Abstract
Resonance Raman (RR) spectra are reported for vanadyl octaethylporphyrin, OV(OEP), tetramesityltetramethylporphyrin, OV(TMTMP), and tetramesitylporphyrin, OV(TMP), and their corresponding π-cation radicals obtained by chemical and electrochemical oxidation. The behavior of the ν2 RR porphyrin “marker band”, which moves to higher frequency upon oxidation of the OV(OEP) and OV(TMTMP) and to lower frequency for OV(TMP), shows that the resultant cation radicals have predominantly 2A1u and 2A2u ground states, respectively. In contrast to earlier work (Macor, K. A.; Czernuszewicz, R. S.; Spiro, T. G. Inorg. Chem. 1990, 29, 1996), it is demonstrated here that the shift of the ν(VO) is insensitive to radical type, behavior which is in agreement with similar studies of the ferryl analogues (Czarnecki, K.; et al. J. Am. Chem. Soc. 1996, 116, 2929 and 4680). It is suggested that the observed downshifts of the ν(VO) previously reported for RR spectra of vanadyl porphyrin π-cation radicals, relative to their neutral parents, are most reasonably ascribed to trans oxo ligand coordination (most probably a water molecule) during low-temperature electrochemical oxidation of the neutral species.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
