Abstract
The charge transfer compounds $(TTF)_4FeCl_3{\cdot}CH_3OH,\;(TTF)_4SbCl_4\;and\;(TTF)_5(SbBr_4)_2{\cdot}CH_3COCH_3$ were prepared from reactions of the TTF (tetrathiafulvalene) and metal halides. The compounds were characterized by spectroscopic (UV,IR, EPR and XPS) methods, magnetic susceptibility and electrical conductivity measurements. The d.c electrical conductivities of the pressed pellets are in the order of $10^{-1}-10^{-3} Scm^{-1}$, which lies in the range of semiconductor region at room temperature. It means that the partially ionized TTF has stacked in low-dimensional chain in each compound. Spectroscopic properties also indicate that TTF molecules are partially ionized and charge transfer has occurred from (TTF)n to Fe(III) center in $(TTF)_4FeCl_3{\cdot}CH_3OH$ whereas to the $-SbX_4^-$ entity in $(TTF)_4SbCl_4\;and\;(TTF)_5(SbBr_4)_2{\cdot}CH_3COCH_3$. The EPR g values are consistent with TTF radical formation and EPR linewidths suggest the delocalization of unpaired electrons along TTF stacks. A signal arised from metal (Fe and Sb) ions were not detected in EPR spectra, indicating that metal ion is in the diamagnetic state in each compound. The diamagnetic state was also examined by the magnetic susceptibility measurement. The magnetic properties reveal the significant interaction between the $TTF^+$ radical cations in the stacks. The oxidation state of metal ions was also investigated by XPS spectra.