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1.
Aslan Esmurziev Nebojša Simić Eirik Sundby Bård Helge Hoff 《Magnetic resonance in chemistry : MRC》2009,47(5):449-452
Complete assignments of 1H‐ and 13C‐NMR resonances of five methyl tetra‐O‐benzoyl‐D‐pyranosides based on 1H, 13C, 2D DQF–COSY, HMQC, HMBC and HSQC–TOCSY experiments have been performed. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
2.
E. J. K. Nilsson M. S. Johnson O. J. Nielsen E. W. Kaiser T. J. Wallington 《国际化学动力学杂志》2009,41(6):401-406
Relative rate techniques were used to study the title reactions in 930–1200 mbar of N2 diluent. The reaction rate coefficients measured in the present work are summarized by the expressions k(Cl + CH2F2) = 1.19 × 10?17 T2 exp(?1023/T) cm3 molecule?1 s?1 (253–553 K), k(Cl + CH3CCl3) = 2.41 × 10?12 exp(?1630/T) cm3 molecule?1 s?1 (253–313 K), and k(Cl + CF3CFH2) = 1.27 × 10?12 exp(?2019/T) cm3 molecule?1 s?1 (253–313 K). Results are discussed with respect to the literature data. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 41: 401–406, 2009 相似文献
3.
The reaction of phosphorus oxychlo‐ ride/phosphorus thiochloride with 2‐(2′‐mercapto‐ phenyl)benzoxazole in 1:1, 1:2, and 1:3 molar ratio in the presence of stoichiometric amounts of triethyl‐ amine has afforded a series of organophosphates. These organophosphates have been characterized by elemental analyses, infrared, 1H NMR, 31P NMR, and mass spectral studies. The antifungal activity of these organophosphates has been evaluated against pathogenic fungi Aspergillus niger and Fusarium oxysporium. The antifungal screening data reveal that these compounds are more fungitoxic than 2‐(2′‐mercaptophenyl) benzoxazole. These organophosphates were also found to be insecticidal when tested against Periplenata americana.© 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:309–315, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20551 相似文献
4.
Noureddine Raouafi Akila Khlifi Khaled Boujlel Mohamed Lamine Benkhoud 《Heteroatom Chemistry》2009,20(5):272-277
The reaction of N‐thioamido amidines 1 with tris(dimethylamino)phosphine or bis(diethylamino)phenylphosphine in refluxing toluene leads to the 1,3,5,2λ3‐triazaphosphorines 2 and 3 , respectively. The condensation results in the release of two molecules of dialkylamine. The sulfuration of the trivalent phosphorus atoms was achieved by the reaction with elemental sulfur, followed by heating in toluene. The structure of the triazaphosphorines 2 and 3 and their thione derivatives 4 and 5 were readily elucidated by means of 1H, 13C, and 31P NMR spectroscopy and mass spectrometry. © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:272–277, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20546 相似文献
5.
Two new steroidal saponins (1 and 2) were isolated from the BuOH fraction of the 70% EtOH extract of the tubes of Smilax china, together with four known analogues, 3–6. The structures of the new compounds were elucidated by means of chemical evidence and spectroscopic analyses, including HR‐MS, IR, 1H‐ and 13C‐NMR, and 2D experiments (1H–1H COSY, HSQC and HMBC). Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
6.
Xiongming Luo Shuhua Qi Hao Yin Zhihui Xiao Si Zhang 《Magnetic resonance in chemistry : MRC》2009,47(12):1110-1114
Four new coumarins, micromelosides A–D, together with four known coumarins were isolated from the stem bark of Micromelum falcatum. The complete assignments of the 1H and 13C NMR chemical shifts for these new compounds were achieved by means of 1D and 2D NMR techniques, including 1H‐1H COSY, HSQC, HMBC and NOE difference. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
7.
Rubén Montalvo‐González Armando Ariza‐Castolo 《Magnetic resonance in chemistry : MRC》2009,47(12):1013-1018
The thermodynamic products (ε‐lactams) of the degradation of ten different spirocyclic oxaziridines were analyzed by 1H and 13C NMR spectroscopy. The preferred conformations were determined by examining the homonuclear spin–spin coupling constant and the chemical shift effects of the N‐substituent and the alkyl group of the aliphatic ring on 1H and 13C NMR spectra. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
8.
