Triscyclopentadienyl uranium thiolates and selenolates

Abstract

Triscyclopentadienyl uranium (IV) thiolates were prepared by two principal methods namely (1) substitution of the chloride group of [U(cp) 3(Cl)] (cp = η-C 5H 5) by Sr − and (2) oxidation of the trivalent precursors [U(cp) 3(THF)] (THF = tetrahydrofuran), [U(C 5H 4SiMe 3) 3] and [U(C 5H 4 tBu) 3] with the disulfide RSSR (R = Me, Et, iPr, tBu or Ph).Similar treatment with MeSeSeMe afforded [U(cp) 3(SeMe)] and [U(C 5H 4SiMe 3) 3(SeMe)]. The crystal structure of [U(cp) 3(SMe)] was determined. Several reactions ofthese complexes are described, namely cleavage of the U-S bond by acidic substrates or iodine, insertion of Cs 2 and CO 2 into the U-S bond, and reduction into the corresponding U(III) anions. The synthesis, structure and reactivity of the thiolate compounds are compared with those of the alkoxide analogues.