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431.
432.
Generalized trio coherent states are made by superposing a number of trio coherent states. They possess inherent nonclassical properties such as sub-Poissonian distribution and violation of Cauchy-Schwarz inequalities. Their phase distribution in the framework of the Pegg and Barnett theory is discussed. We study the interaction of the radiation field prepared in a generalized trio coherent state with an atom in a superposition coherent state in the rotating wave approximation. We investigate the time dependence of the sub-Poissonian distribution and the violation of Cauchy-Schwarz inequalities for such a system. General conclusions reached are illustrated by numerical results.  相似文献   
433.
Summary. 5-Amino-3-(3-methyl-5-oxo-1-phenyl-2-pyrazolin-4-yl)-7-phenyl-7H-thiazolo[3,2-a]pyrimidine-6-carbonitrile was synthesized via the reaction of 4-(2-aminothiazol-4-yl)-3-methyl-1-phenyl-2-pyrazolin-5-one with benzylidene malononitrile and was then transformed to related fused heterocyclic systems. The antifungal and antibacterial studies revealed in some cases excellent biocidal properties.  相似文献   
434.
A new flavonol triglycoside, isorhamnetin 3-O-beta-D-xylopyranosyl-(1"-->3)-alpha-L-rhamnopyranosyl-(1'-->6")-beta-D-galactopyranoside, has been isolated from the leaves of Hammada scoparia together with two known compounds, isorhamnetin 3-O-beta-D-apiofuranosyl-(1'-->2")[alpha-L-rhamnopyranosyl-(1"-->6")]-beta-D-galactopyranoside and isorhamnetin 3-O-alpha-L-rhamnopyranosyl-(1'-->2")[alpha-L-rhamnopyranosyl-(1"-->6")]-beta-D-galactopyranoside. The structures were determined by spectroscopic methods.  相似文献   
435.

Qternmet XR® (FDA approval, May 2019) is a multitarget anti-diabetic drug combination composed of metformin (MET), saxagliptin (SAX) and dapagliflozin (DAP). To our present knowledge, no analytical reports were found in the scientific databases for the simultaneous quantification of MET, SAX and DAP in their ternary combined tablets, moreover, no articles have attempted the simultaneous estimation of the cited drugs in any matrix using high-performance liquid chromatography with diode-array detection (HPLC–DAD) or high-performance thin-layer chromatography (HPTLC) technique. The current work represents a comparative study on two developed and validated chromatographic methods for the simultaneous determination of the ternary mixture (MET, SAX and DAP) in pure form and in combined tablet dosage form. The first method is reversed-phase HPLC using Agilent C18 column (4.6 × 250 mm, 5 μm p.s.) with a mobile phase consisting of acetonitrile and acidic aqueous phase pH 3 with a photodiode array detection at 230 nm. The second method is HPTLC in which drug solutions were applied to Merck HPTLC silica gel plates developed with a mixture of chloroform:methanol:water:acetic acid (7.4:2.6:0.5:0.01, v/v) and scanned at 224 nm. Both methods were fully validated following the ICH guidelines in terms of linearity, accuracy, precision, selectivity and robustness.

Representative HPLC (a) and HPTLC (b) chromatograms for a ternary mixture of metformin (MET), saxagliptin (SAX) and dapagliflozin (DAP)

  相似文献   
436.
Summary An indirect iodometric method has been developed for the determination of AgCl, AgBr, AgI, PbCl2, PbBr2, PbI2, PbSO4 and HgI2. The method does not require a prior dissolution of the sample. It is based on the exchange reaction between the insoluble salt and hydrogen sulphide, which yields a strong acid corresponding to the anion of the salt and in amount equivalent to the cation. The liberated acid is determined iodometrically. The method is simple, rapid and accurate.
Zusammenfassung Eine indirekte jodometrische Methode zur Bestimmung von AgCl, AgBr, AgJ, PbCl2, PbBr2, PbJ2, PbSO4 und HgJ2 wurde ausgearbeitet. Die Probe muß dazu nicht gelöst werden. Die Bestimmung beruht auf der Austauschreaktion zwischen dem unlöslichen Salz und Schwefelwasserstoff, die zur Freisetzung der dem Anion entsprechenden starken Säure in äquivalenter Menge führt. Diese wird jodometrisch titriert.


