一维有机半导体(BEDT-TTF)_2HgCl_3·TCE与二维有机超导体β-(BEDT-TTF)_2I_3

A Structural Comparison Study between One-dimensional Organic Semiconductor (BEDT- TTF)_2HgCl_3·TCE and Two-dimensional Organic Superconductor β-(BEDT-TTF)_2I_3

用电化学结晶方法合成出一种新的导电分子晶体(BEDT-TTF)_2HgCl_3·TCE,[(BEDT-TTF)=双亚乙基二硫四硫富瓦烯,TCE=1,1,2-三氯乙烷].用四圆X衍射方法确定了它的晶体结构,测得(BEDT-TTF)_2HgCl_3·TCE单晶在bc平面的ln(R/R_0)与T^(-1)呈线性关系.(BEDT-TTF)_2HgCl_3·TCE晶体中,(BEDT-TTF)^(+0.5)阳离子自由基沿b方向等距并肩排列,由S…S分子间相互作用维系,形成一维导电结构;阴离子(HgCl_3)^-也沿b方向形成一维聚合体(HgCl_3)_n^(n-),因而(BEDT-TTF)_2HgCl_3·TCE属一维半导体.为了研究导电分子晶体的导电性与结构的关系,制备了有机超导体β-(BEDT-TTF)_2I_3,讨论了β-(BEDT-TTF)_2I_3的导电性优于(BEDT-TTF)_2HgCl_3·TCE的结构原因.

A new semiconductor of organic crystal (BEDT - TTF)2HgCl3·TCE, [(BEDT - TTF) = bis(ethylenedithio)tetrathiafulvalene, TCE = 1,1,2 - trichloroethane ] has been synthesized by electro ?crystallization method. Its structure was determined by four- circle X- ray diffraction method. ln(R/R0) of its single crystal on bc - plane was measured to have a linear relationship to T-1. In (BEDT - TTF)2HgCl3·TCE crystal, the BEDT - TTF cationic radicals are arranged side - by - side equidistantly forming a kind of one - dimensional structure along the b axis. ( HgCl3)- anions also form another kind of one - dimensional polymers (HgCl3)nn- along this direction. Therefore, (BEDT - TTF)2HgCl3·TCE is an one - dimensional organic semiconductor. In order to reveal the conductivity - structure relationships, we have also synthesized the known organic superconductor (3 - (BEDT - TTF)2I3 and discussed why the conductivity of β - (BEDT -TTF)2I3 is superior to that of (BEDT-TTF)2HgCl3·TCE.