Ultrastable Anti‐Acid “Shield” in Layered Silver Coordination Polymers

• Published in: Angewandte Chemie International Edition Vol. 61; no. 44; pp. e202209971 - n/a
• Main Authors: Sun, Peipei, Xie, Mo, Zhang, Lin‐Mei, Liu, Jia‐Xing, Wu, Jin, Li, Dong‐Sheng, Yuan, Shang‐Fu, Wu, Tao, Li, Dan
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 02.11.2022
• Edition: International ed. in English
• Subjects: 2D Coordination Polymers; Anti-Acid; Boiling; Buffer layers; Chemical compounds; Coordination polymers; Corrosion prevention; Corrosion resistance; Ethanol; Hydrogen peroxide; Hydrophobicity; Interfacial Structures; Metal Nanomaterials; Metal particles; Polymers; Silver; Sodium hydroxide; Stability analysis
• ISSN: 1433-7851; 1521-3773; 1521-3773
• DOI: 10.1002/anie.202209971

Surface passivation technology provides noble‐metal materials with limited chemical stability, especially under highly acidic condition. To design effective strategy to enhance stability of noble‐metal particles, an understanding of their surface anticorrosion mechanism at the atomic level is desirable by using two‐dimensional (2D) noble‐metal coordination polymer (CP) as an ideal model for their interfacial region. With the protection of 2‐thiobenzimidazole (TBI), we isolated two Ag‐based 2D CPs, {Ag14(TBI)12X2}n (S−X, where S denotes sheet and X=Cl or Br). These compounds exhibited excellent chemical stability upon immersion in various common solvents, boiling water, boiling ethanol, 10 % hydrogen peroxide, concentrated acid (12 M HCl), and concentrated alkali (19 M NaOH). Systematic characterization and DFT analyses demonstrate that the superior stability of S−X was attributed to the hydrophobic organic shell and dynamic proton buffer layer acting as a double protective “shield”. Acid resistance (12 M HCl) was made possible for two isomorphic two‐dimensional silver‐based coordination polymers. Protection is provided by a hydrophobic organic shell and a dynamic proton buffer layer via a thiolate‐thione tautomerism of 2‐thiobenzimidazole ligands. Thus, these ligands are promising surface inhibitors, acting as a dual protective shield against metal corrosion.