Chelate‐Thiolate‐Coordinate Ligands Modulating the Configuration and Electrochemical Property of Dinitrosyliron Complexes (DNICs). Issue 45 (25th September 2015)

• Record Type: Journal Article
• Authors: Yeh, Shih‐Wey; Lin, Chih‐Wei; Liu, Bai‐Heng; Tsou, Chih‐Chin; Tsai, Ming‐Li; Liaw, Wen‐Feng
• Is Part Of: Chemistry. Volume 21:Issue 45(2015)
• Page Start: 16035
• Page End: 16046
• Publication Date: 2015-09-25
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201502071
• Languages: English
• ISSNs: 0947-6539

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>As opposed to the reversible redox reaction ({Fe(NO)<sub>2</sub>}<sup>10</sup> reduced‐form DNIC [(NO)<sub>2</sub>Fe(S(CH<sub>2</sub>)<sub>3</sub>S)]<sup>2−</sup> (<bold>1</bold>)⇌{Fe(NO)<sub>2</sub>}<sup>9</sup> oxidized‐form [(NO)<sub>2</sub>Fe(S(CH<sub>2</sub>)<sub>3</sub>S)]<sup>−</sup>), the chemical oxidation of the {Fe(NO)<sub>2</sub>}<sup>10</sup> DNIC [(NO)<sub>2</sub>Fe(S(CH<sub>2</sub>)<sub>2</sub>S)]<sup>2−</sup> (<bold>2</bold>) generates the dinuclear {Fe(NO)<sub>2</sub>}<sup>9</sup>–{Fe(NO)<sub>2</sub>}<sup>9</sup> complex [(NO)<sub>2</sub>Fe(μ‐SC<sub>2</sub>H<sub>4</sub>S)<sub>2</sub>Fe(NO)<sub>2</sub>]<sup>2−</sup> (<bold>3</bold>) bridged by two terminal [SC<sub>2</sub>H<sub>4</sub>S]<sup>2−</sup> ligands. On the basis of the Fe K‐edge pre‐edge energy and S K‐edge XAS, the oxidation of complex <bold>1</bold> yielding [(NO)<sub>2</sub>Fe(S(CH<sub>2</sub>)<sub>3</sub>S)]<sup>−</sup> is predominantly a metal‐based oxidation. The smaller S1‐Fe1‐S2 bond angle of 94.1(1)° observed in complex <bold>1</bold> (S1‐Fe1‐S2 88.6(1)° in complex <bold>2</bold>), compared to the bigger bond angle of 100.9(1)° in the {Fe(NO)<sub>2</sub>}<sup>9</sup> DNIC [(NO)<sub>2</sub>Fe(S(CH<sub>2</sub>)<sub>3</sub>S)]<sup>−</sup>, may be ascribed to the electron‐rich {Fe(NO)<sub>2</sub>}<sup>10</sup> DNIC preferring a restricted bite angle to alleviate the electronic donation of the chelating thiolate to the electron‐rich {Fe(NO)<sub>2</sub>}<sup>10</sup> core. The extended transition state and natural orbitals for chemical valence (ETS‐NOCV) analysis on the edt‐/pdt‐chelated {Fe(NO)<sub>2</sub>}<sup>9</sup> and {Fe(NO)<sub>2</sub>}<sup>10</sup> DNICs demonstrates how two key bonding interactions, that is, a FeS covalent σ bond and thiolate to the Fe d<inline-formula><alternatives><inline-graphic mimetype="image" xlink:href="ark:/27927/pgkwbw5t1s" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /><mml:math altimg="urn:x-wiley:09476539:media:CHEM201502071:tex2gif-inf-33" overflow="scroll" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mtext> </mml:mtext><mml:mrow><mml:mtext fontstyle="italic">z</mml:mtext><mml:msup><mml:mtext> </mml:mtext><mml:mrow><mml:mtext>2</mml:mtext></mml:mrow></mml:msup></mml:mrow></mml:msub></mml:math></alternatives></inline-formula> charge donation, between the chelating thiolate ligand and the {Fe(NO)<sub>2</sub>}<sup>9/10</sup> core could be modulated by the backbone lengths of the chelating thiolate ligands to tune the electrochemical redox potential (<italic>E</italic><sub>1/2</sub>=−1.64 V for complex <bold>1</bold> and <italic>E</italic><sub>1/2</sub>=−1.33 V for complex <bold>2</bold>) and to dictate structural rearrangement/chemical transformations (S‐Fe‐S bite angle and monomeric vs. dimeric DNICs).</p> </abstract>