ABSTRACT
The conversion of CO2 to generate high-value-added chemicals has become one of the hot research topics in green synthesis. Thereinto, the cyclization reaction of propargylic amines with CO2 is highly attractive because the resultant oxazolidinones are widely found in pharmaceutical chemistry. Cu(I)-based metal-organic frameworks (MOFs) as catalysts exhibit promising application prospects for CO2 conversion. However, their practical application was greatly limited due to Cu(I) being liable to disproportionation or oxidization. Herein, the solid copper(I) iodide thorium-based porous framework {[Cu5I6Th6(µ3-O)4(µ3-OH)4(H2O)10(L)10]·OH·4DMF·H2O}n (1) (HL = 2-methylpyridine-4-carboxylic acid) constructed by [Th6] clusters and [CuxIy] subunits was successfully prepared and structurally characterized. To our knowledge, this is the first copper(I) iodide-based actinide organic framework. Catalytic investigations indicate that 1 can effectively catalyze the cyclization of propargylic amines with CO2 under ambient conditions, which can be reused at least five times without a remarkable decline of catalytic activity. Importantly, 1 exhibits excellent chemical stability and the oxidation state of Cu(I) in it can remain stable under various conditions. This work can provide a valuable strategy for the synthesis of stable Cu(I)-MOF materials.
ABSTRACT
Purpose: Few studies examined variables that might explain the link between perceived COVID-19 stress and suicidal ideation. The present study tested a multiple-sequence mediation model with family cohesion, thwarted belongingness, and perceived burdensomeness as mediators. Methods: The current study surveyed 1098 college students in China using questionnaires concerning perceived COVID-19 stress, family cohesion, unmet interpersonal needs, and suicide ideation. Results: Perceived COVID-19 stress was significantly associated with family cohesion, thwarted belongingness, perceived burdensomeness, and suicidal ideation. Family cohesion, thwarted belongingness, and perceived burdensomeness mediated the relationship between perceived COVID-19 stress and suicidal ideation separately. These factors also had multiple sequence-mediated effects between perceived COVID-19 stress and suicidal ideation. Conclusion: The study revealed pathways from perceived COVID-19 stress to suicidal ideation and suggested that interventions to increase family cohesion and reduce one's unmet interpersonal needs were beneficial in decreasing individuals' suicidal ideation.
ABSTRACT
Purpose: Few studies have explored factors that may account for potential mechanisms between perceived coronavirus disease 2019 (COVID-19) stress and online aggression. The current study examined a moderated mediation model with anxiety as a mediator and perceived anonymity as a moderator. Methods: A cross-sectional study was conducted. 3,069 participants across China completed scales assessing perceived COVID-19 stress, anxiety, online aggression, and perceived anonymity. Results: Perceived COVID-19 stress was positively related to online aggression. The association between perceived COVID-19 stress and online aggression was mediated by anxiety. Besides, the relationship between perceived COVID-19 stress and online aggression, as well as the relationship between anxiety and online aggression were moderated by perceived anonymity. Conclusion: This study explains the possible potential mechanisms for reducing online aggression in the context of COVID-19. In order to intervene in online aggression, psychological strategies are supposed to be drawn to reduce anxiety and perceived anonymity.
