Structures and properties of di-μ-oxo dimanganese(IV) complexes with bidentate Schiff bases, N-alkyl-substituted-salicylideneamine

Torayama, Hitoshi; Asada, Hideyuki; Fujiwara, Manabu; Matsushita, Takayuki

doi:10.1016/s0277-5387(98)00144-2

Cited by 22 publications

(5 citation statements)

References 8 publications

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“…However, Table 4. Calculated Exchange Coupling Constants J (cm -1 ) for Five Manganese Dinuclear Complexes, [40][41][42][43][44] a The Siesta code was used with PBE functional and basis sets of different quality and two different pseudopotentials. The Gaussian calculations were carried out with the PBE and B3LYP functionals using the double-ζ basis set (DZ) of Schaefer et al 33 for the main group elements and the triple-ζ one from the same authors for the manganese atoms (TZP).…”

Section: Computational Detailsmentioning

confidence: 99%

Magnetic Structure of the Large-Spin Mn₁₀ and Mn₁₉ Complexes: A Theoretical Complement to an Experimental Milestone

et al. 2008

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High-spin molecules have been proposed as candidates for the storage of information at the molecular level. The electronic structure of two complex magnetic molecular systems, Mn 10 and Mn 19, is characterized by means of a computational study based on density functional theory. All the exchange interactions in the recently reported Mn 19 complex with the highest known spin value of 83/2, and in its highly symmetric Mn 10 parent compound, are ferromagnetic. In these complexes, there are two kinds of ferromagnetic coupling: the first one corresponds to Mn (II)-Mn (III) interactions through a double mu 2-alkoxo-mu 4-oxo bridge where the high coordination number of the Mn (II) cations results in long Mn (II)-O bond distances, while the second one involves Mn (III)-Mn (III) interactions through mu 2-alkoxo-mu 3-eta (1):eta (1):eta (1) azido bridging ligands with long Mn (III)-N distances due to a Jahn-Teller effect.

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Section: Computational Detailsmentioning

confidence: 99%

Magnetic Structure of the Large-Spin Mn₁₀ and Mn₁₉ Complexes: A Theoretical Complement to an Experimental Milestone

et al. 2008

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“…The TIP magnitudes obtained here are unexpectedly large. However, such values are not unprecedented and have been observed for other d 3 −d 3 dimers including the Mn(IV) 15 and Cr(III) systems. 49a HF-EPR Studies, General Comments.…”

Section: ■ Results and Discussionmentioning

confidence: 87%

“…With few exceptions most of these examples are limited to oxo-bridged dimers, 13 such as [L 2 Mn 2 (μ-O)μ-phBO 2 ) 2 ](PF 6 ) 2 (L = 1,4,7-trimethyl-1,4,7-triazacyclononane, phBO 2 = phenyl boronic acid). 14,15 Interestingly, a strong dependence of the metal−metal interaction strength on the protonation of the oxo-bridges was reported. 13c Although these metals sites are usually probed using X-band EPR spectroscopy, the dimeric molecules exhibit relatively large zero-field splitting in their spin-triplet state requiring application of the HF EPR measurements.…”

Section: ■ Introductionmentioning

confidence: 99%

Model Dimeric Manganese(IV) Complexes Featuring Terminal Tris-hydroxotetraazaadamantane and Various Bridging Ligands

et al. 2020

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A series of model dinuclear manganese(IV) complexes of the general formula [(H 3 COH)(L′)Mn IV (μ-L) 2 Mn IV (L′)(HOCH 3 )] is presented. These compounds feature capping 4,6,10-trihydroxo-3,5,7-trimethyl-1,4,6,10-tetraazaadamantane ligands derived from a polydentate oxime compound (L′). The bridging ligands L include azide (1), methoxide (2), and oxalate (3) anions. The magnetic properties and high-field (HF) EPR spectra of 1−3 were studied in detail and revealed varying weak antiferromagnetic coupling and modest zero-field splitting (ZFS) of the local quartet spin sites. Our HF EPR studies provide insight into the dimer ZFS, including determination of the corresponding parameters by giant spin approach for methoxido-bridged complex 2. Furthermore, the physicochemical properties of 1−3 were studied using IR, UV−vis, and electrochemical (cyclic voltammetry) methods. Theoretical exchange coupling constants were obtained using broken-symmetry (BS) density functional theory (DFT). Computational estimates of the local quartet ground spins state ZFSs of 1−3 were obtained using coupled-perturbed (CP) DFT and complete active space self-consistent field (CASSCF) calculations with n-electron valence state perturbation theory (NEVPT2) corrections. We found that the CP DFT calculations which used the B3LYP functional and models derived experimental structures performed best in reproducing both the magnitude and the sign of the experimental D values. Moreover, our computational investigation of 1−3 suggests that we observe metals sites which have an increased +3 character and are supported by redox noninnocent 4,6,10-trihydroxo-3,5,7-trimethyl-1,4,6,10-tetraazaadamantane ligands. The latter conclusion is further corroborated by the observation that the free ligand can be readily oxidized to yield a NO-based radical.

