RESUMO
A novel method for the highly efficient and reversible capture of CO in carbanion-functionalized ionic liquids (ILs) by a C-site interaction is reported. Because of its supernucleophilicity, the carbanion in ILs could absorb CO efficiently. As a result, a relatively high absorption capacity for CO (up to 0.046â mol mol-1 ) was achieved under ambient conditions, compared with CO solubility in a commonly used IL [Bmim][Tf2 N] (2×10-3 â mol mol-1 ). The results of quantum mechanical calculations and spectroscopic investigation confirmed that the chemical interaction between the C-site in the carbanion and CO resulted in the superior CO absorption capacities. Furthermore, the subsequent conversion of captured CO into valuable chemicals with good reactivity was also realized through the alkoxycarbonylation reaction under mild conditions. Highly efficient CO absorption by carbanion-functionalized ILs provides a new way of separating and converting CO.
Assuntos
Ânions/química , Monóxido de Carbono/química , Líquidos Iônicos/química , Sítios de Ligação , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Teoria da Densidade Funcional , Estrutura Molecular , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
A new strategy for multi-molar absorption of CO2 is reported based on activating a carboxylate group in amino acid ionic liquids. It was illustrated that introducing an electron-withdrawing site to amino acid anions could reduce the negative inductive effect of the amino group while simultaneously activating the carboxylate group to interact with CO2 very efficiently. An extremely high absorption capacity of CO2 (up to 1.69â mol mol(-1) ) in aminopolycarboxylate-based amino acid ionic liquids was thus achieved. The evidence of spectroscopic investigations and quantum-chemical calculations confirmed the interactions between two kinds of sites in the anion and CO2 that resulted in superior CO2 capacities.
RESUMO
We present a rational design and synthesis of a novel porous pyridine-functionalized polycarbazole for efficient CO2 capture based on the density functional theory calculations. The task-specific polymer, generated through a one-step FeCl3-catalyzed oxidative coupling reaction, exhibits a superior CO2 uptake at 1.0 bar and 273 K (5.57 mmol g(-1)).