Generation of Organoniobium(II) Radicals and Synthesis of Heterometallic Niobium−Mercury Compounds
摘要:
Amalgam reduction of the Nb(III) compounds Cp'Nb-2(Cl)(L) (1, L = CO; 2, L = PMe(3); 3, L = CN(t)Bu) gives rise to the electron-rich Nb(II) radicals Cp'Nb-2(L). lit one case (L = CO) the intermediate radical was observed using ESR spectroscopy. The radicals undergo a facile reaction with elemental mercury to give the heterometallic compounds [Cp'Nb-2(L)]Hg-2, one of which (L = PMe(3)) was characterized crystallographically; since this process is reversible, the mercury adducts constitute convenient sources of the niobium (II) radicals.