Novel monopentamethylcyclopentadienyl alkoxides of La and Ce; X-ray crystal structure of (C5Me5Ce(OCMe3)2)2

Article abstract of DOI:10.1016/0022-328X(89)85334-3

Treatment of monomeric (C5Me5)2LnCH(SiMe3)2 (Ln = La and Ce) compounds with HOCMe3 gives the novel compounds (C5Me5Ln(OCMe3)2)2.An X-ray diffraction study of the cerium analogue reveals a dimeric structure with two symmetrically bridging and two terminal alkoxide ligands in a cis configuration.Crystal data: monoclinic space group P2₁/c, a 13.163(5), b 17.429(4), c 18.988(4) Angstroem, β 100.75(2) deg, V 4279.7 Angstroem³ and Z = 4.Least-squares refinement leads to a final R (based on F) value of 0.044 for 4860 observed reflections.Treatment of (C5Me5)2CeCH(SiMe3)2 with an excess of 2,6-di-t-butylphenol at room temperature gives (C5Me5)2(2,6-di-t-butylphenoxo)cerium.Tris(2,6-di-t-butylphenoxo)cerium and C5Me5H are formed when the mixture is heated to 80 deg.The intermediate (C5Me5)bis(2,6-di-t-butylphenoxo)cerium is not observed under this conditions.