In memoriam Professor Cecil L. Wilson.  相似文献   
437.
Fluxional poly(pyrazolyl)borate complexes of copper and silver, including the carbonyl Cu(CO)B(pz)4, contain coordinated and free pyrazolyl groups, which interchange rapidly on the NMR time scale at room temperature; low temperature limiting spectra can be obtained for some copper complexes at ?100°.  相似文献   
438.
Complex equilibria of DCPHD with proton and Ni2+, Sm3+, and Yb3+ ions has been measured in various mixed aqueous solvents, viz: isopropanol-water, acetone-water, ethanol-water, and methanol-water. Based on potentiometric equilibrium measurements of hydrogen ion concentration at 30°C, ionic strenght 0.10 M (KNO3) and in the above various mixed aqueous solvents, the values of the protonation constants of DCPHD and the stability constants of DCPHD with Ni2+, Sm3+, and Yb3+ have been evaluated. The variation of protonation and stability constants with the inverse of dielectric constant or mole fraction of the solvent was studied. Application of Fuoss expression and consideration of electrosatic and non-electrostatic effects are made to explain the values of the constants.  相似文献   
439.
A tetranuclear mixed ligand copper(II) complex of a pyrazole containing Schiff base and a hydroxyhexahydropyrimidylpyrazole and copper(II) and nickel(II) complexes of the Schiff base having N-donor atoms have been investigated. A 2 equiv amount of 5-methyl-3-formylpyrazole (MPA) and 2 equiv of 1,3-diamino-2-propanol (1,3-DAP) on reaction with 1 equiv of copper(II) nitrate produce an unusual tetranuclear mixed ligand complex [Cu4(L1)2(L2)2(NO3)2] (1), where H2L1 = 1,3-bis(5-methyl-3-formylpyrazolylmethinimino)propane-2-ol and HL2 = 5-methyl-3-(5-hydroxyhexahydro-2-pyrimidyl)pyrazole. In contrast, a similar reaction with nickel(II) nitrate leads to the formation of a hygroscopic intractable material. On the other hand, the reaction involving 2 equiv of MPA and 1 equiv each of 1,3-DAP and various copper(II) salts gives rise to two types of products, viz. [Cu(T3-porphyrinogen)(H2O)]X2 (X = ClO4, NO3, BF4 (2)) (T3-porphyrinogen = 1,6,11,16-tetraza-5,10,15,20-tetrahydroxy-2,7,12,17-tetramethylporphyrinogen) and [Cu(H2L1)X]X x H2O (X = Cl (3), Br (4)). The same reaction carried out with nickel(II) salts also produces two types of compounds [Ni(H2L1)(H2O)2]X2 [X = ClO4 (5), NO3 (6), BF4 (7)] and [Ni(H2L1)X2] x H2O [X = Cl (8), Br (9)]. Among the above species 1, 3, and 5 are crystallographically characterized. In 1, all four copper atoms are in distorted square pyramidal geometry with N4O chromophore around two terminal copper atoms and N5 chromophore around two inner copper atoms. In 3, the copper atom is also in distorted square pyramidal geometry with N4Cl chromophore. The nickel atom in 5 is in a distorted octahedral geometry with N4O2 chromophore, where the metal atom is slightly pulled toward one of the axial coordinated water molecules. Variable-temperature (300 to 2 K) magnetic susceptibility measurements have been carried out for complex 1. The separations between the metal centers, viz., Cu(1)...Cu(2), Cu(2)...Cu(2)A, and Cu(2)A...Cu(1)A are 3.858, 3.89, and 3.858 A, respectively. The overall magnetic behavior is consistent with strong antiferromagnetic interactions between the spin centers. The exchange coupling constants between Cu(1)...Cu(2) and Cu(2)...Cu(2A) centers have turned out to be -305.3 and -400.7 cm(-1), respectively, resulting in a S = 1/2 ground state. The complexes are further characterized by UV-vis, IR, electron paramagnetic resonance, and electrochemical studies.  相似文献   
440.
The crystal structure of a new symmetrical pentadentate N2O3 Schiff base: di[4-(phenylimino)pentan-2-one] ether (H2L) is described. In the solid state, the ligand appears as a keto-imine tautomer, while in DMSO solution, the eneamine form is observed. This ligand coordinates cobalt(II), nickel(II), copper(II) and cadmium(II). The structures of these new complexes are described using infrared and electronic spectroscopy, 1H-n.m.r. and d.s.c. The cyclic voltammograms of the ligand and the complexes in DMF are discussed.  相似文献   
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