Mechanics of metal-catecholate complexes: The roles of coordination state and metal types

• Published in: Scientific reports Vol. 3; no. 1; p. 2914
• Main Author: Xu, Zhiping
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 10.10.2013; Nature Publishing Group
• Subjects: 639/301/1034/1035; 639/301/54/989; 639/301/923/1028; 639/638/298/303; Abrasion; Catechols - chemistry; Coordination Complexes - chemistry; Cross-Linking Reagents - metabolism; Humanities and Social Sciences; Mechanical properties; Mechanics; Metals; Metals - chemistry; Models, Molecular; Molecular Dynamics Simulation; multidisciplinary; pH effects; Science; Stress, Mechanical
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep02914

There have been growing evidences for the critical roles of metal-coordination complexes in defining structural and mechanical properties of unmineralized biological materials, including hardness, toughness and abrasion resistance. Their dynamic (e.g. pH-responsive, self-healable, reversible) properties inspire promising applications of synthetic materials following this concept. However, mechanics of these coordination crosslinks, which lays the ground for predictive and rational material design, has not yet been well addressed. Here we present a first-principles study of representative coordination complexes between metals and catechols. The results show that these crosslinks offer stiffness and strength near a covalent bond, which strongly depend on the coordination state and type of metals. This dependence is discussed by analyzing the nature of bonding between metals and catechols. The responsive mechanics of metal-coordination is further mapped from the single-molecule level to a networked material. The results presented here provide fundamental understanding and principles for material selection in metal-coordination-based applications.