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“…The J value for 1 indicates strong intramolecular antiferromagnetic interaction between the two Mn IV ions, and falls in the range of corresponding values of such [Mn IV 2 O 2 ] 4+ species. 29 In the previous papers, studies on the magneto-structural relations of binuclear [Mn IV Mn III O 2 ] 3+ and [Mn III Mn III O 2 ] 2+ have been intensively investigated. However in the case of the [Mn IV 2 O 2 ] 4+ complex, the correlation is comparatively poor.…”

Section: Magnetic Measurementmentioning

confidence: 99%

Efficient single-strand cleavage of DNA mediated by a Mn^IIIMn^IV-based artificial nuclease

Qian

Wang

et al. 2014

Dalton Trans.

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A water-soluble Mn(IV) 1,4,7-triazacyclononane complex, [Mn(IV)2L2(μ-O)2](ClO4)2·2H2O (1), was prepared to serve as a nuclease mimic (L = 1,4,7-triazacyclononane-N-acetate). Complex 1 was readily synthesized from the highly water soluble ligand (L), with Mn(III) salt, [Mn3O(MeCO2)7]·3H2O in basic condition, and characterized by X-ray, IR, electronic spectroscopy, cyclic voltammetry and magnetic susceptibility as well as ESI-MS. The bond valence sum (BVS) analysis and magnetic data suggest that 1 is a Mn(IV)-μ-O2-Mn(IV) species. The electrospray mass spectrum and electronic spectrum of 1 in aqueous solution indicates that dinuclear Mn complex [Mn(III)Mn(IV)L2(μ-O)2](+) (2) is the active species. A predominantly hydrolytic cleavage mechanism was confirmed through experiments performed in the presence of various radical scavengers, T4 ligase and under anaerobic conditions. The kinetic aspects of DNA cleavage under pseudo- or true-Michaelis-Menten conditions were also detailed, kinetic parameters (kcat, KM, Vmax) were calculated to be 6.27 h(-1), 7.35 × 10(-5) M, 4.6 × 10(-4) M h(-1); 0.683 h(-1), 1.93 × 10(-5) M, 1.32 × 10(-5) M h(-1) for 2, respectively.

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Structures and properties of di-μ-oxo dimanganese(IV) complexes with bidentate Schiff bases, N-alkyl-substituted-salicylideneamine

Cited by 22 publications

References 8 publications

Magnetic Structure of the Large-Spin Mn₁₀ and Mn₁₉ Complexes: A Theoretical Complement to an Experimental Milestone

Magnetic Structure of the Large-Spin Mn₁₀ and Mn₁₉ Complexes: A Theoretical Complement to an Experimental Milestone

Model Dimeric Manganese(IV) Complexes Featuring Terminal Tris-hydroxotetraazaadamantane and Various Bridging Ligands

Efficient single-strand cleavage of DNA mediated by a Mn^IIIMn^IV-based artificial nuclease

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Structures and properties of di-μ-oxo dimanganese(IV) complexes with bidentate Schiff bases, N-alkyl-substituted-salicylideneamine

Cited by 22 publications

References 8 publications

Magnetic Structure of the Large-Spin Mn10 and Mn19 Complexes: A Theoretical Complement to an Experimental Milestone

Magnetic Structure of the Large-Spin Mn10 and Mn19 Complexes: A Theoretical Complement to an Experimental Milestone

Model Dimeric Manganese(IV) Complexes Featuring Terminal Tris-hydroxotetraazaadamantane and Various Bridging Ligands

Efficient single-strand cleavage of DNA mediated by a MnIIIMnIV-based artificial nuclease

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Magnetic Structure of the Large-Spin Mn₁₀ and Mn₁₉ Complexes: A Theoretical Complement to an Experimental Milestone

Magnetic Structure of the Large-Spin Mn₁₀ and Mn₁₉ Complexes: A Theoretical Complement to an Experimental Milestone

Efficient single-strand cleavage of DNA mediated by a Mn^IIIMn^IV-based artificial nuclease