Phenolic ionic liquids for the efficient and reversible capture of CO(2) were designed and prepared from phosphonium hydroxide and substituted phenols. The electron-withdrawing or electron-donating ability, position, and number of the substituents on the anion of these ionic liquids were correlated with the physicochemical properties of the ionic liquids. The results show that the stability, viscosity, and CO(2)-capturing ability of these ionic liquids were significantly affected by the substituents. Furthermore, the relationship between the decomposition temperature, the CO(2)-absorption capacity, and the basicity of these ionic liquids was quantitatively correlated and further rationalized by theoretical calculation. Indeed, these ionic liquids showed good stability, high absorption capacity, and low absorption enthalpy for CO(2) capture. This method, which tunes the physicochemical properties by making use of substituent effects in the anion of the ionic liquid, is important for the design of highly efficient and reversible methods for CO(2)-capture. This CO(2) capture process using diverse phenolic ionic liquids is a promising potential method for CO(2) absorption with both high absorption capacity and good reversibility.

The CO 2 -involved synthesis of chemicals is of significance. In this work, we found that 1-alkyl-3-methylimidazolium ionic liquids (ILs) had high efficiency for catalyzing the formylation of amines using CO 2 and phenylsilane at room temperature, producing the corresponding formylated products in excellent yields under the metal-free condition. The ILs acted as bifunctional catalysts, which activated the Si−H bond of phenylsilane to react with CO 2 to form the formoxysilane intermediate and simultaneously activated the amine substrate through the hydrogen bond. Moreover, the imidazolium cation and the anions of the ILs showed an excellent synergistic effect on catalyzing the formylation of amines.T he metal-free catalytic process can reduce cost and avoid the pollution caused by metals and is thus regarded as a green process, which has been paid much attention in chemical synthesis. 1 The CO 2 -involved chemical synthesis has been widely investigated in the past decades because CO 2 is a cheap, renewable, abundant, and green C1 resource. 2 However, due to the inherent thermodynamic and kinetic stability of CO 2 , it is challenging to activate CO 2 and achieve its transformation under mild conditions, especially at room temperature. So far, much work has focused on exploring efficient catalysts or catalytic systems for CO 2 conversion. 3 Metal-based catalysts have been widely applied in the CO 2 -involved chemical synthesis. 4 Recently, metal-free catalytic systems have been reported, showing promising potential for the CO 2 transformation. 5 For example, N-heterocyclic carbenes (NHCs) can activate CO 2 and catalyze CO 2 conversion at room temperature and atmospheric pressure. 5a However, compared with the metal catalysis, the nonmetal-catalyzed CO 2 conversion is still in an early stage.Ionic liquids (ILs), composed of organic cations and organic/inorganic anions, possess unique features such as high thermal and chemical stability, negligible vapor pressure, easy separation and tunable properties. Notably, most of the ILs are nonmetallic salts, which have displayed promising applications in many areas, especially in catalysis. 6 For example, task-specific ILs have realized the CO 2 capture and conversion under mild and metal-free conditions. Protic IL (e.g., [DBUH][TFE]) served as a bifunctional catalyst and achieved the CO 2 conversion at atmospheric pressure and room temperature in the synthesis of quinazoline-2,4(1H,3H)-diones from CO 2 and 2-aminobenzonitriles. 6d ILs are designable via selecting cations and anions and thus can provide the ILs specific functions as a result of the cooperative or synergistic effects between the ions. 7 As nonmetal catalysts, ILs are promising due to their advantages such as easy separation, recyclability, stability to air and water, and so on.Formamides are versatile chemicals and important building blocks, which are generally produced via the formylation of amines. Using CO 2 instead of toxic CO for the N-formylation reaction is an attractive and green alternative for the pr...

The outbreak of COVID-19 caused a worldwide public health crisis. Large-scale population screening is an effective means to control the spread of COVID-19. Reverse transcription− polymerase chain reaction (RT-qPCR) and serology assays are the most available techniques for SARS-CoV-2 detection; however, they suffer from either less sensitivity and accuracy or low instrument accessibility for screening. To balance the sensitivity, specificity, and test availability, here, we developed enhanced colorimetry, which is termed as a magnetic pull-down-assisted colorimetric method based on the CRISPR/Cas12a system (M-CDC), for SARS-CoV-2 detection. By this method, SARS-CoV-2 RNA from synthetic sequences and cultured viruses can be detected by the naked eye based on gold nanoparticle (AuNP) probes, with a detection limit of 50 RNA copies per reaction. With CRISPR/Cas12a-assisted detection, SARS-CoV-2 can be specifically distinguished from other closely related viruses. M-CDC was further used to analyze 41 clinical samples, whose performance was 95.12%, consistent with that of an approved Clinical RT-qPCR Diagnosis kit. The developed M-CDC method is not dependent on sophisticated instruments, which makes it potentially valuable to be applied for SARS-CoV-2 screening under poor conditions.