摘要:
IntroductionAmongst the electron-donor molecules employed as components of organic conductors, bis(ethylenedithio)tetrathiafulvalene (ET,Scheme 1) has yielded the largest number of conducting and superconducting cation-radical salts.1The crystal structures of ET salts usually consist of conducting ET layers which alternate with insulating layers of inorganic anions. The rich variety of electronic states in these salts is mainly due to the different types of spatial arrangements that the ET molecules can adopt inside the conducting layers. The inorganic anions are introduced to compensate the charge, but they can also play a crucial role in the interactions with the organic donors by affecting their packing and conformation. Some metal oxide inorganic clusters (polyoxometalates) can play this role as components of hybrid materials.2Schematic representation and atomic numbering scheme of the ET donor (left) and the decaborane anion [B10I10]2−(right).Anions containing halogen atoms can also interact with ET molecules by forming weak hydrogen bonds with the ethylene groups of these donors. A well-known example of the importance of this kind of interaction is shown by Whangboet al.3in the series of superconductors with formula β-(ET)2X (X = IBr2−, AuI2−, I3−). The differences in the superconducting transition temperaturesTcof these salts are explained in terms of the softness of translational and/or librational modes of vibration of the hydrogen⋯anion (C–H⋯X) interactions.We have chosen the halogenated decaborane anion [B10I10]2−(Scheme 1) to be combined with the organic donor ET with the aim of exploring how the size, shape and extramolecular bonding capacity of this anion (viaC–H⋯I contacts with the ethylene groups of the ET molecule) can affect the molecular conformation and packing of the organic donors.
ISSN:1466-8033
DOI:10.1039/b111262g
出版商:RSC
年代:2001
数据来源: RSC