Structure and electrochemical properties of (μ-O)Mn(,) and (μ-O)Mn(,) complexes supported by pyridine-, quinoline-, isoquinoline- and quinoxaline-based tetranitrogen ligands

• Published in: Dalton transactions : an international journal of inorganic chemistry 2021-03, Vol.5 (12), p.4133-4144
• Main Authors: Mikata, Yuji, Kuroda, Yasuko, Naito, Kyoko, Murakami, Kana, Yamamoto, Chihiro, Yabe, Shoko, Yonemura, Shizuka, Matsumoto, Arimasa, Katano, Hajime
• Format: Article
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/d1dt00184a

Seven new bis(μ-oxo)dimanganese complexes with Mn 2 ( iii , iii ) or Mn 2 ( iii , iv ) oxidation states were prepared using quinoline- and isoquinoline-based tetraamine ligands. The structures of the ligands include ethylenediamine, trans -1,2-cyclohexanediamine and tripodal amine, bearing two or three nitrogen-containing heteroaromatics. Regardless of the skeleton and number of aliphatic nitrogen atoms in the ligands, quinoline complexes stabilize the Mn 2 ( iii , iii ) oxidation state, whereas, isoquinoline ligands afford Mn 2 ( iii , iv ) complexes. A systematic comparison of the differences in structural parameters and redox potentials of a total of 14 complexes with a (μ-O) 2 Mn 2 diamond core, which includes corresponding pyridine and quinoxaline derivatives as supporting ligands, highlights the distinct deviation of quinoline and tripodal amine motifs in this ligand series. A systematic comparison of a total of 14 complexes bearing a (μ-O) 2 Mn 2 core with tetranitrogen ligands reveals small but solid relationships between structural parameters and redox potentials induced by ligand effects.