New group 14 element(IV) β-diiminates and a Sn(II) analogue

Seven group 14 element(IV) compounds 2–7 have been prepared, derived either (2–5) from the potassium β-diketiminate K(L) [L = {N(Ar)C(Me)}2CH, Ar = C6H3Pri2-2,6] (1) or the known lithium β-dialdiminate Li(L′)] [L′ = {N(Ar)C(H)}2CPh, Ar = C6H3Pri2-2,6]. Treatment of 1 with ButC(O)Cl, Me3SiCl, Ph3SnCl, or Me3SnCl afforded {N(Ar)C(Me)}2C(H)C(O)But (2), [ArNC(Me)C(H)C(Me)N(Ar)SiMe3] (3), [HN(Ar)C(Me)C(H)C(CH2SnPh3)N(Ar)] (4), or (5), respectively. Compounds 4 and 5 are remarkable as they have arisen from a tautomer of 1; crystalline centrosymmetric 5 has a fused tricyclic structure, a central eight-membered ring flanked by two six-membered rings. The compounds [GeCl2(L′)(OGeCl3)] (6) or [SnCl(L′)Me2] (7), the first group 14 metal β-dialdiminates, were obtained from Li(L′) and (GeCl3)2O or Me2SnCl2, respectively. The Sn(II) compound SnCl(L′) (8) was prepared from SnCl2 and K(L′). The molecular structures of the crystalline compounds 3–8 are reported.