Vibrational properties of several synthetic heme models studied by Raman-related techniques

Our interest in the compounds lies in their special optical properties which distinguish themselves from typical metalloporphyrins such as heme and alkyl- or aryl-substituted synthetic porphyrins, e.g. octaethylporphyrin (OEP) or tetraphenylporphyrins (TPP). The compounds studied show blue-shifted weak Soret absorption in the near UV, but red-shifted STRONG Q band in the visible region. Resonance Raman spectra with excitations near Q absorption band display quite different enhancement pattern from those observed for the typical heme and model compounds (MOEP and MTPP).