Homoleptic titanium compounds

The amido ligand is isoelectronic with the alkyl and alkoxo groups and has the possibility to exhibit N-M ir-interactions in order to stabilize the systems they form. Different synthetic reactions are used to prepare mono-Cp titanium derivatives containing amido ligands. These compounds are normally synthesized by (i) the action of the corresponding amide salt on Cp TiCl3, (ii) displacement of amine from a homoleptic amido titanium compound by a Cp reagent, (iii) dehalosilylation reactions, and (iv) elimination of alkane by reaction of an alkyltitanium compound with amine. 

The homoleptic (see Homoleptic Compound) titanium diene complex (j " -r-BuCH=CHCH=CHBu-t)2Ti (11) has been prepared by the condensation ofelectron-beam vaporized titanium with an excess of 1,4-di-t-butylbuta-1,3-diene" (see Metal Vapor Synthesis of Transition Metal Compounds). The bis-diene dmpe complex Ti(dmpe)( " -C4H6)2Ti (12) has been prepared by the reduction of TiCl4(dmpe) with Na/Hg in the presence of butadiene, and by the reduction of TiCLi with CH2=CHLi in the presence of dmpe. ... 

The homoleptic, bis(trispyrazolylborate)titanium(ll) complex, Tp2Ti (Tp = trispyrazolylborate 203), has been prepared by reaction of 2 equiv. of KTp with TiCl2(TMEDA) (TMEDA = Ar,Ar,Ar, A -tetrarncthylcthylcncdiarninc).122 The dark red, paramagnetic compound has idealized /)v/ symmetry in the solid state and is easily oxidized to the corresponding Ti(m) derivative both electrochemically and chemically with AgPF, 204. Two-electron oxidation to Ti(rv) chalcogenido complexes has been accomplished with pyridine-N-oxide as well as with elemental sulfur and selenium (205, Scheme 31). 

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