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	1. Comparative study of the hydrogen-bonded complexes of
	Zhang WenHua,Bi Shi
	Chemistry 14 January 2009
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	Abstract:The hydrogen-bonded complexes of water with eight amino acids (Pro, Hyp, Ser, Glu, Arg, Lys, Gly and Asp) found frequently in collagen were studied. The structures, stability and vibrational spectra of the hydrogen-bonded complexes have been studied by using DFT calculations. Full geometry optimization has been performed for the studied complexes by B3LYP/6-31+G(d) and B3LYP/6-311++G(d,p) calculations. The optimized geometric parameters and interaction energies for various complexes at two levels were estimated. Finally, the vibrational spectra of these complexes were also investigated. Having in mind the hydrogen bonds formed by C=O and N–H groups of the backbone and polar amino acid side chains in collagen, the hydrogen-bonded complexes can be ordered according to their stability as follows: Arg > Glu > Ser > Asp > Pro > Lys > Hyp > Gly. The BSSE corrected interaction energies suggest that the interactions of Pro, Lys, Hyp and Gly with water are similar. The B3LYP/6-311++G(d,p) calculations show the frequency red-shift in hydrogen bond donor modes and an increase of the IR intensity of the νOH vibration of H2O in the complexes A4, G3, N4, P2, L3, Hp4, Gly1 and S3 beyond thirty times.
	TO cite this article:Zhang WenHua,Bi Shi. Comparative study of the hydrogen-bonded complexes of[OL].[14 January 2009] http://en.paper.edu.cn/en_releasepaper/content/27836


	2. Theoretical Study on the Pyrolysis of Methyl tert-butyl Ether (MTBE)
	Taichang Zhang,Lidong Zhang,Jing Wang,Tao Yuan,Xin Hong,Fei Qi
	Chemistry 05 January 2009
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	Abstract:The pyrolysis pathways of MTBE have been investigated using the G3B3 method. Basing on the theoretical calculation, the pyrolysis channels are provided, especially for primary pyrolysis reactions. The primary decomposition pathways include formation of methanol and isobutene, CH4 elimination, H2 elimination and C—H, C—C, C—O bond cleavage reactions. Among them, the formation channel of methanol and isobutene is the lowest pathway in energy, which is in accordance with our experimental observation. Furthermore, the secondary pyrolysis pathways have been calculated as well including decomposition of tert-butyl radical, isobutene, methanol and acetone. The radicals play an important role in the formation of pyrolysis products, for example, tert-butyl radical and allyl radical are major precursors for the formation of allene and propyne. Although some isomers (isobutene and 1-butene, allene and propyne, acetone and propanal) are identified in our experiment, these isomerization reaction pathways occur merely at the high temperature due to their high activation energies. The theoretical calculation can explain the experimental results and shed further light on the thermal decomposition pathways.
	TO cite this article:Taichang Zhang,Lidong Zhang,Jing Wang, et al. Theoretical Study on the Pyrolysis of Methyl tert-butyl Ether (MTBE)[OL].[ 5 January 2009] http://en.paper.edu.cn/en_releasepaper/content/27311


	3. Cytosine Adsorption on Graphene Introducing Dopant: A First-Principles Study
	Yong-Hui Zhang,Guo-Ping Wu,Kai-Ge Zhou,Ke-Feng Xie,Cai-Hong Liu,Hao-Li Zhang,Yong Peng,Yu-Qing Xiong
	Chemistry 05 January 2009
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	Abstract:The adsorption of cytosine on graphene surface is studied using density functional theory with local density approximation. The cytosine is physisorbed onto graphene through π-π interaction, with a binding energy around -0.39 eV. Due to the weak interaction, the electronic properties of graphene show little change upon adsorption. The cytosine/graphene interaction can be strongly enhanced by introducing metal atoms. The binding energies increase to -0.60 and -2.31 eV in the presence of Li and Co atoms, respectively. The transport behavior of an electric sensor based on Co-doped graphene shows a sensitivity one magnitude higher than that of a similar device using pristine graphene. This work reveals that the sensitivity of graphene-based bio-sensors could be drastically improved by introducing appropriate metal atoms.
	TO cite this article:Yong-Hui Zhang,Guo-Ping Wu,Kai-Ge Zhou, et al. Cytosine Adsorption on Graphene Introducing Dopant: A First-Principles Study[OL].[ 5 January 2009] http://en.paper.edu.cn/en_releasepaper/content/27281


	4. Annular-addition of Methylenecyclopropanes with 1,3-Dicarbonyl Compounds free radical: a DFT Study
	Zhang Baohui,Li Ming,Li Ying,Wang Silei,Fu Dan
	Chemistry 28 June 2006
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	Abstract:In the present work, the density functional theory (DFT) is employed to study the mechanism of the annular-addition of methylenecyclopropanes (MCPs) with 1,3-dicanbonyl compounds free radical. All the predicted intermediates and the transition states are optimized completely at the B3LYP/6-311G(d,p) level. As shown, this annular-addition process is endothermic. The chiral-determining step is the formation of the chiral free radical complexes. The dominant products predicted in theoretically are the derivates of pyran.
	TO cite this article:Zhang Baohui,Li Ming,Li Ying, et al. Annular-addition of Methylenecyclopropanes with 1,3-Dicarbonyl Compounds free radical: a DFT Study[OL].[28 June 2006] http://en.paper.edu.cn/en_releasepaper/content/7371

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