查看更多>>摘要：The design of artificial water channels(AWCs)aims to mimic natural proteins that effectively mediate the selective transport of water across the bilayer and artificial polymeric membranes.Currently,impressive progress on synthetic backbones,including self-assembled channels,helical unimolecular,and other functional organic molecules,has been made to pro-vide artificial alternatives and applications in real sys-tems for promising product development.In this review,several synthetic channels exploited during the last few years are summarized according to their back-bone architecture for water transport and ion trans-port respectively,showing their potential as natural transporter analogs and the importance of AWCs for industrial,environmental,and medical applications.
查看更多>>摘要：Purely organic room-temperature phosphors,which have received extensive attention as emerging state-of-the-art luminescent materials in various fields,have a longer lifetime than fluorophores.The energy gap law and El-Sayed's rule provide clear design principles for the development of organic room-temperature phosphorescence.Therefore,the incorporation of heteroatoms(such as sulfur and phosphorus)usually promotes the intersystem crossing rate and increases the 3(π,π*)configuration to realize long lifetimes.Furthermore,boron-containing phosphors not only display excellent phosphorescence properties but al-so expand El-Sayed's rule without(n,π*)transitions.This review summarizes recent work on organic phos-phorescence of heterocycles with boron,sulfur,and phosphorus heteroatoms and highlights the signifi-cance of the guidelines for constructing efficient phosphorescence molecules.This work is instrumen-tal in further diversifying the pool of phosphorescent molecules and developing new and effective design strategies.
查看更多>>摘要：Cellular heterogeneity is essential for the physiologi-cal functions of organisms,and precise interpretation of the relevant biological mechanisms involved requires accurate measurement of biomolecules,in-cluding DNA,RNA,proteins,and metabolites at the single-cell level.Cellular metabolites react most rap-idly to environmental and biochemical changes such that their detection is a critical step in determining the physiological state of cells.However,their limited amounts,structural diversity,and significant content variation render single-cell metabolomics analysis technically challenging.Mass spectrometry,with its high sensitivity,good selectivity,and wide dynamic range,has been widely used in the single-cell analysis in recent years.In terms of ionization techniques,there are four main types of single-cell mass spec-trometry methods:nano-electrospray ionization mass spectrometry,matrix-assisted laser desorption/ioni-zation mass spectrometry,secondary ion mass spec-trometry,and dielectric barrier discharge ionization mass spectrometry.In this mini review,the progress of single-cell mass spectrometry methodologies and da-ta processing strategies are summarized,and the future trends in single-cell mass spectrometry are outlined.
查看更多>>摘要：Herein we report the first[4+1]cyclization-aromati-zation reaction of acylsilanes and α,β-unsaturated ketones.The unprecedented visible-light-induced re-action proceeded through mild conditions without addition of any catalyst or additive,affording a variety of furans with broad substrate scope and good func-tional-group tolerance.The synthetic utility of the method was demonstrated by various downstream transformations of the otherwise difficult-to-access sulfone-containing silyl furans.The mechanism study reveals that 1,4-diketones are not likely to be the intermediates of the reaction.
查看更多>>摘要：Single electron transition reactions between amines(Lewis base)and B(C6F5)3(Lewis acid)in coopera-tion with benzoquinones gave rise to a frustrated radical pair 3 and a nonfrustrated radical pair 4.Both of them were isolated as stable crystals and studied by single-crystal X-ray diffraction,superconducting quantum interference device measurements,elec-tron paramagnetic resonance,nuclear magnetic res-onance,and UV-vis spectroscopy.Antiferromagnetic exchange coupling was observed among both 3 and 4.Radical anion and cation are basically separated in 3,while 4 featured a relatively strong anion-cation π-π stacking interaction.This work demonstrated that the Lewis acid coupled electron transfer is an efficient way to prepare stable radical ion pairs.
查看更多>>摘要：The facile construction of chiral quaternary α-alkenylated pyrrolidinones is a long-term challenge in organic synthesis.The asymmetric difunctionaliza-tion of 1,3-dienes represents the most compelling tool for assembling alkenylated compounds by regiose-lective 1,2-or 1,4-difunctionalization.Nevertheless,the manipulation of unactivated 1,3-dienes to forge the quarternary stereogenic center still remains large-ly underdeveloped.Herein,we disclose a nickel-catalyzed asymmetric 1,4-arylcarbamoylation of unactivated 1,3-dienes tethered on carbamoyl fluo-ride with readily available arylboronic acids,provid-ing rapid access to the enantioenriched α-alkenylated pyrrolidinones bearing the quaternary stereogenic center in high yields with broad functional group tolerance.Moreover,this chiral ligand-controlled asymmetric transformation overcomes the intrinsic substrate control with a preexisting chiral center.
查看更多>>摘要：Revealing structural isomerization in metal clusters would bridge a huge structural gap between small molecular isomerization and solid-solid phase trans-formation.However,genuine structural isomerism in metal clusters is still rare.In this work,we report the first example of structural isomerism in Cu clusters.By utilizing the coordination flexibility of alkyne to en-able the migration of partial Cu atoms in Cu metal cores,two Cu15 cluster complexes(Cu15-a and Cu15-c)possessing identical composition but different metal core structures have been successfully isolated.Inter-estingly,although the structure of Cu15-a can be retained in CH2Cl2 solution below 27 ℃,it will gradu-ally change to give an intermediate state,Cu15-b,as the temperature rises(at about 31 ℃)before it even-tually transforms into Cu15-c(at 40～65 ℃).Signifi-cantly,atomically precise Cu15-b clearly provides footprints for tracing the thermal migration process of Cu atoms during the thermal transformation from Cu15-a to Cu15-c.In addition,Cu15-a and Cu15-c ex-hibit diverse crystallization-induced emission en-hancement phenomena.Crystalline Cu15-c displays redshifted photoluminescence(820 nm)compared with Cu15-a(726 nm)due to the shorter mean Cu…Cu distance in Cu15-c.Notwithstanding,crystalline Cu15-a exhibits much more intense photoluminescence at room temperature than that in Cu15-c,which might be attributed to the stronger intermolecular C-H…π inter-actions in Cu15-a.These results indicate that cluster isomerism provides valuable opportunities for insight into the structure-property relationships and under-standing the complex evolution of phase transforma-tion in nanometallic solids.
查看更多>>摘要：By adjusting the bond angle and stereocontrol sub-stituent of the chiral bicyclic imidazole catalysts,direct enantioselective C-acetylation of indolones and their sequencial pattern have been successfully developed.Indolones bearing a quaternary stereocenter were synthesized with satisfactory yields and excellent enantioselectivities(up to 97％ee).The reaction can be realized with 410 turnover numbers,and the pro-ducts can be transformed into several functional com-pounds via simple derivations of the acetyl group.
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