The through-space and through-bond interactions of molecular orbitals in [2,2] paracyclophane are studied by the approved MS-X. method with overlapping atomic-sphere. The calculation results show the through-space in...The through-space and through-bond interactions of molecular orbitals in [2,2] paracyclophane are studied by the approved MS-X. method with overlapping atomic-sphere. The calculation results show the through-space interactions are exponential flareout with increasing of the distance of two orbitals, and.both through-space interactions and through-bond interactions are sizable but those two interactions oppose each other causing the net splitting to be small. Transition-state procedure was used to calculate ionization potentials, the results are in agreement with the PE-spectra.展开更多
Chiral[2.2]paracyclophane(PCP)is an intriguing prevalent scaffold widely utilized inπ-stacked polymers,luminescent materials,and asymmetric catalysis.However,current synthetic methods to access chiral PCP derivatives...Chiral[2.2]paracyclophane(PCP)is an intriguing prevalent scaffold widely utilized inπ-stacked polymers,luminescent materials,and asymmetric catalysis.However,current synthetic methods to access chiral PCP derivatives are still limited to physical separation and chemical or kinetic resolution.The direct desymmetric functionalization of nonsubstituted PCP has been a challenge since its discovery 70 years ago.Herein,we present a catalytic desymmetric dearomatization cyclopropanation reaction of PCP,providing rapid access to enantioenriched PCP cyclopropyl carboxylates with continuous tertiary/quaternary/quaternary chiral centers.The application of the chiral PCPs obtained has also been demonstrated by transformation to structurally novel C_(2) symmetric dirhodium catalysts.Of equal importance,detailed density functional theory calculations have been carried out to reveal the mechanism of this reaction.The key to this success is a structurally symmetric bulky C_(4) dirhodium catalyst:noncovalent interactions exist between substrates and catalysts,which form a cavity to host substrates,and mainly affect the regio-and enantioselectivity.展开更多
The development of circularly polarized multiresonant thermally activated delayed fluorescence materials with fast reverse intersystem crossing(RISC)process remains a challenge.Herein,we introduce high-lying excited s...The development of circularly polarized multiresonant thermally activated delayed fluorescence materials with fast reverse intersystem crossing(RISC)process remains a challenge.Herein,we introduce high-lying excited states to assist the RISC process.Through arranging two known MR-TADF emitters tCzBN and DiKTa at the pseudo-ortho position of a chiral skeleton paracyclophane(PCP),the excitedstate density was increased.The proof-of-concept emitter po-PCP-tCzBN-DiKTa shows nearly three times higher kRISC(5.31×10^(4) s^(−1))than PCP-tCzBN(1.73×10^(4) s^(−1))without compromising color purity and exhibiting circularly polarized luminescence with|gPL|values at the 10^(−4) level.The solution-processed organic light-emitting diodes with po-PCP-tCzBNDiKTa show high maximum external quantum efficiency(EQE_(max))reaching 23%with a moderate efficiency roll-off,showing EQE of 18%and 9%at 100 and 1000 cd/m^(2.)展开更多
Polyhaloalkanes are broadly useful yet environmentally harmful stock chemicals,therefore the development of adsorbent materials with capacity and selectivity for polyhaloalkane vapors is highly desirable.Here we repor...Polyhaloalkanes are broadly useful yet environmentally harmful stock chemicals,therefore the development of adsorbent materials with capacity and selectivity for polyhaloalkane vapors is highly desirable.Here we report a novel macrocycle WreathArene,a fluorinated C;-symmetrical [1;]-paracyclophane.In the crysalline state,WreathArene features vip-adaptive polymorphism for polyhaloalkanes including chloroform,tribromomethane,1,1,2-trichloroethane,and 1,2-dibromoethane.Non-covalent C-halogen…πinteractions are observed in all of these host-vip structures.Based on these properties,the activated WreathArene crystals can be utilized as a selective and recyclable adsorbent for polyhaloalkane vapors with excellent capacity under user-friendly conditions.展开更多
