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141.
142.
根据对应原理,得到了类氢原子能态平均寿命半经典的计算公式τ(n,l),然后利用相对论单通道量子数亏损理论进行推广,得到用来计算考虑总角动量J的激发态寿命公式τ(n,l,l+1/2)和τ(n,l,l-1/2),利用单通道量子数亏损理论得到了碱金属原子n、l远大于1时激发态寿命的半经典公式τ(n.l)=τ0(m+M/nm/v/+M)2v7l(l+1/2)/n4,其计算结果和实验数据符合的很好. 相似文献
143.
ABSTRACTThe reaction of formic acid (HCOOH) with chlorine atom and amidogen radical (NH2) have been investigated using high level theoretical methods such BH&HLYP, MP2, QCISD, and CCSD(T) with the 6–311?+?G(2df,2p), aug-cc-pVTZ, aug-cc-pVQZ and extrapolation to CBS basis sets. The abstraction of the acidic and formyl hydrogen atoms of the acid by the two radicals has been considered, and the different reactions proceed either by a proton coupled electron transfer (pcet) and hydrogen atom transfer (hat) mechanisms. Our calculated rate constant at 298?K for the reaction with Cl is 1.14?×?10?13?cm3?molecule?1?s?1 in good agreement with the experimental value 1.8?±?0.12/2.0?×?10?13?cm3?molecule?1?s?1 and the reaction proceeds exclusively by abstraction of the formyl hydrogen atom, via hat mechanism, producing HOCO+ClH. The calculated rate constant, at 298?K, for the reaction with NH2 is 1.71?×?10?15?cm3?molecule?1?s?1, and the reaction goes through the abstraction of the acidic hydrogen atom, via a pcet mechanism, leading to the formation of HCOO+NH3. 相似文献
144.
Yong Sun Bo-Qiao Fu Ming-Wu Ding 《Phosphorus, sulfur, and silicon and the related elements》2013,188(6):1437-1443
The isothiocyanates 2, obtained from aza-Wittig reactions of vinyliminophosphoranes 1 with CS 2 , reacted with hydrazine to give 3-amino-2-thioxo-4-imidazolidinones 4. One-pot reactions of 4, aromatic isocyanates, Ph 3 P, C 2 Cl 6 , and Et 3 N generated imidazo[2,1-b]-1,3,4-thiadiazol-5(6H)-ones 7. Compound 7 exhibited good fungicidal activities, especially against Sclerotinia sclerotiorum de Bary and Botrytis Cinerea Pers. 相似文献
145.
Abstract Novel, diethyl 1-(isothiocyano)alkylphosphonates 3 have been efficiently synthesized via a one-pot reaction of diethyl 1-azidoalkylphosphonates 1 with triphenylphosphine, followed by in situ transformation of thus formed phosphazenes 2 with carbon disulfide. Application of the title compounds in the synthesis of diethyl (N-phenylthioureido)- and (benzothiazol-2-ylamino)methylphosphonates was also described. 相似文献
146.
Qingmin Wang Runqiu Huang 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1):173-179
Abstract 1-Oxo-4-chlorocarbony1-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane (5) was obtained from phosphorus oxychloride. Benzyl chloroformate was synthesized by the reaction of benzyl alcohol and triphosgene in good yield for the first time. N-r-Butyl-N-benzoylhydrazine(II) was prepared in a new and convenivent procedure with good yield. The reaction of 5 and II proceeded smoothly in the presence of sodium carbonate and afforded the desired compound 13 in good yield, while in the presence of triethylamine, the elimination of butyl was observed and afforded the compound 12. 相似文献
147.
148.
DIHALOCARBENE ADDITION TO ARYLSUBSTTTUTED VINYL PHOSPHATES UNDER PHASE TRANSFER CATALYTIC CONDITIONS
Imre Petneházy György Keglevich László Tőke 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-2):77-82
Abstract Dihalocarbene addition to aryl-substituted vinyl phosphates was carried out both in solid-liquid and in liquid-liquid two phase systems. The dihalocyclopropane adducts of vinyl phosphates could be obtained in better yield using dihalocarbenes generated by the latter method and no hydrolysis of the vinyl phosphate and of the adduct occurred under these circumstances. Eighteen new vinyl phosphate-dihalocarbene adducts were synthetized and characterized. 相似文献
149.
Mariusz Urbaniak Agnieszka Pedrycz Barbara Gawdzik Alicja Wzorek 《Supramolecular chemistry》2013,25(12):777-781
The conditions for synthesis of mono-, di- and trifunctionalised resorcinarenes by catalysed Mannich reaction are described. A series of these compounds are functionalised with different functional groups. 相似文献
150.
Jean Guillon Jean-Michel Leger Cecilia Dapremont Lou Apollonia Denis Pascal Sonnet Stéphane Massip 《Supramolecular chemistry》2013,25(5):319-329
The synthesis of new 25,27-dialkyloxy-5,17-diarylcalix[4]arenes-crown-6 1a–f in 1,3-alternate conformation by Suzuki cross-coupling reaction is reported. Their conformation was determined using 1H, 13C, 2D NMR and ROESY analysis, and X-ray crystallography. Extraction experiments using a two-phase solvent method involving sodium, potassium or cesium picrate showed good extraction of the cesium cation. The X-ray crystal structures of 1,3-alternate 25,27-dipropoxy-5,17-diphenylcalix[4]arene-crown-6 ether 1a and its cesium picrate complex were established. Solid-state data were used to determine the complexation behavior of these new ligands. The efficiency of calixarenes 1a–f for cesium ion extraction could be ascribed to the rigidity and flatness linkages caused by the aryl groups at the lower rim of the aromatic moieties in the calixarene skeleton. In addition, the introduction of these aromatic moieties in positions 5 and 17 enhanced the solubility of the metal complexes in organic media. 相似文献