Macrocyclic hosts capable of specific molecular recognition are crucial for advancing supramolecular chemistry,but rarely display phosphorescent activity.Herein,we report a new class of macrocycles,iminodibenzyl[n]are...Macrocyclic hosts capable of specific molecular recognition are crucial for advancing supramolecular chemistry,but rarely display phosphorescent activity.Herein,we report a new class of macrocycles,iminodibenzyl[n]arenes(IB[n]As,n=3,4),that exhibit unusual green room-temperature phosphorescence(RTP).The uniqueness of IB[4]A is a concave double-cavity structure with an RTP lifetime of 3.82 ms.Although IB[3]A has a shorter RTP lifetime of 1.91 ms,it features outstanding size-selective binding for vip molecules due to its tendency for prismatic cavity formation.This was supported by single-crystal analysis,density functional theory calculations,and host-vip binding experiments involving eight different-sized cationic vips.The structural complementarity between IB[3]A and 1,4-diazabicyclo[2.2.2]octane cation G4 is particularly notable,affording a stronger affinity(K=2524 M^(-1))compared to others.Accordingly,encapsulating this suitable“vip rivet”induces a more rigid microenvironment,prolonging the RTP lifetime to 8.99 ms.This study bridges selective molecular recognition and RTP modulation in macrocyclic hosts,facilitating the architectural design of complex molecules and offering diverse post-synthetic tunability for phosphorescent compounds.展开更多
Merging tetraphenylethylene(TPE)into cyclic skeletons endows fluorescent sensing capabilities for pillar[6]arenes aggregates,but results in losing their host-vip recognition function in dilute solutions.Inspired by ...Merging tetraphenylethylene(TPE)into cyclic skeletons endows fluorescent sensing capabilities for pillar[6]arenes aggregates,but results in losing their host-vip recognition function in dilute solutions.Inspired by natural enzymes,here we describe a series of TPE-based cyclo[6]arenes(termed TPz,TDz,and TTz)with endo-functionalized cavities containing inward-directed diazine motifs(pyrazine,pyridazine,and phthalazine)that act as hydrogen-bond acceptor sites.Combining electrostatic potential analysis and host-vip binding studies reveals that subtle variations in these diazine motifs substantially affect charge distribution and hydrogen-bond interactions within the internal microenvironment.These differences translate into disparate host-vip affinities,with TTz exhibiting the optimal performance.Unlike TPz,which recognizes vips only in aggregate states,1,2-diazine-modified TDz and TTz possess dual-state recognition functionality.They enable size-selective binding for cationic vips in dilute solutions and sensitive fluorescence detection of nitrophenol pollutants in aggregate states through a photoinduced electron transfer-driven static quenching mechanism.This study underscores the potential of 1,2-diazine motifs as transformative hydrogen-bond acceptors for biomimetic host models with emergent properties.展开更多
基金supported by the National Natural Science Foundation of China(22401064,22161017)the Innovational Fund for Scientific and Technological Personnel of Hainan Province(KJRC2023D34)+1 种基金the Hainan Provincial Natural Science Foundation of China(224QN184)the Research Start-up Fund of Hainan University(KYQD(ZR)23037)。
文摘Macrocyclic hosts capable of specific molecular recognition are crucial for advancing supramolecular chemistry,but rarely display phosphorescent activity.Herein,we report a new class of macrocycles,iminodibenzyl[n]arenes(IB[n]As,n=3,4),that exhibit unusual green room-temperature phosphorescence(RTP).The uniqueness of IB[4]A is a concave double-cavity structure with an RTP lifetime of 3.82 ms.Although IB[3]A has a shorter RTP lifetime of 1.91 ms,it features outstanding size-selective binding for vip molecules due to its tendency for prismatic cavity formation.This was supported by single-crystal analysis,density functional theory calculations,and host-vip binding experiments involving eight different-sized cationic vips.The structural complementarity between IB[3]A and 1,4-diazabicyclo[2.2.2]octane cation G4 is particularly notable,affording a stronger affinity(K=2524 M^(-1))compared to others.Accordingly,encapsulating this suitable“vip rivet”induces a more rigid microenvironment,prolonging the RTP lifetime to 8.99 ms.This study bridges selective molecular recognition and RTP modulation in macrocyclic hosts,facilitating the architectural design of complex molecules and offering diverse post-synthetic tunability for phosphorescent compounds.
基金support was provided by the National Natural Science Foundation of China(22401064 and 22161017)the Innovational Fund for Scientific and Technological Personnel of Hainan Province(KJRC2023D34)+1 种基金the Hainan Provincial Natural Science Foundation of China(224QN184)the Research Start-up Fund of Hainan University(KYQD(ZR)23037).
文摘Merging tetraphenylethylene(TPE)into cyclic skeletons endows fluorescent sensing capabilities for pillar[6]arenes aggregates,but results in losing their host-vip recognition function in dilute solutions.Inspired by natural enzymes,here we describe a series of TPE-based cyclo[6]arenes(termed TPz,TDz,and TTz)with endo-functionalized cavities containing inward-directed diazine motifs(pyrazine,pyridazine,and phthalazine)that act as hydrogen-bond acceptor sites.Combining electrostatic potential analysis and host-vip binding studies reveals that subtle variations in these diazine motifs substantially affect charge distribution and hydrogen-bond interactions within the internal microenvironment.These differences translate into disparate host-vip affinities,with TTz exhibiting the optimal performance.Unlike TPz,which recognizes vips only in aggregate states,1,2-diazine-modified TDz and TTz possess dual-state recognition functionality.They enable size-selective binding for cationic vips in dilute solutions and sensitive fluorescence detection of nitrophenol pollutants in aggregate states through a photoinduced electron transfer-driven static quenching mechanism.This study underscores the potential of 1,2-diazine motifs as transformative hydrogen-bond acceptors for biomimetic host models with emergent properties.
