SYNTHESIS AND STRUCTURE OF ORGANOSILICON AND ORGANOGERMANIUM COMPLEXES OF YTTERBIUM (PH3E)2YB(THF)4 WITH YB-SI AND YB-GE BONDS

Complexes (Ph3Si)2Yb(THF)4 (1) and (Ph3Ge)2Yb(THF)4 (2) were synthesis ed by the reactions of Ph3SiCl or Ph3GeCl with ytterbium in THF and ch aracterised by X-ray diffraction. Compounds 1 and 2 have similar centr osymmetrical octahedral structures with a central Yb atom bonded to fo ur oxygen atoms of THF molecules in equatorial positions and two Si (o r Ge) atoms of SiPh3 (or GePh3) fragments in axial positions. In the c rystal of 2 there are two symmetrically independent molecules with the same structure. The Yb-Si and Yb-Ge distances in 1 and 2 are 3.158(2) and 3.170(2), 3.141(2) angstrom, respectively.