New BEDT-TTF/[Fe(C5O5)3]3- Hybrid System: Synthesis, Crystal Structure, and Physical Properties of a Chirality-Induced 
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- 作者：Eugenio Coronado ; Simona Curreli ; Carlos Gimé ; nez-Saiz ; Carlos J. Gó ; mez-Garcí ; a ; Paola Deplano ; Maria Laura Mercuri ; Angela Serpe ; Luca Pilia ; Christophe Faulmann ; Enric Canadell
- 刊名：Inorganic Chemistry
- 出版年：2007
- 出版时间：May 28, 2007
- 年：2007
- 卷：46
- 期：11
- 页码：4446 - 4457
- 全文大小：580K
- 年卷期：v.46,no.11(May 28, 2007)
- ISSN：1520-510X
文摘
The paramagnetic and chiral anion [Fe(C5O5)3]3- (C5O52- = croconate) has been combined with the organic donorBEDT-TTF (=ET = bis(ethylenedithio)tetrathiafulvalene) to synthesize a novel paramagnetic semiconductor withthe first chirality-induced 
fchars/alpha.gif" BORDER=0> phase, fchars/alpha.gif" BORDER=0>-(BEDT-TTF)5[Fe(C5O5)3]·5H2O (1), and one of the few known paramagneticmolecular metals, fchars/beta2.gif" BORDER=0 ALIGN="middle">-(BEDT-TTF)5[Fe(C5O5)3]·C6H5CN (2). Both compounds present layers of BEDT-TTF molecules,with the fchars/alpha.gif" BORDER=0> or fchars/beta2.gif" BORDER=0 ALIGN="middle"> packing modes, alternating with layers containing the high-spin S = 5/2 Fe(III) anions and solventmolecules. In the fchars/alpha.gif" BORDER=0> phase, the alternation of the chiral [Fe(C5O5)3]3- anions along the direction perpendicular tothe BEDT-TTF chains induces an alternation of the tilt angle of the BEDT-TTF molecules, giving rise to the observedfchars/alpha.gif" BORDER=0> phase. The fchars/alpha.gif" BORDER=0> phase presents a semiconductor behavior with a high room-temperature conductivity (6 S·cm-1)and an activation energy of 116 meV. The fchars/beta2.gif" BORDER=0 ALIGN="middle"> phase presents a metallic behavior down to ca. 120 K, where acharge localization takes place with a reentrance to the metallic state below ca. 20 K followed by a metal-semiconductor transition at ca. 10 K. The magnetic properties are dominated by the paramagnetic S = 5/2[Fe(C5O5)3]3- anion with an extra Pauli-type paramagnetism in the metallic fchars/beta2.gif" BORDER=0 ALIGN="middle"> phase. The ESR spectra confirm thepresence of the high-spin Fe(III)-containing anion and show a progressive localization in the organic sublatticealong with an antiferromagnetic coupling below ca. 120 K that, in the metallic fchars/beta2.gif" BORDER=0 ALIGN="middle"> phase, could be at the origin ofthe transition from the metallic to the activated conductivity regime. The correlation between crystal structure andconductivity behavior has been studied by means of tight-binding band structure calculations which provide arationalization of the charge distribution and conductivity results.
fchars/alpha.gif" BORDER=0> phase, fchars/alpha.gif" BORDER=0>-(BEDT-TTF)5[Fe(C5O5)3]·5H2O (1), and one of the few known paramagneticmolecular metals, fchars/beta2.gif" BORDER=0 ALIGN="middle">-(BEDT-TTF)5[Fe(C5O5)3]·C6H5CN (2). Both compounds present layers of BEDT-TTF molecules,with the fchars/alpha.gif" BORDER=0> or fchars/beta2.gif" BORDER=0 ALIGN="middle"> packing modes, alternating with layers containing the high-spin S = 5/2 Fe(III) anions and solventmolecules. In the fchars/alpha.gif" BORDER=0> phase, the alternation of the chiral [Fe(C5O5)3]3- anions along the direction perpendicular tothe BEDT-TTF chains induces an alternation of the tilt angle of the BEDT-TTF molecules, giving rise to the observedfchars/alpha.gif" BORDER=0> phase. The fchars/alpha.gif" BORDER=0> phase presents a semiconductor behavior with a high room-temperature conductivity (6 S·cm-1)and an activation energy of 116 meV. The fchars/beta2.gif" BORDER=0 ALIGN="middle"> phase presents a metallic behavior down to ca. 120 K, where acharge localization takes place with a reentrance to the metallic state below ca. 20 K followed by a metal-semiconductor transition at ca. 10 K. The magnetic properties are dominated by the paramagnetic S = 5/2[Fe(C5O5)3]3- anion with an extra Pauli-type paramagnetism in the metallic fchars/beta2.gif" BORDER=0 ALIGN="middle"> phase. The ESR spectra confirm thepresence of the high-spin Fe(III)-containing anion and show a progressive localization in the organic sublatticealong with an antiferromagnetic coupling below ca. 120 K that, in the metallic fchars/beta2.gif" BORDER=0 ALIGN="middle"> phase, could be at the origin ofthe transition from the metallic to the activated conductivity regime. The correlation between crystal structure andconductivity behavior has been studied by means of tight-binding band structure calculations which provide arationalization of the charge distribution and conductivity results.