Synthetic Metals, 41--43 (1991) 2135 2135

NEW EFT CATION-RADICAL SALTS: 5- AND 6- PHASES OF

(EPT)2I 3

N.D. Kushchl E.B. Yagubskii, V.E. Korotkov,

R.P. Shibaeva, M.K. Makova, and R.B. Lyubovskii

USSR Academy of Sciences Institute of Chemical

Physics, Chernogolovka, 142 432 USSR

Two polymorphous modifications of the ethylenedithiopropylene-

dithiotetrathiafulvalene (EPT) salt have been synthesized with

the 13 anion, (~- and 6-phases of (EPT)2I 3. These phase crystals

have been obtained in EFT oxidation by iodine in benzonitrile

at 100o0 with further slow cooling down to room temperature.

Their structures and conductivities have been studied.

(~- (EFT )213 is isostructural with ~-(ET)213 and 6-(EFT)213 is

isostructural with semiconductor 6-(PT)2I 3 and superconductor 6-

(ET)2I 3. The temperature dependence of the 6-(EPT)2I 3 conducti-

vity is of a semiconducting character. The pressure effect on

this phase conductivity has been studied.

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