The synthesis and X-ray structures of ytterbocene(II) complexes containing pendant pyridyl groups,

Metallation of C5H5[C(Me)2CH2C5H4N-2] ( CppyH), C5H4(SiMe3)[{C(Me)2CH2C5H4N-2)-3] ( Cp'pyH), C5H5[C(Me)2C5H4N-2] ( Cppy(s)H), and C5H4[(SiMe3){C(Me)2C5H4N-2}-3] [ Cp'py(s)H] with KH in THF yielded the potassium complexes KCppy (1), KCp'py (2), KCppy(s) (3), or KCp'py(s) (4). Compounds 1-4 were readily converted into their homoleptic solvent-free ytterbium(II) complexes [Yb(Cp'py)2] (5), [Yb(CP'py)2] (6), [Yb(CPpy(s))2] (7) and [Yb(Cp'py(s))2](8). The crystal structures of 5 and 8 show that both of the pyridyl groups in each complex are coordinated to the ytterbium. Some angles in 5 are Cp(1)—Yb—Cp(2) 137.7° and N(1)—Yb—N(2) 100.8(2)°, and the corresponding angles in 8 are Cp(1)—Yb—Cp(2) 136.9° and N(1)—Yb—N(2) 84.0(4)° (where Cp refers to the centroid of the cyclopentadienyl ring)