Pentacoordinate iron(III) porphyrin carboxylates: Synthesis, physicochemical characteristics and x-ray crystal structure of acetato(5, 10, 15, 20-tetraparatolylporphyrinato) iron(III)

• Published in: Polyhedron Vol. 3; no. 6; pp. 651 - 659
• Main Authors: Oumous, Hassan, Lecomte, Claude, Protas, Jean, Cocolios, Panayotis, Guilard, Roger
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 1984; New York, NY Elsevier Science
• Subjects: Chemistry; Condensed matter: structure, mechanical and thermal properties; Coordination compounds; Exact sciences and technology; Inorganic chemistry and origins of life; Inorganic compounds; Metal complexes; Physics; Preparations and properties; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; Molecular structure; Transition metal Compounds; Organic ligand; Experimental study; Trivalent metal Complexes; X ray diffraction; Inorganic compound; Magnetic susceptibility; Iron III Complexes; Complexes Mixed; Preparation; Carboxylate; Metalloporphyrin; Infrared spectrum; EPR spectrum; NMR spectrum; Crystalline structure
• ISSN: 0277-5387
• DOI: 10.1016/S0277-5387(00)88002-X

Carboxylatoiron(III) porphyrins have been synthesised by the action of carboxylic acids on the [(por)Fe] 2O dimers. 1H NMR and ESR data of the isolated products are in accordance with pentacoordinate high spin 5/2 ferric complexes, the iron atom being displaced out of the plane of the porphyrin ligand. IR spectra show ν(CO) and ν(CO) bands separated by 356–409 cm −1. The magnitude of this separation suggests coordination between the metal centre and the carboxylate group via one oxygen atom. Magnetic susceptibility measurements from 5 to 120 K lead to the value of μ = 5.88 B.M.. The X-ray structure of acetato (5, 10, 15, 20-tetra p-tolyporphyrinato) iron(III) confirms the above deductions. (t p MePP) Fe(CO 2CH 3). 0.5 CH 3COOH crystallises in the I2/c space group with unit cell parameters a = 24.464(8), b = 9.332(3), c = 37.174(4) Å, β = 90.49(2)°, V = 8485 Å 3, D c = 1.27 g · cm −3 and Z = 8. The crystal structure was refined to a conventional R( F) = 0.0584 and R w ( F) = 0.0653 for 5132 unique reflections with F 0 > 3σ( F 0). The iron atom is pentacoordinated by the four nitrogen atoms and one oxygen atom of the acetate group. It lies at 0.520(1) Å out of the porphinato plane and 0.485(1) Å out of the four nitrogen plane. The FeO bond length is 1.898(4) Å.