Synthesis, Structure and Property of Oxo-Bridged Binuclear Iron(III) Complex [Fe(phen)(H2O)3]2O?2SO4

Abstract

An oxo-bridged binuclear iron(III) complex, [Fe(phen)(H 2 O) 3 ] 2 O·2SO 4 , has been synthesized and structurally characterized by elemental analysis (EA), IR, TG-DSC and X-ray. Its crystal structure has been determined by X-ray crystallography. It crystallizes in the orthorhombic system, space group P2 1 2 1 2, with lattice parameters a = 17.650(4), b = 8.5133 (17), c = 9.971(2)Å; V = 1498.2(5)Å 3 , ρ calcd = 1.763 g/cm 3 and Z = 4 for R 1 = 0.0601. The crystal structure indicated that two octahedrally coordinated iron(III) ions bridged with oxygen atoms formed a non-linear complex. The bond angle of Fe-O-Fe is 163.9(4) • . The data of EA and IR are in good agreement with the crystal structure. The thermal gravity (TG) data indicate that there are four decomposition steps with three endothermic peaks. The final product of the thermal decomposition may be Fe(C 2 H 8 N 2 )SO 4 .

Experimental and Theoretical Investigation of Intercalation and Molecular Structure of Organo-Iron Complexes in Montmorillonite

“…Adsorption of Different Conformers of FePhen onto Montmorillonite. Two crystal polymorphs of the sulfate salt of FePhen have been reported: PhenFeS1 9 and PhenFeS2, 25 and the structure of PhenFeS2 has been recently refined. 8 The main difference between these polymorphs is the molecular structure of the conformers of the FePhen complex.…”

Crystal chemical characterization and computational modeling of a μ-oxo Fe(III) complex with 1,10-phenanthroline clarify its interaction and reactivity with montmorillonite

“…Unlike what found for others oxo-bridged binuclear iron(III) complex already reported in literature (e.g., Jian et al 2005) our crystals were synthesized without any energy supply. A 6 mM phenanthroline solution was prepared by dissolving phenanthroline in 10 mM acetate aqueous buffer at pH 5; Fe 2 (SO 4 ) 3 Á8H 2 O salt was then slowly dissolved at room temperature in the phenanthroline solution in order to have a Fe(III)/phenanthroline ratio equal to one.…”

“…A semi-empirical absorption correction was applied using the SADABS program (Bruker 2012). Crystal structure refinement was initially performed in the orthorhombic space group P2 1 2 1 2 following previous literature data (Jian et al 2005). Final refinement was not, however, fully satisfactory as all C atoms appear split in two positions.…”

“…The feature of the l-oxo-bridge (a weak oxygen ligand to both irons) which mimics the structure of some iron proteins such as hemerythrin and ribonucleotide reductase could enhance the reactivity of the iron and its performance as a catalyst with respect to the already active cytochrome c (Castellini et al 2013;Ranieri et al 2011Ranieri et al , 2012. Structural reports of different l-oxo-bridged Fe complexes with 1,10 phenanthroline include the structure of: (1) the (l-oxo)bis[aquobis (phenanthroline)iron(III)] complex characterized by two ferric iron atoms bridged by a single oxo ligand (Plowman et al 1984); (2) an oxo-bridged Fe complex of 1,10 phenanthroline, the l-oxo-j 2 O:O-bis[bis(1,10phenanthroline-j 2 N,N 0 )(sulfato-jO)iron(III)] octahydrate, with two phenanthroline rings per each Fe cation, where one sulfate group is a monoligand of each Fe(III) (Odoko and Okabe 2005); (3) a complex in which iron and phenanthroline are in 1:1 molar ratio, the l-oxo-bisfac-[triaqua-1,10-phenanthroline-iron(III)]-tetrakis (nitrate) monohydrate, characterized by two symmetrically independent Fe(III) cations chelated by the N atoms of phenanthroline bridged by an oxygen atom (Healy et al 1984); (4) the l-oxo-di-l-sulfato-bis [aqua (1,10phenanthroline-j 2 N,N 0 ) iron (III)]tetrahydrate, where the octahedral coordination sphere of each Fe(III) is completed by the oxo-bridge, two phenanthroline N atoms, two O atoms of each different sulfate group, and one water molecule; the sulfate groups bridge the two octahedral Fe(III), whereas adjacent crystallization water molecules are linked through hydrogen bonds into a three-dimensional network (Zhao et al 2006); (5) the orthorhombic (space group P2 1 2 1 2) [(OH 2 ) 3 (Phen) FeO Fe(Phen) (OH 2 ) 3 ] (SO 4 ) 2 (Phen = 1,10-phenanthroline) (Jian et al 2005), with a coordination sphere of Fe(III) similar to that of the nitrate salt reported by Healy et al (1984), where the phenanthroline rings are coplanar.…”

Interplay of thermochemistry and Structural Chemistry, the journal (volume 16, 2005) and the discipline

“…Next, Jian et al [52] report on the synthesis of the oxobridged binuclear iron(III) complex [Fe(phen)(H 2 O) 3 ] 2 OÁ 2SO 4 . They used elemental analysis, infrared spectroscopy, and thermal gravimetric-differential scanning calorimetry to structurally characterize the complex.…”