2 Homometallic Alkoxides

X-Ray Crystal Structures of Alkoxo Metal Compounds 239
Figure 4.12 Ca9O36 core structure of
[Ca9⊲OC2H4OMe⊳18⊲HOC2H4OMe⊳2].
Figure 4.13 Ca2( -O)3ON4
core structure of [Ca2( -
OSiPh3)3(OSiPh3)(NH3)4] (SiPh3
groups omitted).
Figure 4.14 Sr3⊲OSiOSiO⊳3 core structure of
[Sr3⊲OSiPh2OSiPh2O⊳3⊲tetraglyme⊳2] (Ph groups
omitted).
[Sr3fO⊲SiPh2O⊳2g3⊲tetraglyme⊳2]. 47 The three Sr atoms are in a nearly linear array
with the central one being six-coordinated (distorted trigonal prismatic) and flanked
by two seven-coordinated ones which are connected by the bridging oxygens of the
disiloxanediolate ligands (Fig. 4.14).
2.2.5 Barium
A few structures of complex barium alkoxides have been determined. With the bulky
triphenylsiloxide ligand the trimer [Ba3⊲ 3-OSiPh3⊳2⊲ -OSiPh3⊳3⊲OSiPh3⊳⊲thf⊳] was