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1.
Synthesis and Crystal Structure of 2-(4-Oxo-3-0- tolyl-3,4-dihydroquinazolin-2-ylthio)acetohydrazide
The title compound was synthesized from 3-(2-methylphenyl)-2-thioxo-2,3-dihy- droquinazolin-4(1H)-one (4) which was prepared from 2-methylaniline in two steps. The structure was supported by the spectroscopic data and unambiguously confirmed by single-crystal X-ray diffraction studies. It crystallizes in the orthorhombic space group Pbca with unit cell dimensions a = 6.687(4), b = 24.788(16), c = 30.453(19) , V = 5048(5) 3 and Z = 8. 相似文献
2.
Arun K. Sarkar Sushama M. Pawar Khushi L. Matta 《Journal of carbohydrate chemistry》2013,32(2):269-278
ABSTRACT Synthesis of three tetrasaccharides, namely, 0-α-L-fucopyranosyl-(1→3)-0-(2-acetamido-2-deoxy-β-D-glucopyranosyl)-(1→3)-0-(β-D-galactopyranosyl)-(1→4)-β-D-glucopyranose (7), 0-α-L-fucopyranosyl-(1→4)-0-(2-acetamido-2-deoxy-β-D-glucopyranosyl)-(1→3)-0-(β-D-galactopyranosyl)-(1→4)-D-glucopyranose (9), and 0-α-L-fucopyransoyl-(1→3)-0-(2-acetamido-2-deoxy-β-D-glucopyransoyl)-(1→6)-0-(β-D-galactopyranosyl)-(1→4)-D-glucopyranose (15) has been described. Their structures have been established by 13C NMR spectroscopy. 相似文献
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Legendre B. Baziard-Mouysset G. Anastassiadou M. Leger J. M. Payard M. 《Journal of Thermal Analysis and Calorimetry》2001,66(2):659-673
The compound 2-(2-benzofuryl) Δ-2 imidazoline, has been studied by DSC, TG, X-ray diffraction and thermomicroscopy.
We shall see that in the case of a study by DSC this compound presents a strange behaviour, which apparently is in contradiction
with the thermodynamic rules. In a case of monotropy, if we have the α-phase (stable) and the γ-phase (metastable), after
melting and cooling only theα-phase could crystallise. But this compound can give, according to the rate of cooling, theγ-phase
metastable. The rate of cooling is of fundamental importance and the monotropic behaviour of this compound will be explained
using the Gibbs function G=f(T) for P=1 atm.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
5.
Abstract FMOC-serine phenacylester was glycosylated with a derivative of the disaccharide α-D-Xylp-(1→3)-β-D-Glcp, and the product was treated with zinc to remove the phenacyl group. The title derivative is useful for synthesis of blood clotting factor IX glycopeptide fragments by the solid-phase approach. 相似文献
6.
I. I. Popov 《Chemistry of Heterocyclic Compounds》1993,29(5):567-574
Upon interaction with caustic in a DMSO medium, 2-chloromethylbenzimidazoles are subjected to cyclodimerization, forming 5H,12H-pyrazino[1,2-a:4,5-a]bis-benzimidazoles; in the presence of nucleophiles (ammonia, amines, anions of -diketones), under the indicated conditions, the products are the corresponding substituted amines or derivatives of pyrrolo[1,2a]benzimidazole.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 664–672, May, 1993. 相似文献
7.
Radiative lifetimes from the first electronically excited state of the amidogen free radical, NH(2)(A?(2)A(1)), are reported for rotational states in selected vibrational levels ν(2)' using laser-induced fluorescence. Thermal collision of argon, Ar(?)((3)P(0), (3)P(2)) metastable atoms in a microwave discharge-flow system with ammonia (NH(3)) molecules produced ground state NH(2)(X?(2)B(1)). The radiative lifetimes for the deactivation of NH(2)(A?(2)A(1)) were determined by measuring the decay profiles of NH(2)(A?(2)A(1)?→?X?(2)B(1)). In addition to the Fermi resonances with the ground state that lengthen the radiative lifetimes, a systematic increase in the radiative lifetimes with rotational quantum number was observed. Furthermore, the average radiative lifetimes of the (0, 9, 0) Γ, τ(1) = 18.65 ± 0.47 μs and (0, 8, 0) Φ, τ(2) = 23.72 ± 0.65 μs levels were much longer than those of the (0, 9, 0) Σ, τ(3) = 10.62 ± 0.47 μs, and (0, 8, 0) Π, τ(4) = 13.55 ± 0.55 μs states suggesting increased mixing of the first electronic excited and the ground states. 相似文献
8.
《Polymer Degradation and Stability》1986,14(3):263-284
A range of phenolic benzotriazolesulfonic acids containing a wide variety of substituents has been synthesized. These compounds protect wool to a significant extent against photo-tendering and, in some cases, against photo-yellowing. The protective effect is dependent on the nature and position of the substituents and is enhanced by (1) locating the sulfonic acid group distant from the hydrogen-bonded phenolic group and (2) placing bulky alkyl groups ortho to this phenolic group. The protective effect of one of the best photostabilizers (II) has been studied in detail and has been found to depend on both the concentration of the photostabilizer and the pH at which it is applied. The photostabilizer (II) also protects dyed wool to some extent against photo-fading as well as against phototendering. 相似文献
9.
《Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy》1986,42(2-3):285-298
The E → B transition of I2 in the region 4400-4000 Å has been studied under high resolution using a 7.3 m vacuum Ebert spectrograph in the 14th order. The values of the constants Be, αe, γe, De and βe of both E and B states determined from the analysis of the rotational structure of nine bands of the system are presented. Vibrational constants of the E state obtained from the analysis of all the bands so far reported and consistent with the precise constants of the B state given in previous work are also presented. The origin of the upper state, E(0+g), of the transition is discussed. 相似文献
10.
