QQ客服 官方微博 反馈留言

	手性分子中的宇称破缺:D-和L-丙氨酸的变温中子结构研究; Parity Violations on Molecular Chirality:Neutron Crystal-Structure of D- and L-alanine
	王文清 ; 刘轶男 ; 龚(龙天)
	2004
关键词	宇称破缺 分子手性 中子衍射 D-和L-丙氨酸 Parity violation Molecular chirality Neutron diffraction D- and L-alanine
英文摘要	利用单晶的中子衍射研究295 K和60 K时丙氨酸对映体的结构特征以及由D到L构型转变的可能性.中子衍射数据揭示了变温过程中产生的晶格扭曲和NH+3的扭转.通过分析宇称破缺能差EPV随二面角及扭角的变化,肯定了D-丙氨酸能量高于L-丙氨酸的结论.降温过程中D-和L-丙氨酸的弱氢键的行为的差异表明,可能是由于电弱相互作用宇称不守恒所引起.丙氨酸中子结构再次证实Cα-H…O氢键的存在.然而,比较295 K和60 K(高于和低于丙氨酸相变温度250 K)的中子衍射结构数据,表明并没有发生D型到L型的构型转化,这意味着Salam相变不是传统意义的结构相变.; The role of chirality determines the origin of life that almost all amino acids utilized in living systems are of the L-type. Starting from Z0 interactions, Salam speculated on an explanation in terms of quantum mechanical cooperative and condensation phenomena where the electron-nucleon system has the same status as Cooper-pairing, which could give rise to second-order phase transitions(including D to L transformations) below a critical temperature Tc( ～250 K).Neutron diffraction of single crystal D- and L-alanine was performed to look for the characteristic structural feature above and below the Tc (295 K and 60 K) and the possibility of D- to L-type transformation. Data analysis of the temperature effect on the crystal lattice together with the NH3+ torsional motion, parity-violating energy difference (△ EPV) as a gen bond is discussed. Observation of the behavior of weak hydrogen bonding during the cooling process threw a light on the distinction between D- and L-alanine, which could be attributed to the parity-violating weak interactions. Measurements of the neutron crystal-structure of D-alanine rule out the possibility of configuration transition to L-alanine, which means that Salam phase transition is not a conventional structure transition.; 国家高技术研究发展计划(863计划); 国家自然科学基金; http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000225381400012&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; 11; 1345-1351; 20
语种	中文
出处	SCI ; 万方 ; http://d.g.wanfangdata.com.cn/Periodical_wlhxxb200411012.aspx
出版者	物理化学学报
内容类型	其他
源URL	[http://hdl.handle.net/20.500.11897/80599]
专题	化学与分子工程学院
推荐引用方式 GB/T 7714	王文清,刘轶男,龚(龙天). 手性分子中的宇称破缺:D-和L-丙氨酸的变温中子结构研究, Parity Violations on Molecular Chirality:Neutron Crystal-Structure of D- and L-alanine. 2004-01-01.

个性服务

查看访问统计

相关权益政策

暂无数据

收藏/分享

除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。