Heterobi- and Trimetallic Cerium(IV) tert-Butoxides with Mono-, Di-, and Trivalent Metals (M = K(I), Ge(II), Sn(II), Pb(II), Al(III), Fe(III))

The reaction of Cerium Ammonium Nitrate (CAN) with varying amounts of (KOBu)-Bu-t produced homometallic Ce((OBu)-Bu-t)(4)(NC5H5)(2) (1) and the heterometallic derivative KCe2((OBu)-Bu-t)(10) (3) characterized by X-ray diffraction and NMR spectroscopy. The oxo-alkoxide cluster Ce3O((OBu)-Bu-t)(9) (2) was obtained from a solution of cerium(IV) tetrakis(tert-butoxide) in n-heptane under stringent precautions to avoid any adventitious hydrolysis. Lewis acid-base reactions of in situ generated Ce((OBu)-Bu-t)(4)(THF)(2) (THF = tetrahydrofuran) with bi- and trivalent metal alkoxides [M((OBu)-Bu-t)(x)](n) (M = Ge, Sn; x = 2; n = 2; M = Pb, x = 2; n = 3; M = Al, Fe; x = 3; n = 2) resulted in volatile products of the general formula MCe((OBu)-Bu-t)(4+x) (M = Al (4), Fe (5); x = 3; M = Ge (8), Sn (9), Pb (10); x = 2) in high yields. By dissolving 4 and 5 in pyridine the solvent adducts MCe((OBu)-Bu-t)(7)(NC5H5) (M = Al (6), Fe (7)) were formed, whereas 8 and 9 reacted with Mo(CO)(6) in boiling toluene to yield the termetallic complexes (CO)(5)MoM(mu(2)-(OBu)-Bu-t)(3)Ce((OBu)-Bu-t)(3) (M = Ge (11), Sn (12)). The new compounds were characterized by comprehensive spectral studies, mass spectroscopy, and single crystal X-ray diffraction analysis.