《中国化学》2002,(11)
CHAO ,Hui 12 35………………CHEN ,Ming De 1149…………CHEN ,Qing Hua 1340…………CHEN ,Wei 140 1………………CHEN ,Xiao Min 1139…………CHEN ,Xiao Ming 140 6………CHEN ,Zhen Chu 145 7………CHENG ,Jin Sheng 132 6………CHENG ,Peng 12 4 9……………DENG ,Guo Jun 1139…………DesMarteau ,D .D . 12 6 8………DING ,Kui Ling 130 0…………DING ,Yu 1415………………DU ,Chen X… 相似文献
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1mThODUCTIONThioacetalshavebeenwellstudied,becauseoftheirapplicationsinorganicsyn-thesist1i.However,aketohemithioacetalshaveseldombeeninvestigated.Inthispa-Per,wediscussedthecrystalstructureofthetitlecompoundsynthesizedbythereac-tionofabenzoylhemithioacetal(2-hydroxy-2-thiomethylacetoPhenone)and4-fluthroaniline.Sinceknowledgeofthemolecularandcrystalstructureofthetitlecom-PoundwasconsideredusefulforunderstandingthemechanismofthereactionandchemicalproPertiesofaketohemithioacetal,theX-raycr… 相似文献
13.
Hong Zhu MA Bo WANG* College of Chemistry materials science ShaanXi Normal University Xian 《中国化学快报》2003,14(11)
During the past decades enormous progress was made in asymmetric catalytic synthesis, an well-known example is BINAP1, the chiral hydrogenation synthesis of S-(+)-naproxen catalyzed by BINAP-Ru dicarboxylate complexes provides excellent enantioselectivity (up to 99% ee) and good chemical yield (92%), however the pressures is relatively high (135-150 atm) and the (S)-BINAP-Ru(III) complex is very expensive. This problem may present a practical limitation. In recent years new methodolo… 相似文献
14.
A high yielding method for 1,2-cis-β-D-mannosylation by intra-molecular aglycon delivery (IAD) through p-methoxy benzyl ether/acetal exchange and phenylsulfoxide donor is reported, along with its application in iterative assembly of antigenic (1 → 2)-β-pentamannoside domain of phospholipomannan (PLM) of fungal pathogen Candida albicans. 相似文献
15.
Study of (2, 0) Band of A2∏u-X2∑+ g System of N2+ by Optical Heterodyne Detected Velocity Modulation Spectroscopy 下载免费PDF全文
Yan-dan Wu Jin-wen Ben Ling Li Li-juan Zheng Yang-qin Chen Xiao-hua Yang 《化学物理学报(中文版)》2007,20(3):285-290
The (2, 0) band of the A2∏u-X2∑§+g system of N2+ was rotationally studied via optical heterodyne detected velocity modulation spectroscopy. Owing to the high sensitivity of the spectroscopy employed, the frequencies of 310 lines of this band were accurately determined. Moreover, those overlapped lines were also well determined via deconvolution method. A nonlinear least-squares fitting procedure using a standard Hamiltonian was applied to analyze this band. Therefore, the most accurate molecular constants were obtained. 相似文献
16.
TiO2 has been tested to be toxic to DNA under the photo-irradiation of ultraviolet A (UVA). However, in the dark conditions, after several days of treatment with TiO2 in aqueous solution, the interaction between TiO2 and two types of DNA was detected and the mechanisms were studied by the methods of gel-electrophoresis, IR spectroscopy and TEM. The results showed that the DNA would be bound to TiO2; the ratio of binding was related to the concentration and the treating time; the mechanism of binding is related to phosphate groups of DNA. Besides, DNA with different structure showed different degree of binding. These findings showed a new possible way through which the TiO2 nanoparticles interact with DNA. 相似文献
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Solubility of Oxygen in Some 1-1, 2-1, 1-2, and 2-2 Electrolytes as a Function of Concentration at 25°C 总被引:1,自引:0,他引:1
The solubility of oxygen has been measured in a number of electrolytes [(LiCl, KCl, RbCl, CsCl, NaF, NaBr, NaI, NaNO3, KBr, KI, KNO3, CaCl2, SrCl2, BaCl2, Li2SO4, K2SO4, Mn(NO3)3)] as a function of concentration at 25°C. The solubilities, mol (kg-H2O)–1, have been fitted to a function of the molality m (standard deviation < 3mol-kg–1)
where A and B are adjustable parameters and the activity coefficient of oxygen )O2) = [O2]0/[O2]. The limiting salting coefficient, k
S = (ln / m)m=0 = A, was determined for all salts. The salting coefficients for the chlorides and sodium salts showed a near linear correlation with the crystal molar volume V
cryst = 2.52 r
3. The salting coefficients determined from the Scaled Particle Theory were in reasonable agreement with the measured values. The activity coefficients of oxygen in the solutions have been interpreted using the Pitzer equation
where
is a parameter that accounts for the interaction of O2 with cations (c) and anions (a) with molalities m
a and m
c, and
accounts for interactions for O2 with the cation and anion pair (c-a). The
and
coefficients determined for the most of the ions are in reasonable agreement with the tabulations of Clegg and Brimblecombe. The values of
for most of the ions are a linear function of the electrostriction molar volume (Velect = V0 – V
cryst). 相似文献
20.
《Chemical physics letters》1987,135(3):303-306
The zero-point and equilibrium dissociation energies of the hydrogen-bonded dimer H2O…HF have been determined as D0 = 34.3(3) kJmol−1 and De = 42.9 (8) kJmol−1 from absolute intensities of rotational transitions in an equilibrium mixture of H2O, HF and H2O…HF. 相似文献