Syntheses, Structures, and Properties of Coordination Polymers with 2,5-Dihydroxy-1,4-Benzoquinone and 4,4'-Bipyridyl Synthesized by In Situ Hydrolysis Method

Daiki Yamazui; Kaiji Uchida; Shohei Koyama; Bin Wu; Hiroaki Iguchi; Wataru Kosaka; Hitoshi Miyasaka; Shinya Takaishi

doi:10.1021/acsomega.1c07077

Syntheses, Structures, and Properties of Coordination Polymers with 2,5-Dihydroxy-1,4-Benzoquinone and 4,4'-Bipyridyl Synthesized by In Situ Hydrolysis Method

ACS Omega. 2022 May 24;7(22):18259-18266. doi: 10.1021/acsomega.1c07077. eCollection 2022 Jun 7.

Authors

Daiki Yamazui¹, Kaiji Uchida¹, Shohei Koyama¹, Bin Wu¹, Hiroaki Iguchi¹, Wataru Kosaka², Hitoshi Miyasaka², Shinya Takaishi¹

Affiliations

¹ Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aramaki-Aza-Aoba, Aoba-ku, Sendai, Miyagi 980-8578, Japan.
² Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan.

Abstract

The coordination polymers (CPs) with binary ligands, including 2,5-dihydroxy-1,4-benzoquinone (H2DHBQ) and 4,4'-bipyridyl (bpy), were synthesized using in situ hydrolysis of 2,5-dimethoxy-1,4-benzoquinone (DMBQ). Three kinds of CPs were obtained depending on the metal ions. For M = Mn and Zn, a 1D zigzag chain structure with cis conformation ( cis-1D-M) was obtained, whereas Co, Ni, and Cu compounds afforded a 2D net structure with trans conformation (trans -2D-M) with a 1D pore. A linear chain structure was also obtained for M = Cu. Magnetic susceptibility (χ_M T) at 300 K in cis -1D-Mn and trans -2D-Co was evaluated to be 4.421 and 2.950 cm³ K mol^-1, respectively, indicating that both compounds are in the high-spin state. According to the N₂ adsorption isotherms at 77 K, trans -2D-Ni showed microporosity with the BET surface area of 177 m² g^-1, whereas the isomorphic trans -2D-Co rarely adsorbed N₂ at 77 K. This phenomenon was explained by the difference of diffusion kinetics of the adsorbent molecules, which was supported by the CO₂ adsorption isotherms at 195 K. The optical band gaps of cis -1D-Mn, cis -1D-Zn, trans -2D-Co, and trans -2D-Ni were estimated to be 1.6, 1.8, 1.0, and 1.1 eV, respectively, by using UV-vis-NIR spectroscopy.