A poly(l-glutamic acid)/β-cyclodextrin (P-l-Glu/β-CD)-modified glassy carbon electrode (GCE) was prepared by electrochemical polymerization of l-glutamic acid on GCE and subsequent self-assembly of β-CD onto the obtained P-l-Glu. Electrochemical recognition of tryptophan (Trp) enantiomers with the P-l-Glu/β-CD was investigated by differential pulse voltammetry (DPV), and the results show that Trp enantiomers can be effectively recognized at the P-l-Glu/β-CD-modified GCE. It is also interesting to find that temperature plays a crucial role in the enantioselective recognition, which is evidenced by the variable-temperature UV spectra of the inclusion complexes of Trp enantiomers and β-CD. Under optimum conditions, the oxidation peak current ratio of l-Trp to d-Trp could reach 2.30, which is attributed to the stereoselectivity of β-CD to the enantiomeric pair of Trp.

Ferrocene is classically regarded as being highly inert owing to the large dissociation energy of metal-cyclopentadienyl (Cp) bonds. We show that the Fe-Cp bond in ferrocene is the preferential site of mechanochemical scission in the pulsed ultrasonication of main-chain ferrocene-containing polybutadiene-derived polymers. Quantitative studies reveal that the Fe-Cp bond is similar in strength to the carbon-nitrogen bond of an azobisdialkylnitrile (bond dissociation energy < −0 kcal/mol), despite the significantly higher Fe-Cp bond dissociation energy (approximately 90 kcal/mol). Mechanistic studies are consistent with a predominately heterolytic mechanism of chain scission. DFT calculations provide insights into the origins of ferrocene’s mechanical lability.

Cations are crucial components in emerging functional polyelectrolytes for a myriad of applications. Rapid development in this area necessitates the exploration of new cations with advanced properties. Herein we describe a combination of computational and experimental design of cobaltocene metallo-cations that have distinct electronic and redox properties. One of the direct outcomes on the first synthesis of a complete set of cation derivatives is to discover highly stable cations, which are further integrated to construct metallo-polyelectrolytes as anion-exchange membranes in solid-state alkaline fuel cells. The device performance of these polyelectrolytes under highly basic and oxidative environments is competitive with many organo-polyelectrolytes.

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