An environmentally friendly and transition metal-free method for the preparation of chiral α- hydroxysilanes was developed. Enantioselective addition of a silicon nucleophile to aromatic aldehydes in water was achiev...An environmentally friendly and transition metal-free method for the preparation of chiral α- hydroxysilanes was developed. Enantioselective addition of a silicon nucleophile to aromatic aldehydes in water was achieved by using a new hydroxyl-functionalized chiral carbene as catalyst, affording the corresponding products in good yields and moderate enantioselectivities.展开更多
Thermally activated delayed fluorescence(TADF)exciplexes,constituted of donor-acceptor moieties,have garnered mounting interest because of their promising potential to obtain high-performance electroluminescent device...Thermally activated delayed fluorescence(TADF)exciplexes,constituted of donor-acceptor moieties,have garnered mounting interest because of their promising potential to obtain high-performance electroluminescent devices.However,the moderate reverse intersystem crossing(RISC)of current reported exciplex systems and the lack of clear molecular design concepts to improve this situation have distinctly hindered the further use of exciplexes in organic light-emitting diodes(OLEDs).Herein,we conduct an exploration of exciplex systems founded upon[2,2]paracyclophane(PCP)-containing donor molecules and a triazine acceptor,which exhibit very fast RISC processes with a rate constant(k_(RISC))up to 8.3×10^(6) s^(-1)benefiting from the efficient interactions between the donor and acceptor fragments induced by the peripheral spatial-blocking of PCP group.Utilizing these deep-blue exciplexes as hosts and a multiple resonance(MR)molecule as emitter,pure-blue narrowband OLEDs with CIE coordinates of(0.124,0.137),a full-width at half-maximum(FWHM)of 23 nm,and a high external quantum efficiency(EQE)of around 30%are accessed.This study paves the way for developing blue OLEDs using PCP-based exciplex materials with an enhanced RISC process.展开更多
文摘The through-space and through-bond interactions of molecular orbitals in [2,2] paracyclophane are studied by the approved MS-X. method with overlapping atomic-sphere. The calculation results show the through-space interactions are exponential flareout with increasing of the distance of two orbitals, and.both through-space interactions and through-bond interactions are sizable but those two interactions oppose each other causing the net splitting to be small. Transition-state procedure was used to calculate ionization potentials, the results are in agreement with the PE-spectra.
基金support of the Natural Science Foundation of China and Shandong Province(grant nos.21971149,92156007,21933003,ZR2019ZD45,and ZR2020KB005).
文摘Chiral[2.2]paracyclophane(PCP)is an intriguing prevalent scaffold widely utilized inπ-stacked polymers,luminescent materials,and asymmetric catalysis.However,current synthetic methods to access chiral PCP derivatives are still limited to physical separation and chemical or kinetic resolution.The direct desymmetric functionalization of nonsubstituted PCP has been a challenge since its discovery 70 years ago.Herein,we present a catalytic desymmetric dearomatization cyclopropanation reaction of PCP,providing rapid access to enantioenriched PCP cyclopropyl carboxylates with continuous tertiary/quaternary/quaternary chiral centers.The application of the chiral PCPs obtained has also been demonstrated by transformation to structurally novel C_(2) symmetric dirhodium catalysts.Of equal importance,detailed density functional theory calculations have been carried out to reveal the mechanism of this reaction.The key to this success is a structurally symmetric bulky C_(4) dirhodium catalyst:noncovalent interactions exist between substrates and catalysts,which form a cavity to host substrates,and mainly affect the regio-and enantioselectivity.
基金the China Scholarship Council(grant no.202106310038)for supportsupport from the China Postdoctoral Science Foundation(grant no.2022TQ0227)+2 种基金the Natural Science Foundation of Jiangsu Province,China(grant no.BK20230508)the China Scholarship Council(grant no.201906250199)support from the National Natural Science Foundation of China(grant no.52130304)the Suzhou Key Laboratory of Functional Nano&Soft Materials,the Collaborative Innovation Center of Suzhou Nano Science&Technology,the 111 Project.
