“Inhibition of the fac-(RCO2)ReI(CO3)(bis-azine), photodecarboxylation of the carboxylate ligand, RCO2-, when R is a strongly electron donating group: Thermal and Photochemical Properties of Complexes Where R = Ferrocene, 4-(Dimethylamino)benzyl”

M. P. JULIARENA, E. WOLCAN, G. T. RUIZ, R. O. LEZNA, M. R. FÉLIZ , G. FERRAUDI AND J. GUERRERO.

ORGANOMETALLICS

American Chemical Society

Año: 2007 vol. 26 p. 272 - 280

0276-7333

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, 1MLCTRefL, 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 RCO2fac-(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, 1MLCTRefL, 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¢-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, 1MLCTRefL, 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 RCO2fac-(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, 1MLCTRefL, 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¢-bpy) complexes. On a femtosecond to 10 ps time scale, the transient spectra of the singlet Re(I) to L charge-transfer excited states, 1MLCTRefL, 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 RCO21MLCTRefL, 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 RCO23MLCTRefL 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 thechargetransfer 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 the3MLCTRefRCO2. 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 the2 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 the3LLCTRefL, is markedly affected by the positions of the 3MLCTRefRCO2 and 3MLCTRefL excited states. In addition, the low energy of 3LLCTRCO2fL in the3MLCTRefRCO2 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-(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.phen, 2,2¢-bpy) decreases the efficiency of the photodecarboxylation reaction.