Abstract
The global demand for energy and the concerns over climate issues renders the development of alternative renewable energy sources such as hydrogen (H2) important. A high-spin (hs) FeII complex with o-phenylenediamine (opda) ligands, [FeII(opda)3]2+ (hs-[6R]2+), was reported showing photochemical H2 evolution. In addition, a low-spin (ls) [FeII(bqdi)3]2+ (bqdi: o-benzoquinodiimine) (ls-[0R]2+) formation by O2 oxidation of hs-[6R]2+, accompanied by ligand-based six-proton and six-electron transfer, revealed the potential of the complex with redox-active ligands as a novel multiple-proton and -electron storage material, albeit that the mechanism has not yet been understood. This paper reports that the oxidized ls-[0R][PF6]2 can be reduced by hydrazine giving ls-[FeII(opda)(bqdi)2][PF6]2 (ls-[2R][PF6]2) and ls-[FeII(opda)2(bqdi)][PF6]2 (ls-[4R][PF6]2) with localized ligand-based proton-coupled mixed-valence (LPMV) states. The first isolation and characterization of the key intermediates with LPMV states offer unprecedented molecular insights into the design of photoresponsive molecule-based hydrogen-storage materials.
Original language | English |
---|---|
Pages (from-to) | 9609-9619 |
Number of pages | 11 |
Journal | Chemistry - A European Journal |
Volume | 26 |
Issue number | 43 |
DOIs | |
Publication status | Published - 2020 Aug 3 |
Externally published | Yes |
Keywords
- N ligands
- iron
- oxidation
- reduction
- valency
ASJC Scopus subject areas
- Catalysis
- Organic Chemistry