Gehlen, Marcelo H.
Foltran, Larissa S.
Kienle, Daniel F.
Schwartz, Daniel K.
Total Authors: 4
 Univ Sao Paulo, Inst Chem Sao Carlos, Dept Phys Chem, BR-13566590 Sao Carlos, SP - Brazil
 Univ Colorado, Dept Chem & Biol Engn, Boulder, CO 80309 - USA
Total Affiliations: 2
Journal of Physical Chemistry Letters;
NOV 19 2020.
Web of Science Citations:
While single-molecule (SM) methods have provided new insights to various catalytic processes, bimolecular reactions have been particularly challenging to study. Here, the fluorogenic Knoevenagel condensation of an aromatic aldehyde with methyl cyanoacetate promoted by surface-immobilized piperazine is quantitatively characterized using super-resolution fluorescence imaging and stochastic analysis using hidden Markov modeling (HMM). Notably, the SM results suggest that the reaction follows the iminium intermediate pathway before the formation of a fluorescent product with intramolecular charge-transfer character. Moreover, the overall process is limited by the turnover rate of the catalyst, which is involved in multiple steps along the reaction coordinate. (AU)