Bispentamethylcyclopentadienyl uranium(IV) thiolate compounds.: Synthesis and reactions with CO2 and CS2

The bisthiolate uranium complexes [U(Cp*)(2)(SR)(2)] (R = Me,Pr-i, Bu-t, Ph) were synthesized by treatment of [U(Cp*)(2)(Cl)(2)] with NaSR; the crystal structure of [U(Cp*)(2)(SMe)(2)] was determined. Their reactions with CO2 or CS2 gave the insertion derivatives [U(Cp*)(2)(SR)(E2CSR)] (E = O and R = Bu-t; E = S and R = Me, Pr-i or Bu-t) and [U(Cp*)(2)(E2CSR)(2)] (E = O and R = Bu-t; E = S and R = Me or Bu-t); [U(Cp*)(2)((SBu)-Bu-t)((S2CSBu)-Bu-t)] was characterized by its crystal structure. Treatment of this latter with CO2 gave the mixed insertion complex [U(Cp*)(2)((O2CSBu)-Bu-t)((S2CSBu)-Bu-t)]. Thermolysis of the insertion compounds led to the reverse elimination reaction of CO2 and CS2. Reduction of [U(Cp*)(2)((O2CSBu)-Bu-t)(2)] with Na(Hg) afforded the corresponding U(III) anionic complex. (C) 1999 Elsevier Science S.A. All rights reserved.