Models of the cytochromes: crystal structures and EPR spectral characterization of low-spin bis-imidazole complexes of (OETPP)Fe(III) having intermediate ligand plane dihedral angles.

Models of the cytochromes: crystal structures and EPR spectral characterization of low-spin bis-imidazole complexes of (OETPP)Fe(III) having intermediate ligand plane dihedral angles. Research Abstract Details 

Research Abstract Table of Contents

Jump to the:

Models of the cytochromes: crystal structures and EPR spectral characterization of low-spin bis-imidazole complexes of (OETPP)Fe(III) having intermediate ligand plane dihedral angles. Abstract Text:

Liliya A Yatsunyk,Alice Dawson,Michael D Carducci,Gary S Nichol,F Ann Walker,

The preparation, EPR spectra, and crystal structures of octaethyltetraphenylporphyrinatoiron(III) having two imidazole, N-benzylimidazole, and N-methylimidazole axial ligands are reported, [(OETPP)Fe(HIm)2]Cl, [(OETPP)Fe(N-BzIm)2]Cl, and [(OETPP)Fe(N-MeIm)2]Cl. Despite large variation in axial ligand size, the unit cell parameters for all complexes are very similar; each structure has the same basic motif, with large voids formed by the extended porphyrin framework (filled by ordered or disordered axial ligands and disordered solvent), which allows differently sized ligands to fit within the same cell dimensions. Each porphyrin core adopts a saddled conformation with absolute value(deltaC(beta)) = 1.13-1.15 A. The dihedral angles between axial ligand planes, delta phi, are far from being either ideal parallel or perpendicular: 30.1 degrees, 57.2 degrees for [(OETPP)Fe(HIm)2]Cl (molecules 1 and 2), 56.8 degrees for [(OETPP)Fe(N-BzIm)(2)]Cl, and 16.0 degrees, 44.6 degrees, 59.6 degrees, and 88.1 degrees for [(OETPP)Fe(N-MeIm)2]Cl, which has disordered axial ligands. Among the complexes of this study, an axial ligand delta phi of 56.8 degrees is found to be the largest "parallel" angle (as defined by the observation of a normal rhombic or Type II EPR signal (N-BzIm, g = 3.08, 2.19, 1.31)), while 57.2 degrees is found to be the smallest "perpendicular" delta phi (as defined by the observation of a "large gmax" or Type I EPR signal (HIm, gmax = 3.24)). From the results of this study, it is clear that the size of the largest g for Types I and II complexes varies continuously, with no break between the two. While the switch in EPR signal type, from Type II to Type I, appears to be very sharp in this study, this may be somewhat artificial based upon limited numbers of examples and the required saddle distortion of the (OETPP)Fe(III) complexes. However, in comparison to several proteins with dihedral angles near 60 degrees and Type II EPR spectra, we may conclude that the switch in EPR signal type occurs near 57 degrees +/- 3-5 degrees.

Models of the cytochromes: crystal structures and EPR spectral characterization of low-spin bis-imidazole complexes of (OETPP)Fe(III) having intermediate ligand plane dihedral angles. Publishing Authors By Initials

LA Yatsunyk,A Dawson,MD Carducci,GS Nichol,FA Walker,

For similar organic chemicals: organometallic compounds research abstracts see: organic chemicals: organometallic compounds research

PUBMED ID PMID:

MEDLINE DATE:

Models of the cytochromes: crystal structures and EPR spectral characterization of low-spin bis-imidazole complexes of (OETPP)Fe(III) having intermediate ligand plane dihedral angles. Journal Published:

PUBLICATION TYPE: Research Support, U.S. Gov't,

Journal: Inorganic chemistry

VOLUME: 45

Page Numbers: 5417-28

Journal Abbreviation:

ISSN: 0020-1669

DAY: 10

MONTH: Jul

YEAR: 2006

Models of the cytochromes: crystal structures and EPR spectral characterization of low-spin bis-imidazole complexes of (OETPP)Fe(III) having intermediate ligand plane dihedral angles. Information

Number of References:

