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	分子手性的温度效应:D-丙氨酸的变温X衍射和中子衍射研究(英文); Temperature effect on molecular chirality: X-ray diffraction and neutron diffraction studieg of D-alanine
	王文清 ; 龚 ; 姚楠
	2005
关键词	温度效应 相变 X衍射 中子衍射 D-丙氨酸单晶 宇称破缺能差 temperature effect phase transition X-ray diffraction neutron diffraction D-alanine single crystal parity-violating energy difference
英文摘要	利用X衍射(300,270,250 K)和中子衍射(300,260,250,240 K)研究D-丙氨酸单晶在静态的和动力学的变温过程中的结构特征以及考证Salam预言的由D到L构型转变的可能性.实验发现丙氨酸晶体的空间群P21 21 21对称性没有改变.实验结果否定了构型相变的可能,但是发现在~250 K 有一个微小的、连续的对称性破缺发生.晶体分子振动产生的环电流模型可以用来解释D-和L-丙氨酸单晶直流磁化率和天然旋光角相反的现象,与之相关的中子衍射数据进一步揭示了变温过程中αC-H (2),N -H (1),N -H (4),N -H (6)键长的不同变化.中子衍射还显示了质子移动所导致的...; The results of X-ray diffraction of single crystal D- and L-alanine at 300, 270, 250 K and neutron diffraction of D-alanine at 300, 260, 250, 240 K were presented to look for the static and dynamical structure feature of Salam phase transition. No change in the space group P2(1)2(1)2(1) symmetry was observed. The data rule out the hypothesis of a conventional structural phase transition and reveal a subtle and continuous symmetry breaking that occurs below similar to 250 K. A vibrationally generated electronic ring current model was explained the temperature effect on magnetic susceptibilities and opposite optical rotation phenomena related to the bond lengths of alpha C-H(2), N(1)-H(1), N(l)-H(4), and N(l)-H(6) lengthening (or contraction). A picture of dynamic disorder due to the protonic motion was presented in the intermolecular hydrogen bonds between the NH3+ group and the CO2- group. Salam predicted the enhancement of parity-violating energy difference (PVED) due to temperature-induced phase transition. Tunneling dynamics of amino acids with PVED may provide a bifurcation mechanism for much faster development of homochirality.; http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000230684300015&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701 ; SCI(E); 中文核心期刊要目总览(PKU); 中国科技核心期刊(ISTIC); 中国科学引文数据库(CSCD); 8; 07; 774-781; 21
语种	中文
出处	万方 ; 知网 ; SCI
出版者	物理化学学报
内容类型	其他
源URL	[http://hdl.handle.net/20.500.11897/79901]
专题	化学与分子工程学院
推荐引用方式 GB/T 7714	王文清,龚,姚楠. 分子手性的温度效应:D-丙氨酸的变温X衍射和中子衍射研究(英文), Temperature effect on molecular chirality: X-ray diffraction and neutron diffraction studieg of D-alanine. 2005-01-01.

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