Strategies for Modulating Stabilities of Soft and Hard Hybrid Materials with Boron Clusters
Selective tuning of molecular properties such as solubility, melting point and crystallinity remains a crucial and unmet challenge towards unlocking new functionalities of molecular species. A common strategy towards engendering new properties of hybrid materials relies upon the mixing of traditionally hard inorganic fragments with softer organic components. Herein we disclose efforts made towards modulating the properties of hybrid materials using boron clusters. First, we demonstrate the capacity of monocarborane weakly coordinating anions [HCB11H11]- to overcome the classical moisture and oxygen instability exhibited by many anions employed in ionic liquid mixtures. After, we present a library of partially halogenated, dodecaborate-based weakly coordinating anions ([B12X9(OR)3]2- where X= Cl, Br and R= H, CH3) as alternatives to perhalogenated analogues which suffer low solubility in a variety of solvents. Overall, these materials augment the utility of weakly coordinating anions by providing highly stable and modular substrates capable of addressing challenges in many electrodeposition, battery, and ionic liquid applications. Next, we report the grafting of unprotected peptides and model protein with m-carborane using an organometallic approach to chemoselectively borylate cysteine (Cys) residues. Cys-borylated peptides show no additional toxicity compared to their Cys alkyl-based congeners and exhibited an enhanced resistance to proteolytic degradation. Finally, we describe developments in non-traditional teaching methods to engage mostly humanities and social science audiences in discussion of basic chemical principles in the pilot chemistry general elective course Material World.