ORGANOAMIDOOXOLANTHANOIDS AND ARYLOXOLANTHANOIDS .15. ORGANOMETALLIC COMPOUNDS OF THE LANTHANOIDS .116. SYNTHESES OF LOW COORDINATION-NUMBER DIVALENT LANTHANOID ORGANOAMIDE COMPLEXES, AND THE X-RAY CRYSTAL-STRUCTURES OF METHYLSILYL)AMIDO]BIS(TETRAHYDROFURAN)SAMARIUM(II) AND ETHYLSILYL)AMIDO]BIS(TETRAHYDROFURAN)YTTERBIUM(II)

The mercury(II) amide complex Hg[N(SiMe(3))(2,6-iPr(2)C(6)H(3))](2) (1 ) was prepared by reaction of HgBr2 with Li[N(SiMe(3))(2,6-iPr(2)C(6)H (3))] in diethyl ether solvent. Redox transmetallation reactions of 1 with elemental samarium, europium or ytterbium in THF solvent (THF = t etrahydrofuran), generated the novel divalent complexes Ln[N(SiMe(3))( 2,6-iPr(2)C(6)H(3))](2)(THF)(2) with Ln = Sm (2), Eu (3) and Yb (4). 4 was also synthesized by reaction of elemental ytterbium, HgPh(2) and HN(SiMe(3))(2,6-iPr(2)C(6)H(3)) in THF solvent. This generally more co nvenient approach has also been applied to the preparation of Ln[N(SiM e(3))(2)](2)(THF)(2) [Ln = Sm (5), Yb (6)] by reaction of the metals w ith HgPh(2) and HN(SiMe(3))(2). Thermal desolvation of 4 under high va cuum gave Yb[N(SiMe(3))(2,6-iPr(2)C(6)H(3))](2)(THF) (7), whereas unde r identical conditions 6 yielded the solvent-free complex {Yb[N(SiMe(3 ))(2)](2)}(2) (8). The new compounds 1-4 and 7 are hydrocarbon soluble and Yb-171-NMR spectra were recorded for 4, 6, 7 and 8. X-ray crystal structure determinations of 2 and 4 revealed four-coordinate, distort ed tetrahedral metal environments augmented by weak Ln ... ipso-C(aryl ) interactions.