文摘The development of circularly polarized multiresonant thermally activated delayed fluorescence materials with fast reverse intersystem crossing(RISC)process remains a challenge.Herein,we introduce high-lying excited states to assist the RISC process.Through arranging two known MR-TADF emitters tCzBN and DiKTa at the pseudo-ortho position of a chiral skeleton paracyclophane(PCP),the excitedstate density was increased.The proof-of-concept emitter po-PCP-tCzBN-DiKTa shows nearly three times higher kRISC(5.31×10^(4) s^(−1))than PCP-tCzBN(1.73×10^(4) s^(−1))without compromising color purity and exhibiting circularly polarized luminescence with|gPL|values at the 10^(−4) level.The solution-processed organic light-emitting diodes with po-PCP-tCzBNDiKTa show high maximum external quantum efficiency(EQE_(max))reaching 23%with a moderate efficiency roll-off,showing EQE of 18%and 9%at 100 and 1000 cd/m^(2.)
基金Financial support from the National Natural Science Foundation of China (Nos. 21672227, 21922113, 21988102, 22071257)Chinese Academy of Sciences (Nos. XDB17000000)+2 种基金the National Key Research and Development Program (No. 2017YFA0206903)K. C.Wong Education Foundationthe TIPC Director’s Fund。
文摘Polyhaloalkanes are broadly useful yet environmentally harmful stock chemicals,therefore the development of adsorbent materials with capacity and selectivity for polyhaloalkane vapors is highly desirable.Here we report a novel macrocycle WreathArene,a fluorinated C;-symmetrical [1;]-paracyclophane.In the crysalline state,WreathArene features vip-adaptive polymorphism for polyhaloalkanes including chloroform,tribromomethane,1,1,2-trichloroethane,and 1,2-dibromoethane.Non-covalent C-halogen…πinteractions are observed in all of these host-vip structures.Based on these properties,the activated WreathArene crystals can be utilized as a selective and recyclable adsorbent for polyhaloalkane vapors with excellent capacity under user-friendly conditions.
基金Financial support from the National Natural Science Foundation of China(Nos.21372144,81473085)Department of Science and Technology of Shandong Province
文摘An environmentally friendly and transition metal-free method for the preparation of chiral α- hydroxysilanes was developed. Enantioselective addition of a silicon nucleophile to aromatic aldehydes in water was achieved by using a new hydroxyl-functionalized chiral carbene as catalyst, affording the corresponding products in good yields and moderate enantioselectivities.
基金supported by the National Key R&D Program of China(2022YFE0109000)the National Natural Science Foundation of China(21975152,92256304,U23A20593)+1 种基金the China Postdoctoral Science Foundation(2022M722028)the Deutsche Forschungsgemeinschaft(DFG)under Germany’s Excellence Strategy(3DMM2O-EXC-2082/1-390761711)。
文摘Thermally activated delayed fluorescence(TADF)exciplexes,constituted of donor-acceptor moieties,have garnered mounting interest because of their promising potential to obtain high-performance electroluminescent devices.However,the moderate reverse intersystem crossing(RISC)of current reported exciplex systems and the lack of clear molecular design concepts to improve this situation have distinctly hindered the further use of exciplexes in organic light-emitting diodes(OLEDs).Herein,we conduct an exploration of exciplex systems founded upon[2,2]paracyclophane(PCP)-containing donor molecules and a triazine acceptor,which exhibit very fast RISC processes with a rate constant(k_(RISC))up to 8.3×10^(6) s^(-1)benefiting from the efficient interactions between the donor and acceptor fragments induced by the peripheral spatial-blocking of PCP group.Utilizing these deep-blue exciplexes as hosts and a multiple resonance(MR)molecule as emitter,pure-blue narrowband OLEDs with CIE coordinates of(0.124,0.137),a full-width at half-maximum(FWHM)of 23 nm,and a high external quantum efficiency(EQE)of around 30%are accessed.This study paves the way for developing blue OLEDs using PCP-based exciplex materials with an enhanced RISC process.
