Seven-coordinate tetraoxolate complexes. (8th January 2018)

• Record Type: Journal Article
• Authors: Simonson, Andrew N.; Kareis, Christopher M.; Ovanesyan, Nikolaii S.; Baumann, David O.; Rheingold, Arnold L.; Arif, Atta M.; Miller, Joel S.
• Is Part Of: Polyhedron. Volume 139(2018)
• Page Start: 215
• Page End: 221
• Publication Date: 2018-01-08
• Subjects: Antiferromagnetic interaction -- Tetraoxolate -- Mn complex -- μ-Oxo-diiron complex -- Mössbauer; Chemistry, Inorganic -- Periodicals; Chimie inorganique -- Périodiques; Organometaalverbindingen; Anorganische chemie; 546.05
• DOI: 10.1016/j.poly.2017.10.016
• Languages: English
• ISSNs: 0277-5387

Abstract

Graphical abstract: Seven coordinate [Fe III (TPyA)1NO2 ]2 O and Mn II (TPyA)1Cl [TPypA = (tris(2-pyridylmethyl)amine); Na2 1NO2 = sodium nitraniIate; H2 1Cl = chloranilic acid] have been structurally and magnetically characterized. The former is a dinuclear Fe III compound, and the latter forms a 1-D zigzag chain based upon the two bridging1NO2 2− ions. Abstract: The reaction of TPypA (tris(2-pyridylmethyl)amine) and Fe(BF4 )2 and sodium nitraniIate (Na2 1NO2 ) or Mn(O2 CMe)2 with chloranilic acid (H2 1Cl ) respectively forms [Fe III (TPyA)1NO2 ]2 O and Mn II (TPyA)1Cl, respectively. The structures of these 7-coordinate compounds have been determined. The former is a dinuclear Fe III compound possessing equivalent Fe(III) sites, and the latter forms a 1-D zigzag chain based upon the two bridging1NO2 2− ions. The isomer shift and quadrupole splitting of the 57 Fe Mössbauer spectra of [Fe(TPyA)1NO2 ]2 O are consistent binuclear seven-coordinate high-spin Fe III state. Below 35 K a single quadrupole doublet split onto two doublets of equal intensities and equal isomer shifts as a result of structural non-equivalency of two iron sites within a dimer. The magnetic properties of [Fe III (TPyA)1NO2 ]2 O can be fit the a homonuclear S = 5/2 ± 5/2 dinuclear spin model with strong intradimer antiferromagnetic coupling of J / k B = −146 K (−101 cm −1 ) and g = 2.00, and interdimer coupling of θ = −5 K ( H = −2 J Sa ·Sb ). Mn II (TPyA)1Cl can be fit the a homonuclear S = 5/2 1-D Fisher chain expression with weak intrachain antiferromagnetic coupling with J / k B = −0.33 K (−0.23 cm −1 ) and g = 2.06.