmission electron microscopy. The pH-dependent reversible aggregation of the PLGA-silica particles, driven by the change in PLGA structure, has also been studied. Preliminary results on the use of aqueous dispersions of silica-PLGA for the preparation of three-dimensional macroporous structures with oriented pores by ice templating methodology are also demonstrated. These macroporous materials, comprising a biocompatible polymer shell covalently attached to rigid inorganic cores, adopts an interesting lamellar structure with fishbone-type architecture. 相似文献