Fazuo Wang Tianjiao Zhu Min Zhang Aiqun Lin Weiming Zhu Qianqun Gu 《Magnetic resonance in chemistry : MRC》2010,48(2):155-158
Three new furan and pyran derivatives named aspericins A? C (1–3), as well as a known asperic acid (4), have been isolated from the marine‐derived fungus Rhizopus sp. 2‐PDA‐61. The complete 1H and 13C NMR assignments for the new compounds were carried out using 1H, 13C, DEPT, COSY, HMQC, HMBC, and NOESY NMR experiments. Compounds 1–3 were evaluated for their cytotoxic activities on P388, A549, HL‐60, and BEL‐7420 cell lines by the MTT and SRB methods. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
9.
Four organotin complexes with 2,2′‐bipyridine‐4,4′‐dicarboxylic acid, H2dcbp: (Ph3n)2(dcbp) 1 , [(PhCH2)3n]2(dcbp) ⋅ 2CH3OH 2 , [(Me3Sn)2(dcbp)]n 3 , [(Bu3Sn)2(dcbp)]n 4 have been synthesized. The complexes 1–4 were characterized by elemental, IR, 1H, 13C, 119n NMR, and X‐ray crystallographic analyses. Crystal structures show that complex 1 is a monomer with one ligand coordinated to two triorganotin moieties, and a 1D infinite polymeric chain generates via intermolecular C H⋅⋅⋅N hydrogen bond; complex 2 is also a monomer and forms a 2D network by intermolecular O–H⋅⋅⋅O weak interaction; both of complexes 3 and 4 form 2D network structures where 2,2′‐bipyridine‐4,4′‐dicarboxylate acts as a tetradentate ligand coordinated to trimethyltin and tri‐n‐butyltin ions, respectively. © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:19–28, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20506 相似文献
10.
The variational method with mutilconfiguration interaction wave function is used to obtain the energies, fine structures, and hyperfine structures of high‐lying core‐excited quartet states 1s2lnl' 4Po(m) (m = 1–5) and 1s2pnp 4P(m) (m = 1–5) in Li‐like N4+ and F6+ ions, including the mass polarization and relativistic corrections. Restricted variational method is carried out to extrapolate a better energy. The oscillator strengths, lifetime, wavelengths, fine structure, and hyperfine structure for this system are also investigated to compare with other theoretical and experimental data in the literature. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010 相似文献
11.
Malek Taher Maghsoodlou Reza Heydari Nourallah Hazeri Sayyed Mostafa Habibi‐Khorassani Mahmoud Nassiri Marjan Ghasemzadeh Jaber Salehzadeh Zahra Gharechaei 《Heteroatom Chemistry》2009,20(4):240-245
Aromatic amine phosphonato esters 4a–d were obtained in excellent yields from the 1:1:1 addition reaction between triphenyl phosphite and dimethyl acetylenedicarboxylate in the presence of NH‐aromatic amines such as 2‐aminobenzophenone, 2‐aminoacetophenon, methyl‐2‐aminobenzoate, and 2‐aminobenzonitrile. In the recent works, the assignments of the configuration of 4a–d corresponding to the three‐bond carbon‐phosphorus coupling, 3Jpc, was determined on the basis of coupling constants by the Karplus equation as 2R *, 3R *or 2S *, 3S * while they were 2R *, 3S * or 2S *, 3R * in our previous works in the presence of same solvent. © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:240–245, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20541 相似文献
12.
In Kyu Moon Chil‐Sung Choi Nakjoong Kim 《Journal of Polymer Science.Polymer Physics》2009,47(17):1695-1702
Poly[N‐(2‐ethylhexyl)‐3‐vinylcarbazole has been synthesized by radical polymerization from N‐(2‐ethylhexyl)3‐vinyl‐carbazole. The 50‐μm thick photorefractive device containing 30 wt % piperidin‐4‐ylbenzylidene‐malononitrile showed a diffraction efficiency of 40% of 50 V/μm, which corresponded to a Δn of 0.8 × 10?3. The photorefractive response time was τ1 = 0.6 s. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 1695–1702, 2009 相似文献
13.
Four new oligosaccharides (1–4), one new pregnane glycoside (5), and one new cardiac glycoside (6) were isolated from the roots of Periploca forrestii Schltr. (Asclepiadaceae), a traditional Chinese medicine used for the treatment of rheumatoid arthritis and wounds. Their structures were characterized on the basis of extensive analysis of NMR (1H, 13C NMR, 1H‐1H COSY, HSQC, HMBC, TOCSY and ROESY) spectra. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
14.
