Cyclooctatetraene(COT)attachment to fluorophores(“self-healing”dyes)is known for quenching reac-tive triplet states via triplet-state energy transfer(TET),enhancing photostability.However,COT’s impact on singlet st...Cyclooctatetraene(COT)attachment to fluorophores(“self-healing”dyes)is known for quenching reac-tive triplet states via triplet-state energy transfer(TET),enhancing photostability.However,COT’s impact on singlet states remains unclear.Quantum calculations reveal that COT induces energy transfer to dark states in deep blue dyes while promoting photoinduced electron transfer(PET)and intersystem crossing(ISC)in visible dyes,potentially compromising brightness and/or photostability.To address this,we pro-pose the use of △E descriptor to optimize COT’s effects.Our findings uncover COT’s multifaceted impact.These insights will guide the development of superior triplet state quenchers and photostable dyes.展开更多
The reaction of NdCl_3 with lithium methylnaphthalene in 1:2 mole ratio in THF generates black powder. The powder reacts with cyclooctatetraene(COT)in THF to form the title complex.[Li(THF)_4Nd(C_8H_8)_2]· 2THF c...The reaction of NdCl_3 with lithium methylnaphthalene in 1:2 mole ratio in THF generates black powder. The powder reacts with cyclooctatetraene(COT)in THF to form the title complex.[Li(THF)_4Nd(C_8H_8)_2]· 2THF crystallizes in the monoclinic space group P2/c with unit-cell dimensions a=1.7858(7)nm, h=1.3243(4)nm,c=1.8086(6)nm.β=106.52(4)°,V=4.10 nm^3 and D_c=1.268 g/cm^3 for Z=4. F(000)=1660,R=0.0774,R_n=0.0733.The complex consists of discrete ion-pair and two THF molecules adduct.In the anion,the neodymium atom is coordinated by two COT rings.The structure of the cation shows that the lithium atom is attached with THF molecules only.展开更多
The aromaticity and electronic properties of monocyclic or polycyclicπ-conjugated molecules have been widely studied.However,the related research on fullyπ-conjugated multicyclic macrocycles(MMCs)remains limited mai...The aromaticity and electronic properties of monocyclic or polycyclicπ-conjugated molecules have been widely studied.However,the related research on fullyπ-conjugated multicyclic macrocycles(MMCs)remains limited mainly due to the synthetic challenges.Herein,we report a straightforward synthesis of two MMCs(T8 and T12)in which unilateral and bilateral thiophene-based macrocycles merged with a cyclooctatetrathiophene unit by employing intramolecular Yamamoto coupling reactions of the designed precursors(8 and 12)followed by oxidative dehydrogenation.The neural compounds,their dications,and even tetracations were isolated in single-crystal form.Their geometry,aromaticity,open-shell diradical character,and physical properties were investigated by experiments such as X-ray crystallographic analysis,nuclear magnetic resonance(NMR),electron spin resonance(ESR),and theoretical calculations,which revealed changes in local/global aromatic/antiaromatic characteristics at different oxidation states.展开更多
基金the support from the Ministry of EducationSingapore (MOE,No.MOET2EP10120-0007)+4 种基金A^(*)STAR under its Advanced Manufacturing and Engineering Program (No.A2083c0051)the SUTD Kickstarter Initiative (No.SKI 2021_01_01)supported by QMUL Research-IT for computational resources,and the ARCHER UK National Supercomputing Service (No.EP/X035859/1) via the Materials Chemistry Consortiumthe Molecular Modelling Hub for computational resources,MMM Hub,which is partially funded by EPSRC (No.EP/T022213/1)Leverhulme Trust (No.RPG-2019-122) for funding
文摘Cyclooctatetraene(COT)attachment to fluorophores(“self-healing”dyes)is known for quenching reac-tive triplet states via triplet-state energy transfer(TET),enhancing photostability.However,COT’s impact on singlet states remains unclear.Quantum calculations reveal that COT induces energy transfer to dark states in deep blue dyes while promoting photoinduced electron transfer(PET)and intersystem crossing(ISC)in visible dyes,potentially compromising brightness and/or photostability.To address this,we pro-pose the use of △E descriptor to optimize COT’s effects.Our findings uncover COT’s multifaceted impact.These insights will guide the development of superior triplet state quenchers and photostable dyes.
文摘The reaction of NdCl_3 with lithium methylnaphthalene in 1:2 mole ratio in THF generates black powder. The powder reacts with cyclooctatetraene(COT)in THF to form the title complex.[Li(THF)_4Nd(C_8H_8)_2]· 2THF crystallizes in the monoclinic space group P2/c with unit-cell dimensions a=1.7858(7)nm, h=1.3243(4)nm,c=1.8086(6)nm.β=106.52(4)°,V=4.10 nm^3 and D_c=1.268 g/cm^3 for Z=4. F(000)=1660,R=0.0774,R_n=0.0733.The complex consists of discrete ion-pair and two THF molecules adduct.In the anion,the neodymium atom is coordinated by two COT rings.The structure of the cation shows that the lithium atom is attached with THF molecules only.
基金supported financially by the Singapore Ministry of Education(MOE)Academic Research Fund(AcRF)Tier 2 grant(MOE-T2EP10222-0003)the Agency for Science,Technology and Research Manufacturing,Trade,and Connectivity(A*STAR MTC)project,Singapore(M22K2c0083).
文摘The aromaticity and electronic properties of monocyclic or polycyclicπ-conjugated molecules have been widely studied.However,the related research on fullyπ-conjugated multicyclic macrocycles(MMCs)remains limited mainly due to the synthetic challenges.Herein,we report a straightforward synthesis of two MMCs(T8 and T12)in which unilateral and bilateral thiophene-based macrocycles merged with a cyclooctatetrathiophene unit by employing intramolecular Yamamoto coupling reactions of the designed precursors(8 and 12)followed by oxidative dehydrogenation.The neural compounds,their dications,and even tetracations were isolated in single-crystal form.Their geometry,aromaticity,open-shell diradical character,and physical properties were investigated by experiments such as X-ray crystallographic analysis,nuclear magnetic resonance(NMR),electron spin resonance(ESR),and theoretical calculations,which revealed changes in local/global aromatic/antiaromatic characteristics at different oxidation states.