LANGUAGE: eng

NlmUniqueID: 366543

Models of the cytochromes: crystal structures and EPR spectral characterization of low-spin bis-imidazole complexes of (OETPP)Fe(III) having intermediate ligand plane dihedral angles. Keywords Mesh Terms:

KEYWORDS: Organometallic Compounds

MESH TERMS: chemistry

Chemical & Substance for Abstract: Models of the cytochromes: crystal structures and EPR spectral characterization of low-spin bis-imidazole complexes of (OETPP)Fe(III) having intermediate ligand plane dihedral angles. Information

Substance Name: Organometallic Compounds

Registry Number: 0

Grant and Affiliation Information for Models of the cytochromes: crystal structures and EPR spectral characterization of low-spin bis-imidazole complexes of (OETPP)Fe(III) having intermediate ligand plane dihedral angles.

AFFILIATION: Department of Chemistry, University of Arizona, Tucson, Arizona 85721-0041, USA.

Country: United States

AGENCY: United States NIDDK

GRANT: DK-31038

ACRONYM: DK

MEDLINETA: Inorg Chem

REFSOURCE:

DATABASENAME:

ACCESSION NUMBER:

Number Hits: 0

Models of the cytochromes: crystal structures and EPR spectral characterization of low-spin bis-imidazole complexes of OETPPFeIII having intermediate ligand plane dihedral angles Related Publications

• 8-Aminoquinolines: future role as antiprotozoal drugs.
• A patient with jejunostomy liberated from home intravenous therapy after 14 years; contribution of balance studies.
• A petal breakstrength meter for Arabidopsis abscission studies.
• A preliminary investigation of Ehrlichia species in ticks, humans, dogs, and capybaras from Brazil.
• Assignment of the ferriheme resonances of the high-spin forms of nitrophorins 1 and 4 by 1H NMR spectroscopy: comparison to structural data obtained from X-ray crystallography.
• Bone morphogenetic proteins act synergistically with haematopoietic cytokines in the differentiation of haematopoietic progenitors.
• Cerebral beta-amyloid angiopathy in aged squirrel monkeys.
• Characterization of Escherichia coli translesion synthesis polymerases and their accessory factors.
• Conference consensus statement: ethical and research dilemmas for fertility preservation in children treated for cancer.
• Correction of cellular zinc depletion by oral zinc supplementation in elderly subjects.
• Different forms of prolactin have opposing effects on the expression of cell cycle regulatory proteins in differentiated mammary epithelial cells.
• Document classification and searching - A neural network approach.
• Expert commentary.
• In vitro reconstitution of two essential steps in wall teichoic acid biosynthesis.
• In vivo pharmacological resultant analysis reveals noncompetitive interactions between opioid antagonists in the rat tail-withdrawal assay.
• Management of allergic problems in primary care: time for a rethink?
• Models of the cytochromes: crystal structures and EPR spectral characterization of low-spin bis-imidazole complexes of (OETPP)Fe(III) having intermediate ligand plane dihedral angles.
• NMR and EPR studies of chloroiron(III) tetraphenyl-chlorin and its complexes with imidazoles and pyridines of widely differing basicities.
• Refractory headache due to spontaneous intracranial hypotension from a CSF leak at C1-2.
• Sex differences in digit ratio (2D:4D) are disrupted in adolescents with schizotypal personality disorder: altered prenatal gonadal hormone levels as a risk factor.
• Sleep facilitates consolidation of emotional declarative memory.
• Suppression of human immunodeficiency virus type 1 replication by CD8+ cells: evidence for HLA class I-restricted triggering of cytolytic and noncytolytic mechanisms.
• Teaching ergonomics to nursing facility managers using computer-based instruction.
• The effect of baclofen on the cardiovascular system of the rat.
• The effects of acute infection on indices of zinc status.
• The impact of differential patterns of physical violence and stalking on mental health and help-seeking among women with protective orders.
• The microbiology of glue ear in Australian Aboriginal children.
• The use of dermal configurations in the diagnosis of mongolism.
• Therapeutic potential of S179D prolactin--from prostate cancer to angioproliferative disorders: the first selective prolactin receptor modulator.
• [Effects of ob genotype on early development in mice]