Otro
Syntheses and luminescent properties of tetrahedral nickel(0) complexes
Registro en:
Inorganica Chimica Acta, v. 255, n. 1, p. 53-58, 1997.
0020-1693
10.1016/S0020-1693(96)05335-2
WOS:A1997WK73100008
2-s2.0-0041107233
Autor
Frem, Regina Célia Galvão
Massabni, Antonio Carlos
Massabni, A. M G
Mauro, Antonio Eduardo
Resumen
Tetrahedral nickel(0) complexes [NiL4], [Ni(dppe)2] and [Ni(CO)2(SbPh3)2] (L=AsPh3, SbPh3, P(OPh)3, dppe=1,2-bis(diphenylphosphino)ethane) were prepared by reduction of NiCl2·6H2O with NaBH4 under N2 or CO atmosphere in the presence of the ligand. The complex [Ni(SbPh3)4] was also obtained by electrolysis at -1.3 V (Ag/Ag+), under a platinum gauze, of the system NiCl2·6H2O/SbPh3 (molar ratio=1:4). These complexes, both in the solid state and in solution, show an orange emission at room temperature, when excited with UV radiation. A qualitative molecular orbital diagram for the [NiL4] complexes is proposed. Electronic absorption spectra of the complexes show bands near 400 nm assigned as MLCT π*2e←d2t2. A 1A1←3T1 transition is suggested for the emission observed in these systems. Lifetimes in microsecond range were estimated from time-resolved emission spectra. Spectroscopic properties of the free ligands have also been investigated.