查看更多>>摘要：A general and convenient photoredox-catalyzed acylation and alkylcyanation of MBH acetates has been established,enabling the as-sembly of the C(sp2)-C(sp3)bond by a nitrogen-centered radical strategy for the synthesis of trisubstituted alkenes in moderate to excellent chemical yields(48 examples in total).The reaction of MBH acetates with acyl(indanone)oxime esters afforded trisubsti-tuted alkenes containing 1,4-dicarbonyl groups.Interestingly,the use of Eosin Y as a photocatalyst in the catalytic system resulted in the formation of distal cyano group-anchored trisubstituted alkenes via deconstructive functionalization of cycloketone oxime esters.Notably,these resulting 1,4-dicarbonyl compounds could be applied to late-stage transformations,providing important methods for the synthesis of dihydropyridazin-3(2H)-one.
查看更多>>摘要：Duration-tunable afterglow materials have garnered considerable attention in various applications.Herein,carbon dots(CDs)-based long persistent luminescence(LPL)composites with a tunable duration in an ultrawide range of seconds-to-hours levels were de-signed and prepared for the first time.In contrast to the established CD-based afterglow materials,we reported that CD-based composites exhibit LPL in the form of exciplexes and long-lived charge-separated states,enabling the LPL to be prolonged from sev-eral seconds to over one hour,exceeding the typical regulation range(limited to 1 min).Further studies revealed that the relation-ship between the excited and charge-transfer states of CDs plays a pivotal role in activating the LPL and regulating its duration.Fur-thermore,these composites exhibited high photoluminescence(PL)quantum yields of up to 60.63％,and their LPL was robust under ambient conditions,even in aqueous media.Their robust and superior LPL performance endows these composites with a strong competitive advantage in dynamic display systems,such as tags for time-resolved data encryption and displays of the remaining time of takeaways.This study offers an approach to preparing CDs-based LPL composites with tunable durations and may provide new in-sights for the development of rare-earth-free LPL materials.
查看更多>>摘要：Polymer mechanochemistry on reactive species has attracted more and more attentions over the past 20 years,as the mechano-chemical generation of reactive species has a great potential in developing different polymeric materials for various purposes,such as stress detection,self-healing,self-strengthening,controllable degradation and release of small molecules.In this review,we first discuss the recent progress on polymer mechanochemistry of the reactive species that are generated from the mechanochemical reactions of mechanophores.Five types of reactive species,including radical,zwitterion,ionic,carbene and neutral intermediates,and their applications were reviewed in detail.Since mechanochemical reactions are sensitive to the mechanophore structure and polymer framework,we then discuss how mechanophore isomerism,polymer structure,polymer attachment point,and polymer architecture influence the mechanophore activation.At last,we provide our perspectives on the polymer mechanochemistry of re-active species.
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