Chasing the Evasive Fe═O Stretch and the Spin State of the Iron(IV)–Oxo Complexes by Photodissociation Spectroscopy

Erik Andris†, Rafael Navrátil†, Juraj Jašík†, Thibault Terencio†, Martin Srnec*§ , Miquel Costas*‡ , and Jana Roithová*†

† Department of Organic Chemistry, Faculty of Science, Charles University, Hlavova 2030/8, 12843 Prague 2, Czech Republic

‡ Departament de Quimica and Institute of Computational Chemistry and Catalysis (IQCC), University of Girona, Campus Montilivi, Girona 17071, Spain

§ J. Heyrovsky Institute of Physical Chemistry of the CAS, v.v i., Dolejškova 2155/3, 182 23 Prague 8, Czech Republic

J. Am. Chem. Soc., 2017, 139 (7), pp 2757–2765

DOI: 10.1021/jacs.6b12291

Publication Date (Web): January 26, 2017

[質問]
ガス状へとイオン化された鉄錯体は気相中で基質とどのように反応させているか

[回答]

まず、鉄錯体はESIによってイオン化されIon soureceへと移ります。Quadrupole (4P1)では質量によって分離が行われ、Quadrupole bender (QPD)、Octopole (8P)を経て、Wire quadrupole ion trap (w4PT)に到達します。このイオントラップには3 K、0.3 mTorr以下のコンディションで、かつヘリウムガスが充填されています。ここで錯体とヘリウムが複合体を形成し、照射されたIRに応じて乖離が起こり、最終的にQuadrupole (4P2)で検出、分析が行われます。
この途中で通過するOctopole (8P)において、test tubeからガス状の基質が入り、反応を行っています。このOctopole (8P)のコンディションについては、温度は室温であり、入れる基質の量は流速によってコントロールしています。
ここで反応した鉄錯体の分解物がイオントラップでヘリウムとの複合体を形成し、Quadrupole (4P2)でのMSを測定することで鉄錯体の分解物を同定し、その分解物から基質とどのような反応が起こったかを決定しました。

Electrochemical evidence that pyranopterin redox chemistry controls the catalysis of YedY, a mononuclear Mo enzyme

Hope Adamson a, Alexandr N. Simonov b, Michelina Kierzek c, Richard A. Rothery c, Joel H. Weiner c, Alan M. Bond b, and Alison Parkin a,1 a Department of Chemistry, University of York, Heslington, York YO10 5DD, United Kingdom; b School of Chemistry, Monash University, Clayton, VIC 3800, Australia; and c Department of Biochemistry, University of Alberta, Edmonton, AB T6G 2H7, Canada Edited by Harry B. Gray, California Institute of Technology, Pasadena, CA, and approved October 13, 2015 (received for review August 25, 2015) http://www.pnas.org/content/112/47/14506.short A long-standing contradiction in the field of mononuclear Mo enzyme research is that small-molecule chemistry on active-site mimic compounds predicts ligand participation in the electron transfer reactions, but biochemical measurements only suggest metal-centered catalytic electron transfer.With the simultaneous measurement of substrate turnover and reversible electron transfer that is provided by Fourier-...

Rhenium(V)–oxo corrolazines: isolating redox-active ligand reactivity

Jan Paulo T. Zaragoza,a Maxime A. Sieglera and David P. Goldberg* Chem. Commun., 2015, Advance Article DOI: 10.1039/C5CC07956J Received 22 Sep 2015, Accepted 15 Oct 2015 First published online 28 Oct 2015 http://pubs.rsc.org/en/content/articlelanding/2015/cc/c5cc07956j#!divAbstract Abstract The synthesis of the first example of a third-row metallocorrolazine characterized by single crystal X-ray diffraction is reported. This ReV(O) porphyrinoid complex shows an exclusively ligand-based reactivity with strong acids and oxidizing agents. The one-electron oxidized π-radical-cation complex is capable of H-atom abstraction.

Tuning Reactivity and Selectivity in Hydrogen Atom Transfer from Aliphatic C–H Bonds to Alkoxyl Radicals: Role of Structural and Medium Effects

Michela Salamone and Massimo Bietti* Dipartimento di Scienze e Tecnologie Chimiche, Università “Tor Vergata”, Via della Ricerca Scientifica, Italy Acc. Chem. Res., Article ASAP DOI: 10.1021/acs.accounts.5b00348 Publication Date (Web): November 6, 2015 クメンパーオキシドを光で開裂させることにより、生成するクミルアルコキシルラジカルによるアルカンやアミンのC–H切断の速度定数などの情報がまとまっています。溶媒や、酸、基質の形が反応速度定数に与える影響を定量的に評価しています。酸化反応をしている方は、手元に置いておいても良いのでしょうか。

C–H Bond Oxidation Catalyzed by an Imine-Based Iron Complex: A Mechanistic Insight

Giorgio Olivo§¶, Martina Nardi§, Diego Vìdal¶, Alessia Barbieri§, Andrea Lapi§‡, Laura Gómez¶⊥, Osvaldo Lanzalunga§‡, Miquel Costas*¶, and Stefano Di Stefano*§‡ § Università degli Studi di Roma, Rome, Italy ¶ Institut de Química Computacional i Catàlisi (IQCC), Girona, Spain Inorg. Chem., 2015, 54 (21), pp 10141–10152 DOI: 10.1021/acs.inorgchem.5b01500 Publication Date (Web): October 12, 2015 A family of imine-based nonheme iron(II) complexes (LX)2Fe(OTf)2 has been prepared, characterized, and employed as C–H oxidation catalysts. Ligands LX (X = 1, 2, 3, and 4) stand for tridentate imine ligands resulting from spontaneous condensation of 2-pycolyl-amine and 4-substituted-2-picolyl aldehydes. Fast and quantitative formation of the complex occurs just upon mixing aldehyde, amine, and Fe(OTf)2 in a 2:2:1 ratio in acetonitrile solution. The solid-state structures of (L1)2Fe(OTf)(ClO4) and (L3)2Fe(OTf)2 are reported, showing a low-spin octahedral iron center, with the lig...

Oxidative Alkene Cleavage Catalysed by Manganese-Dependent Cupin TM1459 from Thermotoga maritima

van Hajnal 1 , Kurt Faber 1,2 , Helmut Schwab 1,3 , Mélanie Hall 2,* and Kerstin Steiner 1,* a acib, Austrian Centre of Industrial Biotechnology GmbH, Petersgasse 14, 8010 Graz, Austria Fax: ( + 43)-316-873-9302; phone: ( + 43)-316-873-9346; e-mail: kerstin.steiner@acib.at b Department of Chemistry, University of Graz, Heinrichstraße 28, 8010 Graz, Austria Fax: ( + 43)-316-380-9840; phone: ( + 43)-316-380-5479; e-mail: melanie.hall@uni-graz.at c Institute of Molecular Biotechnology, TU Graz, Petersgasse 14, 8010 Graz, Austria Adv .S ynth. Catal. 2015 , 357 , 3 309 –3 316 DOI: 10.1002/adsc.201500608 Abstract A novel biocatalytic oxidative alkene cleavage activity was identified in protein TM1459 from Thermotoga maritima , a so far uncharacterised metalloprotein with a cupin fold, which preferentially binds manganese (over iron and zinc). Various styrene derivat...

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