New superconducting charge-transfer salts (BEDT-TTF)4[A·M(C2O4)3]·C6H5NO2 (A = H3O or NH4, M = Cr or Fe, BEDT-TTF = bis(ethylenedithio)tetrathiafulvalene)
New superconducting charge-transfer salts (BEDT-TTF)4[A·M(C2O4)3]·C6H5NO2 (A = H3O or NH4, M = Cr or Fe, BEDT-TTF = bis(ethylenedithio)tetrathiafulvalene)
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新型超导电荷转移盐 (BEDT-TTF)4[A·M(C2O4)3]·C6H5NO2（A = H3O 或 NH4，M = Cr 或 Fe，BEDT-TTF = 双（乙撑二硫）四硫富瓦烯）
DOI：
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发表时间：
2001
期刊：
影响因子：
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通讯作者：
T. Biggs
中科院分区：
文献类型：
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作者：
S. Rashid;S. Turner;P. Day;J. Howard;P. Guionneau;E. McInnes;F. Mabbs;R. Clark;S. Firth;T. Biggs
本文报道了两种新的BEDT-TTF晶体电荷转移盐--双（亚乙基二硫代）四硫富瓦烯的合成、晶体结构和物理性质。BEDT-TTF在（NH 4）3[Fe（C2 O 4）3]·3 H2O或（NH 4）3[Cr（C2 O 4）3]·3 H2O存在下在C6 H5 NO2中的电化学氧化产生β′′-（BEDT-TTF）4[A·Fe（C2 O 4）3]·C6 H5 NO2 [1]或β′′-（BEDT-TTF）4[A·Cr（C2 O 4）3]·C6 H5 NO2 [2]晶体。
（A = H3O+）
或NH 4+）。在120 K下，解出了[1]的晶体结构，空间群为C2/c;在298和120 K下，解出了[2]的晶体结构，空间群为C2/c。对于[1]，a = 10.273 A，B = 19.949 A，c = 35.030 A，β = 92.97°，V = 7169.6（2）A ~ 3，Z = 8.对于[2]，在298 K时：a = 10.304 A，B = 20.091 A，c = 35.251 A，β = 92.70°，V = 7289.3（2）A ~ 3，Z = 8，
在120 K时，a = 10.283 A，B = 19.917 A，c = 34.939 A，β = 93.30°，V = 7144.4（1）A ~ 3，Z = 8.这两种化合物的晶体结构由BEDT-TTF阳离子层和含有[M（C2 O 4）3]3−、H3 O+或NH 4+和PhNO 2的层交替组成。BEDT-TTF分子排列在β′′堆积基序中，并且三（三羟甲基）金属（III）离子形成在许多分子基磁体中发现的众所周知的蜂窝基序。对晶体进行了SQUID磁强计、拉曼光谱和电子顺磁共振（EPR）测量
的[1]。对[2]的晶体进行了SQUID磁力测定、单晶四探针电导率测量、拉曼光谱、EPR和偏振红外反射。这两种化合物都具有金属到超导转变，[1]的Tc = 6.2K，[2]的Tc = 5.8K。
The syntheses, crystal structures, and physical properties of two new crystalline charge-transfer salts of BEDT-TTF, bis(ethylenedithio)tetrathiafulvalene, containing tris(oxalato)metallate(III) anions of 3d elements are reported. Electrochemical oxidation of BEDT-TTF in the presence of (NH4)3[Fe(C2O4)3]·3H2O or (NH4)3[Cr(C2O4)3]·3H2O in C6H5NO2, yields crystals of β′′-(BEDT-TTF)4[A·Fe(C2O4)3]·C6H5NO2[1] or β′′-(BEDT-TTF)4[A·Cr(C2O4)3]·C6H5NO2[2]
(A = H3O+
or NH4+). The crystal structure of [1] has been solved at 120 K in the monoclinic space group C2/c, and that of [2] in the same space group at 298 and 120 K. For [1], a = 10.273 A, b = 19.949 A, c = 35.030 A, β = 92.97°, V = 7169.6(2) A3, Z = 8. For [2], at 298 K: a = 10.304 A, b = 20.091 A, c = 35.251 A, β = 92.70°, V = 7289.3(2) A3, Z = 8,
and at 120 K a = 10.283 A, b = 19.917 A, c = 34.939 A, β = 93.30°, V = 7144.4(1) A3, Z = 8. The crystal structures of both compounds consist of alternating layers of BEDT-TTF cations and layers containing [M(C2O4)3]3−, H3O+ or NH4+, and PhNO2. The BEDT-TTF molecules are arranged in the β′′ packing motif and the tris(oxalato)metallate(III) ions form the well-known honeycomb motif found in many molecular based magnets. SQUID magnetometry, Raman spectroscopy and electron paramagnetic resonance (EPR) measurements were performed on crystals
of [1]. SQUID magnetometry, single-crystal four-probe conductivity measurements, Raman spectroscopy, EPR and polarised infrared reflectance were performed on crystals of [2]. Both compounds have metal to superconducting transitions with Tc = 6.2 K for [1] and for [2], Tc = 5.8 K.