ISSN:
0020-7608
Keywords:
iron-porphyrin
;
density functional calculations
;
oxyheme
;
heme models
;
Car-Parrinello molecular dynamics
;
Chemistry
;
Theoretical, Physical and Computational Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Minimum-energy structures of O2, CO, and NO iron-porphyrin (FeP) complexes, computed with the Car-Parrinello molecular dynamics, agree well with the available experimental data for synthetic heme models. The diatomic molecule induces a 0.3-0.4 Å displacement of the Fe atom out of the porphyrin nitrogen (Np) plane and a doming of the overall porphyrin ring. The energy of the iron-diatomic bond increases in the order Fe(SINGLE BOND)O2 (9 kcal/mol) 〈 Fe(SINGLE BOND)CO (26 kcal/mol) 〈 Fe(SINGLE BOND)NO (35 kcal/mol). The presence of an imidazole axial ligand increases the strength of the Fe(SINGLE BOND)O2 and Fe(SINGLE BOND)CO bonds (15 and 35 kcal/mol, respectively), with few structural changes with respect to the FeP(CO) and FeP(O2) complexes. In contrast, the imidazole ligand does not affect the energy of the Fe(SINGLE BOND)NO bond, but induces significant structural changes with respect to the FeP(NO) complex. Similar variations in the iron-imidazole bond with respect to the addition of CO, O2, and NO are also discussed. © 1998 John Wiley & Sons, Inc. Int J Quant Chem 69: 31-35, 1998
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
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