title: Role of spin state on the geometry and nuclear quadrupole resonance parameters in hemin complex.
abstract: Theoretical calculations of structural parameters, 57Fe, 14N and 17 O electric field gradient (EFG) tensors for full size-hemin group have been carried out using density functional theory. These calculations are intended to shed light on the difference between the geometry parameters, nuclear quadrupole coupling constants (QCC), and asymmetry parameters (eta Q) found in three spin states of hemin; doublet, quartet and sextet. The optimization results reveal a significant change for propionic groups and porphyrin plane in different spin states. It is found that all principal components of EFG tensor at the iron site are sensitive to electronic and geometry structures. A relationship between the EFG tensor at the 14N and 17 O sites and the spin state of hemin complex is also detected.
authors: Department of Chemistry, Tarbiat Modares University, PO Box: 14115-175, Tehran, Iran.
authors: Hadi
authors: H
authors: Behzadi
authors: David
authors: D
authors: van der Spoel
authors: Mehdi D
authors: MD
authors: Esrafili
authors: Gholam Abbas
authors: GA
authors: Parsafar
authors: Nasser L
authors: NL
authors: Hadipour
mesh_terms: D004583:Electrons; D006427:Hemin / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure
chemical_list: D006427:Hemin