Molecular-Level Structure-Property Relationships In Biogenic Calcium Carbonates: The Unique Insights Of Solid-State Nmr Spectroscopy

The biomineralization process produces materials with exceptional microscopic, morphologic, and mechanical qualities, which are finely tuned for specific functionality. This control of the properties is obtained through interactions with bioorganic and inorganic molecules that regulate the formation and/or become incorporated into the final biomineral. Although the interfacial regions comprise a minute fraction of the mineral, they are of paramount importance. Modern solid-state NMR spectroscopy techniques enable to focus on these biomineral interfaces and defects, and to determine their molecular-level structures; a task that is barely attainable by other methods. Biogenic calcium carbonates are highly abundant and extensively investigated. Currently, only a limited number of such systems have been studied by solid-state NMR spectroscopy. Reviewing these herein, we demonstrate the power and adequacy of NMR spectroscopy to probe biogenic systems and highlight many questions that remain open and can benefit from further application of advanced NMR spectroscopy techniques.