title: Coordination studies of bis-strapped-hanging-carboxylate porphyrins. X-ray characterization of a five-coordinate iron(II) complex with a built-in axial base.
abstract: The comparison of two series of preorganized strapped porphyrins, derived from both the alphabetaalphabeta and alphaalphabetabeta conformers of meso-tetrakis(aminophenyl)porphyrin, and the coordination studies of their affinity for O(2) are reported. Both series of ligands bear a proximal built-in axial base and a polar distal side defined by either a hanging malonyl ester or a hanging malonic acid residue. In the alphabetaalphabeta model, the carboxylic acid groups are maintained in an apical location at a fixed distance from the distal oxygen atom of iron-bound O(2). A particular emphasis is placed on the alphaalphabetabeta series, for which the crystal structure of the five-coordinate (S = 2) iron(II) ester complex was determined. In this series, the distal strap can adopt either a tilted conformation or a vertical position over the Fe(II) core, allowing changes in the distance between the carboxylic groups and the bound O(2).
authors.affiliation: ICMV, Université de Rennes 1, Sciences Chimiques de Rennes, UMR CNRS 6226, 35042 Rennes Cedex, France.
authors.forename: Ismail
authors.initials: I
authors.lastname: Hijazi
authors.forename: Thierry
authors.initials: T
authors.lastname: Roisnel
authors.forename: Marc
authors.initials: M
authors.lastname: Fourmigué
authors.forename: Jean
authors.initials: J
authors.lastname: Weiss
authors.forename: Bernard
authors.initials: B
authors.lastname: Boitrel
mesh_terms: D002264:Carboxylic Acids / Q000737:chemistry*; D018360:Crystallography, X-Ray; D005296:Ferrous Compounds / Q000737:chemistry*; D008958:Models, Molecular; D011166:Porphyrins / Q000737:chemistry*
chemical_list: D002264:Carboxylic Acids; D005296:Ferrous Compounds; D011166:Porphyrins