VOCl2 Research Articles

Reaktion der Alkoxo-oxovanadium(V)-chloride mit Lithium-alkyl-trimethylsilylamid / Reaction of Alkoxo Oxovanadium(V) Chlorides with Lithium Alkyl Trimethylsilylamide

The aminovanadium(V) compounds VO(OR)2[NR'(SiMe3)] and VO(OR)[NR'(SiMe3)]2 have been prepared by reaction of LiNR'(SiMe3) with VO(OR)2Cl and VO(OR)Cl2, respectively; their spectroscopical data (1H NMR, IR, MS) are reported. All compounds are monomeric in solution. In some cases 1.3 migration of SiMe3 groups from nitrogen to oxygen is observed on heating. Kinetic measurements indicate the rearrangement reaction to be irreversible and intramolecular. The reaction of VO(OR)Cl2 with HNR'(SiMe3) leads to iminovanadium(V) compounds such as R'N = V(OSiMe3)3, R'N = V(OSiMe3)2(OR) and R'N = V(OR)2Cl.

Cyclic substituted dithiocarbamates as ligands. Vanadium(III)and oxovanadium(IV, V) complexes

New vanadium(III) and oxovanadium(VI,V) dithio-carbamato complexes formulated as V(Rdtc)3, V(Rdtc)2Cl, VO(Rdtc)2, VO(Rdtc)Cl2, VO(Rdtc)2Cl and VO(Rdtc)3 (Rdtc = piperidine-, morpholine-, thiomorpholine- orN-methylpiperazinedithiocarbamate) have been characterized by elemental analyses, electrical conductance measurements, spectral (electronic and i.r.) studies and magnetic susceptibility measurements. The dithio ligands exhibit bidentate behaviour in all the complexes. The values for the ligand field parameters were determined from the electronic absorption spectra for the vanadium(III) derivatives; the nephelauxetic parameter is indicative of a weak covalency in the metal-ligand bond. The vanadium(III) tris-derivatives are suggested to have an octahedral geometry,D3symmetry, while the complexes of oxovanadium(IV) may be five-coordinate with a tetragonalpyramidal geometry having the oxygen at the apex. Various tentative stereochemistries are proposed for the oxovanadium(V) derivatives depending on the stoichiometry of the complexes.

Azido- and phosphiniminato-complexes of titanium and vanadium

The azido complexes [Ti(η5-C5H5Cl2(N3)], [Ti(η5-C5H5)2Cl(N3)], [TiCl(N3)(S2CNEt2)2] and [Ti(N3)(S2CNEt2)3] have been prepared from appropriate metal halides by reaction with trimethylsilylazide. The [Ti(η5-C5H5)Cl2(N3)] complex reacts with HC1 and MeCOCl to give HN3 and MeNCO respectively and [Ti(η5-C5H5)Cl3], whereas [Ti(η5-C5H5)Cl2(NPPh3)] is formed on reaction with PPh3. The phosphiniminato complexes [TiCl(NPPh3)(S2CNEt2)2], [TiCl2(NPPh3)2], [VOCl2(NPPh3)], [VOCl(NPPh3)2] and [VCl3(NPPh3)2] have been prepared from the appropriate halido-complexes and Me3SiN=PPh3.