Eley–Rideal model of heterogeneous catalytic carbamate formation based on CO 2 –MEA absorptions with CaCO 3 , MgCO 3 and BaCO 3

The mechanism was proposed of heterogeneous catalytic CO 2 absorptions with primary/secondary amines involving ‘catalytic carbamate formation’. Compared with the non-catalytic ‘Zwitterion mechanism’, this Eley–Rideal model was proposed for CO 2 + RR′NH with MCO 3 (M = Ca, Mg, and Ba) with four elementary reaction steps: (B1) amine adsorption, (B2) Zwitterion formation, (B3) carbamate formation, and (B4) carbamate desorption. The rate law if determining step of each elementary step was generated based on ‘steady-state approximation’. Furthermore, the solid chemicals were characterized by SEM and BET, and this rate model was verified with 39 sets of experimental datasets of catalytic CO 2 –MEA absorptions with the existence of 0–25 g CaCO 3 , MgCO 3 and BaCO 3 . The results indicated that the rate-determining step was B1 as amine adsorption onto solid surface, which was pseudo-first-order for MEA. This was the first time that the Eley–Rideal model had been adopted onto the reactions of CO 2 + primary/secondary amines over alkaline earth metal carbonate (MCO 3 ).

Sudden polarization and zwitterion formation as a pseudo-Jahn–Teller effect: a new insight into the photochemistry of alkenes

We show that the intermediates of photochemical reactions—sudden polarization and zwitterion formations—are consequences of the pseudo-Jahn–Teller effect (PJTE), which facilitates a better understanding, rationalization, prediction, and manipulation of the corresponding chemical and biological processes.

Zwitterion formation and subsequent carboxylate–pyridinium NH synthon generation through isomerization of 2-anilinonicotinic acid

Structural isomerization of 2-anilinonicotinic acids to 4-anilinonicotinic acids leads to an increase of ΔpKa, thus leading to the formation of a carboxylate–pyridinium NH dimer in the solid state.

Alkylideneborate zwitterions and C–C coupling by atypical diboration of electron-rich alkynes

The combination of electron-rich diaminoalkynes and ditopic Lewis acids diboranes(4) leads to unusual diboration reactions involving internal Lewis adduct and zwitterion formation and C–C bond formation.