Linear, Planar, Orbicular, and Macrocyclic Multinuclear Zinc (Meth)acrylate Complexes

• Published in: Chemistry : a European journal 2024-06, Vol.30 (33), p.e202400586-n/a
• Main Authors: Iwasaki, Takanori, Suehisa, Gaito, Tadaoka, Hiroshi, Shiga, Kazuyoshi, Nozaki, Kyoko
• Format: Article
• Language: English
• Subjects: (meth)acrylate; Crystallization; crystallography; Ligands; macrocycle; Molecular chains; molecular packing; Molecular structure; Structural analysis; Zinc; zinc carboxylate
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.202400586

Zinc carboxylate complexes are widely utilized as artificial models of metalloenzymes and as secondary building units of PCPs/MOFs. However, the relationship between the structure of the monodentate carboxylato ligand and the molecular arrangement of multinuclear zinc carboxylate complexes is not fully understood because of the coordination flexibility of the Zn ion and carboxylato ligands. Herein, we report the structural analysis of a series of complexes derived from zinc (meth)acrylate which has a linear infinite chain structure. The molecular structure of μ4‐oxido‐bridged tetranuclear complexes [Zn4(μ4‐O)(OCOR)6] revealed a distorted Zn4O core. Crystallization of zinc acrylate under aqueous conditions afforded a μ3‐hydroxido‐containing pentanuclear complex [Zn5(μ3‐OH)2(OCOR)8] as the repeating unit of an infinite sheet‐like structure in the solid state. It was also obtained by the hydrolysis of the μ4‐oxido‐bridged tetranuclear complex. In sharp contrast, the methacrylate analog retained the methacrylato ligands under aqueous crystallization conditions to form a macrocyclic dodecanuclear complex with methacrylato as the sole ligand. The diverse structures of zinc (meth)acrylate are present herein. The linear polymeric structure consisting of dinuclear repeating units of zinc (meth)acrylate is converted to a Zn4 cluster upon treating with ZnO. Recrystallization of zinc acrylate from a hydrous solvent affords a sheet‐like structure consisting of Zn5 repeating units bridged by two μ3‐OH, whereas zinc methacrylate affords a cyclic Zn12 structure supported by methacrylato ligands.