Resonance Raman Studies of Mono- and Difluoro-5,10,15,20-tetrakis(pentafluorophenyl)porphyriniron(III)

✍ Scribed by Insook Rhee Paeng; Hakhyun Nam; Sang Woo Lee; Ki-Jung Paeng

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 391 KB
• Volume: 28
• Category: Article
• ISSN: 0377-0486
• DOI: 10.1002/(sici)1097-4555(199704)28:4<229::aid-jrs89>3.0.co;2-9

✦ Synopsis

Resonance Raman (RR) spectra of 5,10,15,20-tetrakis(pentaÑuorophenyl)porphyriniron(III) diÑuoride, which was formed by the reaction between Fe(TPFPP)Cl and tetrabutylammonium Ñuoride [ Fe(TPFPP)F 2 ] -, in various non-aqueous solvents, were obtained with the 406.7 nm (Kr' laser) or 441.6 nm (TBA'F-AE 3H 2 O) (He-Cd laser) excitation. is a six-coordinate iron porphyrin with two polar FeÈF bonds ; its [ Fe(TPFPP)F 2

]band at 456 cm-1 in THF solvent was found for the Ðrst time. While this band was insensitive to m s (F-Fe-F) 56Fe-54Fe isotope substitution, it was downshifted linearly with increasing acceptor number of solvents employed, indicating that electrophilic solvent molecules interact strongly with the electron pairs of the F end to reduce its bond strength. The various spectroscopic results, including NMR and ESR data, suggest that the Fe atom in this complex is in a high-spin complex with a formal oxidation state of + 3.0. In THF solution, Fe(TPFPP)F was also generated as a reaction intermediate and the Raman band at 593 cm-1, which was upshifted to 597 cm-1 upon 56Fe-54Fe isotope substitution (Dm = 4 cm-1), was assigned to the m(Fe-F) stretching mode.