Quantification and Prediction of Imine Formation Kinetics in Aqueous Solution by Microfluidic NMR Spectroscopy.

Quantitatively predicting the reactivity of dynamic covalent reaction is essential to understand and rationally design complex structures and reaction networks. Herein, the reactivity of aldehydes and amines in various rapid imine formation in aqueous solution by microfluidic NMR spectroscopy was quantified. Investigation of reaction kinetics allowed to quantify the forward rate constants k+ by an empirical equation, of which three independent parameters were introduced as reactivity parameters of aldehydes (SE , E) and amines (N). Furthermore, these reactivity parameters were successfully used to predict the unknown forward rate constants of imine formation. Finally, two competitive reaction networks were rationally designed based on the proposed reactivity parameters. Our work has demonstrated the capability of microfluidic NMR spectroscopy in quantifying the kinetics of label-free chemical reactions, especially rapid reactions that are complete in minutes.

Cyclopentadienone Derivative Dimers as Tunable Photoswitches.

A series of photoswitchable cyclopentadienone derivative dimers bearing bromo, thienyl, 4-(dimethylamino)phenyl, 3-pyridinyl, 4-nitrophenyl and cyano groups was designed and facilely synthesized. Photoswitching properties such as the photoconversions in the photostationary state (PSS), the thermal kinetics and thermal half-lives of photoisomers were systematically investigated. These photoswitches show high fatigue resistance and large photoconversions in the PSS. This work proves that the photoswitching properties of photoswitches based on cyclopentadienone dimers can be tuned by substitution groups and also pave the way to functionalize the cyclopentadienone derivative dimer-based photoswitch, which is important for its future applications.

Cocrystallization of Imide-Fused Corannulene Derivatives and C60 : Guest-Induced Conformational Switching and 1:1 Segregated Packing.

A pair of interconvertible stereoisomers of imide-fused corannulene derivatives was mixed with C60 , which resulted in cocrystallization into a 1:1 segregated packing motif through concave-convex π-π interactions. Only one conformation was observed in the cocrystal owing to guest-induced conformational switching. The 1D assemblies of the complex showed promising applications in organic electronics.