Biomimetic Oxidation Studies. 8. Structure of a New MMO Active Site Model, [Fe2O(H2O)2(tris((1-methylimidazol-2-yl)methyl)amine)2]4+,and Role of the Aqua Ligand in Alkane Functionalization Reactions

Abstract

2) Other representative studies on metal complex/TBHP systems are as follows, respectively: (a)

Low‐Molecular‐Weight Analogues of the Soluble Methane Monooxygenase (sMMO): From the Structural Mimicking of Resting States and Intermediates to Functional Models

“…[47] Until the end of the 1990s further similar oxygenation reactions were published (Table 1), but presumably in most cases Gif-related species [49,50] were responsible for the highly efficient oxidation of methylene units present in the hydrocarbons employed. The same could be true for the oxidation of cyclohexane with tert-butyl hydroperoxide or hydrogen peroxide reported to occur in the presence of compounds with the general formula [L n Fe 2 A C H T U N G T R E N N U N G (m-O)] as catalysts: [51,52,55] Mechanistic studies did not reveal any hints or spectroscopic evidence for the involvement of high-valent oxidodiiron species. On the contrary, more detailed inquiries indicated the participation of radicals and/or high-valent, mononuclear species.…”

Single-crystal absorption spectroscopy of binuclear complexes of iron(III) and manganese(III) with the μ-oxo-bis(μ-acetato)dimetal core

“…[2] and [ 3 ] originating from ground state levels with pair spin S as a function of temperature. The symbols denote experimental intensities determined from the absorption spectra in Fig.…”

“…The solid lines are fits to eqs. [2] and [3] for the transitions originating from the ground state levels with pair spins S of 0 and 1, respectively, with a value of -295 cm-' for the exchange coupling parameter J in eq.…”

“…4 relative intensities for the two most intense transitions, calculated from eqs. [2] and [3] with the literature value of -207 cm-' for the coupling constant J and by refining the constants Co and C,. This comparison shows that the intensities obtained with both values are reasonable, especially for the band originating from the level with a pair spin S of 1.…”

“…Binuclear complexes of iron and manganese with 0x0 and carboxylato bridging ligands are important constituents of the active sites in metalloproteins and have been shown to be catalytically active (1)(2)(3)(4)(5)(6). A large number of model compounds have been synthesized recently, among them a series of triply bridged binuclear compounds with the y-0x0-bis(y-acetato) bridging geometry (5,7).…”