Transition metal complexes containing the S(NtBu)4(2-) tetraimidosulfate dianion.

Three novel metal complexes [(acac)2Cu2(NtBu)4S] (), [Li(thf)4]2[I4Cd2(NtBu)4S] () and [(thf)2Li{(SiMe3)2N}Zn(NtBu)4S] () are prepared from the intended transmetalation of the dilithium complex of N,N',N'',N'''-tetrakis(tert-butyl)tetraimidosulfate [(thf)4Li2(NtBu)4S] (). The two lithium cations are replaced by either the cationic (acac)Cu(ii) moiety, the neutral I2Cd(ii) residue or only a single lithium cation is substituted by the cationic (Me3Si)2NZn(ii) fragment. The complexes show two main results: first the S(NtBu)4(2-) tetrahedron can serve as a ligand to transition metals from the soft Cu(ii) to the harder Zn(ii) at opposite sides and second the S-N bond distances vary only marginally in response to the various metals and the four distances constantly sum up to 6.

Oxidative addition versus substitution reactions of group 14 dialkylamino metalylenes with pentafluoropyridine.

Dialkylamino compounds of group 14 elements (Si, Ge, Sn) in the +2 oxidation state supported by benzamidinate ligands were synthesized and treated with pentafluoropyridine. Two different modes of reactivity were observed, depending on the metal atom and the basicity of the substituent at the metal. Pentafluoropyridine undergoes oxidative addition reaction at the Si(II) and Ge(II) atoms whereas at the Sn(II) atom substitution of the NMe(2) group by the para fluorine of pentafluoropyridine occurs.

Stable silaimines with three- and four-coordinate silicon atoms.

The reactions of silylenes with organic azides are quite diverse, depending on the substituents of the silylene center and on the nature of the azide employed. Elusive silaimine with three-coordinate silicon atom L(1)SiN(2,6-Triip(2)-C(6)H(3)) (5) {L(1) = CH[(C═CH(2))(CMe)(2,6-iPr(2)C(6)H(3)N)(2)] and Triip = 2,4,6-triisopropylphenyl} was synthesized by treatment of the silylene L(1)Si (1) with a sterically demanding 2,6-bis(2,4,6-triisopropylphenyl)phenyl azide (2,6-Triip(2)C(6)H(3)N(3)). The reaction of Lewis base-stabilized dichlorosilylene L(2)SiCl(2) (2) {L(2) = 1,3-bis(2,6-iPr(2)C(6)H(3))imidazol-2-ylidene} with Ph(3)SiN(3) afforded four-coordinate silaimine L(2)(Cl(2))SiNSiPh(3) (6).