PHOSPHAALKENE DERIVATIVES OF FURANE AND THIOPHENE - SYNTHESIS, CRYSTAL-STRUCTURE, ELECTROCHEMISTRY AND EPR STUDY OF THEIR RADICAL-ANIONS

Two phosphaalkenes containing either a furane or a thiophene ring boun d to the carbon atom of the -P=C < bond have been synthesized. The cry stal structure of the furane derivative has been determined and the el ectrochemistry of both compounds has been investigated. THF solutions of these compounds react at 255 K with a potassium mirror to yield the corresponding radical anions which have been studied by EPR in both t he liquid and solid states. The resulting hyperfine constants are comp ared with the values predicted by ab initio calculations on radical an ions formed from model phosphaalkenes.