Hui Zhao Wang Zhang Yuan Ju Mei Li Tang Xiao Qing Liu Ji Ming Yan Xiao Yuan Shen Jing Zhi Sun Anjun Qin Ben Zhong Tang 《Journal of polymer science. Part A, Polymer chemistry》2009,47(19):4995-5005
Phenylacetylene derivatives containing carbazole ( 1 ) and fluorene ( 2 ) moieties were polymerized by [Rh(nbd)Cl]2 into corresponding polymers P 1 and P 2 of high molecular weights (Mw ~ 150 × 103–465 × 103) in high yields (up to 98%). The polymers were characterized by NMR, IR, UV, PL, and CV techniques. Hybrids of the polymers with multiwalled carbon nanotubes (MWNTs) were prepared by simply mixing the two components in common organic solvents such as dichloromethane. The solvating power of the polymer carrying the electron‐donating carbazolyl pendant (P 1 ) is stronger than that of its counterpart carrying fluorenyl pendant (P 2 ), due to the stronger donor–acceptor (D–A) interaction between the P 1 chains and the MWNT walls. This work clearly manifests that D–A effect plays an important role in the polymer‐aided MWNT dispersion in organic solvents. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 4995–5005, 2009 相似文献
15.
Sergey V. Fedorov Leonid B. Krivdin Yury Yu. Rusakov Igor A. Ushakov Natalia V. Istomina Natalia A. Belogorlova Svetlana F. Malysheva Nina K. Gusarova Boris A. Trofimov 《Magnetic resonance in chemistry : MRC》2009,47(4):288-299
Theoretical energy‐based conformational analysis of bis(2‐phenethyl)vinylphosphine and related phosphine oxide, sulfide and selenide synthesized from available secondary phosphine chalcogenides and vinyl sulfoxides is performed at the MP2/6‐311G** level to study stereochemical behavior of their 31P–1H spin–spin coupling constants measured experimentally and calculated at different levels of theory. All four title compounds are shown to exist in the equilibrium mixture of two conformers: major planar s‐cis and minor orthogonal ones, while 31P–1 H spin–spin coupling constants under study are found to demonstrate marked stereochemical dependences with respect to the geometry of the coupling pathways, and to the internal rotation of the vinyl group around the P(X)‐C bonds (X = LP, O, S and Se), opening a new guide in the conformational studies of unsaturated phosphines and phosphine chalcogenides. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
16.
The kinetics and mechanism for the reaction of NH2 with HONO have been investigated by ab initio calculations with rate constant prediction. The potential energy surface of this reaction has been computed by single‐point calculations at the CCSD(T)/6‐311+G(3df, 2p) level based on geometries optimized at the CCSD/6‐311++G(d, p) level. The reaction producing the primary products, NH3 + NO2, takes place via precomplexes, H2N???c‐HONO or H2N???t‐HONO with binding energies, 5.0 or 5.9 kcal/mol, respectively. The rate constants for the major reaction channels in the temperature range of 300–3000 K are predicted by variational transition state theory or Rice–Ramsperger–Kassel–Marcus theory depending on the mechanism involved. The total rate constant can be represented by ktotal = 1.69 × 10?20 × T2.34 exp(1612/T) cm3 molecule?1 s?1 at T = 300–650 K and 8.04 × 10?22 × T3.36 exp(2303/T) cm3 molecule?1 s?1 at T = 650–3000 K. The branching ratios of the major channels are predicted: k1 + k3 producing NH3 + NO2 accounts for 1.00–0.98 in the temperature range 300–3000 K and k2 producing OH + H2NNO accounts for 0.02 at T > 2500 K. The predicted rate constant for the reverse reaction, NH3 + NO2 → NH2 + HONO represented by 8.00 × 10?26 × T4.25 exp(?11,560/T) cm3 molecule?1 s?1, is in good agreement with the experimental data. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 41: 678–688, 2009 相似文献
17.
