Secondary Sphere Effects on Porous Polymeric Organocatalysts for CO2 Transformations: Subtle Modifications Resulting in Superior Performance.
ACS Appl Mater Interfaces
; 12(29): 32827-32833, 2020 Jul 22.
Article
en En
| MEDLINE
| ID: mdl-32597167
Albeit harnessing secondary sphere interactions to exert control over the reaction outcomes has primarily been applied to enzymatic and organometallic catalysis, there are seldom any studies that introduce outer-sphere modifiers into organocatalysts. This is even less in the corresponding heterogeneous catalytic system. In this contribution, we experimentally and computationally investigate the role of secondary effects in the reactivity of bromide anions toward CO2 transformations. Six pyridinium cationic porous frameworks have been synthesized and fully characterized. Structure-activity relationships and kinetics show that the type and the location of the substituents on the cationic framework have a significant impact on the nucleophilic reactivity of their bromide counter anion. Specifically, the attachment of amine substituent to the ortho position relative to a pyridinium motif produces a remarkably efficient catalyst for CO2 transformation, by a factor of six times greater in comparison to the pristine pyridinium-based polymer. The hydrogen-bond-interaction-promoted reagent activation and enhanced delocalization ability of bromide counter anion are believed to be the key to driving the reaction toward CO2 utilization. These observations, therefore, champion the leverage of secondary interaction for optimizing the reactivity of organocatalysts.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
ACS Appl Mater Interfaces
Asunto de la revista:
BIOTECNOLOGIA
/
ENGENHARIA BIOMEDICA
Año:
2020
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Estados Unidos