Cooperativity in Photofoldamer Chloride Double Helices Turned On with Sequences and Solvents, Around with Guests, and Off with Light.

Photofoldamers are sequence-defined receptors capable of switching guest binding on and off. When two foldamer strands wrap around the guest into 2:1 double helical complexes, cooperativity emerges, and with it comes the possibility to switch cooperativity with light and other stimuli. We use lessons from nonswitchable sequence isomers of aryl-triazole foldamers to guide how to vary the sequence location of azobenzenes from the end () to the interior () and report their impact on the cooperative formation of 2:1 complexes with Cl.

High-fidelity Recognition of Organotrifluoroborate Anions (R-BF ) as Designer Guest Molecules.

The recognition of boron compounds is well developed as boronic acids but untapped as organotrifluoroborate anions (R-BF ). We are exploring the development of these and other designer anions as anion-recognition motifs by considering them as substituted versions of the parent inorganic ion. To this end, we demonstrate strong and reliable binding of organic trifluoroborates, R-BF , by cyanostar macrocycles that are size-complementary to the inorganic BF progenitors.

Electrospinning Hetero-Nanofibers of Fe C-Mo C/Nitrogen-Doped-Carbon as Efficient Electrocatalysts for Hydrogen Evolution.

Heterostructured electrocatalysts with multiple active components are expected to synchronously address the two elementary steps in the hydrogen evolution reaction (HER), which require varied hydrogen-binding strength on the catalyst surface. Herein, electrospinning followed by a pyrolysis is introduced to design Fe C-Mo C/nitrogen-doped carbon (Fe C-Mo C/NC) hetero-nanofibers (HNFs) with tunable composition, leading to abundant Fe C-Mo C hetero-interfaces for synergy in electrocatalysis. Owing to the strong hydrogen binding on Mo C and the relatively weak one on Fe C, the hetero-interfaces of Fe C-Mo C remarkably promote HER kinetics and intrinsic activity.