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José R. Mora Rosa M. Domínguez Armando Herize María Tosta Gabriel Chuchani 《Journal of Physical Organic Chemistry》2008,21(5):359-364
The gas‐phase elimination kinetics of 2,2‐diethoxyethyl amine and 2,2‐diethoxy‐N,N‐diethylethanamine (320–380 °C; 40–150 Torr) in a seasoned reaction vessel are homogeneous, unimolecular and obey a first‐order rate law. These elimination processes involve two parallel reactions. The first gives ethanol and the corresponding 2‐ethoxyethenamine. The latter compound further decomposes to ethylene, CO and the corresponding amine. The second parallel reaction produce ethane and the corresponding ethyl ester of an α‐amino acid. The following Arrhenius expressions are given as: For 2,2‐diethoxyethyl amine For 2,2‐diethoxy‐N,N‐diethylethanamine Comparative kinetic and thermodynamic parameters of the overall, the parallel and the consecutive reactions lead to consider two types of mechanisms in terms of a concerted polar cyclic transition state structures. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
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A simple and efficient method for the preparation of a novel soluble chitosan derivative, diethoxy phosphoryl chitosan (PH‐chitosan), has been developed. Ph‐chitosan was characterized by elemental analysis, FT‐IR, NMR, ICP, XRD, TG and SEM, respectively. The chemical identity of PH‐chitosan was determined by FT‐IR and confirmed by NMR, and those results unequivocally demonstrated that diethoxy phosphoryl groups were grafted onto the amino and hydroxyl groups of chitosan. The results of XRD indicated that the crystalline structure of chitosan was destroyed due to the incorporation of diethoxy phosphoryl group resulting in loss of hydrogen bond. The analysis of TG demonstrated that PH‐chitosan was less thermal stable than chitosan. This simple synthetic method provided a new and available approach to prepare a soluble high molecule weight chitosan derivative. 相似文献
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Wei Yong Chun‐Hua Hu Jian‐Min Dou Jie Sun Ke‐Ji Hu Ruo Shui Jin Pei‐Ju Zheng 《中国化学》2001,19(11):1162-1164
Two title nido‐11‐vertex platinaundecaboranes, 7,7‐bis‐(triphenylphosphine‐P)‐8, 10‐diethoxy‐8, 9:10, 11‐bis‐μ‐H‐7‐platina‐nido‐undecaborane‐dichloromethane (I) and 7,7‐bis‐(triphenylphosphine‐P) ‐8, 10‐di(i‐propoxy) ‐8,9:10,11‐bis‐μ‐H‐7‐platina‐nido‐undecaborane (II), were prepared and their structures were determined by single crystal X‐ray diffraction method. Each of them has an 11‐vertex nido‐polyhedral skeleton. {PtB10} cage is substituted by two ethoxy or i‐propoxy groups at 8 and 10 positions, respectively. 相似文献
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