INIFTA   05425
INSTITUTO DE INVESTIGACIONES FISICO-QUIMICAS TEORICAS Y APLICADAS
Unidad Ejecutora - UE
artículos
Título:
Inhibition of the fac-(RCO2)ReI(CO)3(bis-azine) photodecarboxylation of the carboxylate ligand, RCO2-, when R is a strong electron donating group.
Autor/es:
M. P. JULIARENA; G. T. RUIZ; E. WOLCAN; R. O. LEZNA; M. R. FELIZ; G. FERRAUDI; J. GUERRERO
Revista:
ORGANOMETALLICS
Editorial:
American Chemical Society
Referencias:
Lugar: New York; Año: 2006
ISSN:
0276-7333
Resumen:
The photophysical and phtochemical properties of fac-(RCO2)ReI(CO)3L (R = ferrocene, L= phen, 2,2¢-bpy; R= 4-(dimethylamino)benzyl (4-DMAB), L= phen) were investigated with continuous and flash photolyses. Their properties were compared with those of fac-(CH3CO2)ReI(CO)3L (L = phen, 2,2¢-bpy) complexes. On a femtosecond to 10 ps time scale, the transient spectra of the singlet Re(I) to L charge-transfer excited states, 1MLCTRe-L, of fac-(RCO2)ReI(CO)3L (R= ferrocene, 4-DMAB) transform into the spectra of two triplet excited states, the 3MLCTRefL excited state and a Re(I) to RCO2- chargetransfer excited state, 3MLCTRefRCO2. The 3MLCTRefRCO2 and 3MLCTRefL excited states have lifetimes that span 102 ns to several microseconds. The photodecarboxylation of fac-(RCO2)ReI(CO)3L, initiated in ligand-to-ligand charge-transfer excited states, 3LLCTRefL, is markedly affected by the positions of the 3MLCTRefRCO2 and 3MLCTRefL excited states. In addition, the low energy of 3LLCTRCO2fL in the fac-(RCO2)ReI(CO)3L (L = phen, 2,2¢-bpy) complexes, relative to those of fac-(CH3CO2)ReI(CO)3L (L= phen, 2,2¢-bpy) decreases the efficiency of the photodecarboxylation reaction.