Influence of vibrational coupling on resonance Raman spectra of the 18O2 adducts of cobalt(II) “jellyfish” porphyrin-imidazole complexes

✍ Scribed by Leonard Marian Proniewicz

• Book ID: 103956691
• Publisher: Elsevier Science
• Year: 1991
• Tongue: English
• Weight: 861 KB
• Volume: 2
• Category: Article
• ISSN: 0924-2031
• DOI: 10.1016/0924-2031(91)85019-j

✦ Synopsis

The resonance Raman (RR) spectra of the "Oz adducts of the imidazole complexes of a highly protected cobalt "jellyfish" porphyrin are reported. The complex spectral patterns observed in the RR spectra are interpreted as a result of vibrational coupling of the v('~O-~~O) with internal modes of the coordinated imidazole. These spectral patterns depend on temperature, imidazole concentration and the presence of other hydrogen-bond acceptors in solution. The results demonstrate that the formation of an internally hydrogen-bonded imidazole ligand does not cause measurable changes in the inherent v(~~O-~~O) frequency, although it leads to alterations in the RR patterns as a spectroscopic consequence of vibrational coupling of the v('sO-'sO) with two distinct imidazole internal modes that belong to a hydrogen-bonded imidazole axial ligand and its non-hydrogen-bonded analogue. The implication of the RR spectra of oxygenated cobalt-substituted haeme proteins and their model compounds is discussed.