Chemistry of bulky alkoxides of bivalent germanium and tin; structures of gaseous [Sn(OBut)2]2 and crystalline Ge(OCBut 3)2

Abstract

Structural studies of bulky group 4B metal(II) alkoxides reveal that (i) gaseous tin(ii) t-butoxide, (1), is the trans-dimer with a remarkably small endocyclic OSnO angle of 76(2)°, (ii) the crystalline (tri-t-butyl)methoxides of Ge^II, (2a), and Sn^II, (2b), are isomorphous V-shaped monomers, with an exceptionally small OGeO angle in (2a) of 85.9(4)°, and (iii) the ¹¹⁹Sn n.m.r. chemical shifts in C₆D₆ are distinct for alkoxides in which tin has co-ordination number of two (2b), three (1), or four [Snl(Me)(OCBu^t ₃)₂].