Density functional study of structural and electronic properties of maximum‐spin n+1Aun−1Ag clusters
Zhen‐Yi Jiang Yu‐Qin Hou Kuo‐Hsing Lee San‐Yan Chu 《International journal of quantum chemistry》2009,109(6):1348-1356
The structures and relative stabilities of high‐spin n+1Aun?1Ag and nAun?1Ag+ (n = 2–8) clusters have been studied with density functional calculation. We predicted the existence of a number of previously unknown isomers. Our results revealed that all structures of high‐spin neutral or cationic Aun?1Ag clusters can be understood as a substitution of an Au atom by an Ag atom in the high‐spin neutral or cationic Aun clusters. The properties of mixed gold–silver clusters are strongly sized and structural dependence. The high‐spin bimetallic clusters tend to be holding three‐dimensional geometry rather than planar form represented in their low‐spin situations. Silver atom prefers to occupy those peripheral positions until to n = 8 for high‐spin clusters, which is different from its position occupied by light atom in the low‐spin situations. Our theoretical calculations indicated that in various high‐spin Aun?1Ag neutral and cationic species, 5Au3Ag, 3AuAg and 5Au4Ag+ hold high stability, which can be explained by valence bond theory. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009 相似文献
18.
The nonlinear optical property of new polyester has been studied via second harmonic generation (SHG). The values of electro‐optic coefficients, d33 and d31, of the poled polymer film were 3.15 × 10 ?7 and 1.5 × 10?7 esu, respectively. Thermal behavior of this polyester was studied through thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). 4‐di‐(2′‐hydroxyethoxy)‐4‐diphenyl‐hydrazonomethyl was synthesized from the reaction of 3,4‐dihydroxy‐4‐diphenyl‐hydrazonomethyl with 2–chloro–1‐ethanol in a 1:2 mole ratio and subsequently reacted with terephthaloyl chloride (TPC) in the presence of pyridine, as catalyst, to produce the new nonlinear polyester. The chemical structures of the resulting monomers and polymer were characterized by CHN analysis, 1H‐NMR, FT‐IR, and UV–Vis spectroscopy. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
19.
Julien Nicolas Ségolène Brusseau Bernadette Charleux 《Journal of polymer science. Part A, Polymer chemistry》2010,48(1):34-47
Nitroxide‐mediated controlled/living free‐radical polymerization of methyl methacrylate initiated by the SG1‐based alkoxyamine BlocBuilder was successfully performed in bulk at 80–99 °C with the help of a very small amount of acrylonitrile (AN, 2.2–8.8 mol %) as a comonomer. Well‐defined PMMA‐rich P(MMA‐co‐AN) copolymers were prepared with the number‐average molar mass, Mn, in the 6.1–32 kg mol?1 range and polydispersity indexes as low as 1.24. Incorporation of AN in the copolymers was demonstrated by 1H and 13C NMR spectroscopy, and its effect on the chain thermal properties was evaluated by DSC and TGA analyses. Investigation of chain‐end functionalization by an alkoxyamine group was performed by means of 31P NMR spectroscopy and chain extensions from a P(MMA‐co‐AN)‐SG1 macroinitiator. It demonstrated the very high proportion of SG1‐terminated polymer chains, which opened the door to block copolymer synthesis with a high quality of control. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 34–47, 2010 相似文献
20.
Liliany Espitia Ruby Meneses Rosa M. Dominguez Maria Tosta Armando Herize Jesus Lezama Jennifer Lafont Gabriel Chuchani 《国际化学动力学杂志》2009,41(3):145-152
The gas‐phase elimination kinetics of ethyl 2‐furoate and 2‐ethyl 2‐thiophenecarboxylate was carried out in a static reaction system over the temperature range of 623.15–683.15 K (350–410°C) and pressure range of 30–113 Torr. The reactions proved to be homogeneous, unimolecular, and obey a first‐order rate law. The rate coefficients are expressed by the following Arrhenius equations: ethyl 2‐furoate, log k1 (s?1) = (11.51 ± 0.17)–(185.6 ± 2.2) kJ mol?1 (2.303 RT)?1; ethyl 2‐thiophenecarboxylate, log k1 (s?1) = (11.59 ± 0.19)–(183.8 ± 2.4) kJ mol?1 (2.303 RT)?1. The elimination products are ethylene and the corresponding heteroaromatic 2‐carboxylic acid. However, as the reaction temperature increases, the intermediate heteroaromatic carboxylic acid products slowly decarboxylate to give the corresponding heteroaromatic furan and thiophene, respectively. The mechanisms of these reactions are suggested and described. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 41: 145–152, 2009 相似文献