Mössbauer, NMR, geometric, and electronic properties in S = 3/2 iron porphyrins.
Iron porphyrins with the intermediate spin S = 3/2 or admixed with S = 5/2 or 1/2 are models for a number of heme protein systems, including cytochromes c'. The (57)Fe Mossbauer quadrupole splittings and (1)H and (13)C NMR chemical shifts have been found to be useful probes of their electronic states. We present the results of the first successful quantum chemical calculations of the Mössbauer and NMR properties in various S = 3/2 iron porphyrin complexes, covering four-, five-, and six-coordinate states and three commonly seen porphyrin conformations: planar, ruffled, and saddled. Several interesting correlations among these useful experimental spectroscopic probes and geometric and electronic properties were discovered. These results should facilitate future investigations of related heme proteins and model systems.
Department of Chemistry, University of Southern Mississippi, 118 College Drive #5043, Hattiesburg, Mississippi 39406, USA.
Yan
Y
Ling
Yong
Y
Zhang
D004583:Electrons; D006418:Heme / Q000737:chemistry; D007501:Iron; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008665:Metalloporphyrins / Q000737:chemistry*; D008968:Molecular Conformation; D015204:Spectroscopy, Mossbauer / Q000379:methods*
D008665:Metalloporphyrins; D006418:Heme; D007501:Iron