ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Mixed-valent tetranuclear manganese complexes with pentadentate Schiff-base ligand having a Y-shaped core

Masahiro Mikuriya, Sayuri Kudo, Chisa Matsumoto, Satoshi Kurahashi, Seiki Tomohara, Yoshiki Koyama, Daisuke Yoshioka, and Ryoji Mitsuhashi

Kwansei Gakuin University, Sanda, Japan

E-mail: junpei@kwansei.ac.jp

Abstract: Reaction of pentadentate Schiff-base ligands, 1,3-bis(3-methoxysalicylideneamino)-2-propanol (H₃msap) with manganese(II) salts afforded tetranuclear mixed-valent manganese complexes, [Mn₄(msap)₂(CH₃CO₂)₃(CH₃O)(H₂O)]·H₂O (1) and [Mn₄(msap)₂(C₆H₅CO₂)₃(CH₃O)] (2), which were characterized by elemental analysis, infrared and diffused reflectance spectra and temperature dependence of magnetic susceptibilities (4.5–300 K). Single-crystal X-ray crystallography of these complexes showed that four manganese atoms are chelated by two Schiff-base ligands and further coordinated by syn–syn bridging, syn–anti bridging, and monodentate or bidentate-carboxylato groups, forming a Y-shaped cluster made up of two Mn^II and two Mn^III atoms. Diffused reflectance spectra are featureless, showing broad bands around at near-UV and visible regions. Magnetic moments decrease with lowering of temperature, showing an antiferromagnetic behavior of these complexes.

Keywords: Manganese complex ; Mixed-valent complex ; Tetranuclear complex ; Schiff-base ligand 

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-017-0305-6

Chemical Papers 72 (4) 853–862 (2018)