Portal de Periódicos da CAPES

Ion Pairing in Ti(IV) Trisamidotriazacyclononane Compounds

2005; American Chemical Society; Volume: 44; Issue: 24 Linguagem: Inglês

10.1021/ic0510258

1520-510X

Ana M. Martins, José R. Ascenso, Sı́lvia M. B. Costa, Alberto R. Dias, Humberto Ferreira, José A. B. Ferreira,

Lanthanide and Transition Metal Complexes

[Ti[N(Ph)SiMe2]3-tacn]X complexes (X = Cl, 1; I, 2; PF6, 3; BPh4, 4) were studied by NMR and electron absorption and emission methods, which showed that these compounds exist in bromobenzene and dichloromethane solutions as ion pairs. The significant modifications observed in the proton resonances of tacn in C6D5Br, which follow the sequence BPh(4-) > or = PF(6-) > or = I- approximately Cl-, are a qualitative indication of the strength of the interactions that depend on the anion. The reaction of 2 with LiNMe2 led to [Ti(NPh)[NPh(SiMe2)]2-tacn], 5, that forms upon attack of Me2N- at one SiMe2 group. The formation of 5 is discussed on the basis of the interactions identified in solution.