Air stable diradicaloid polycyclic aromatic hydrocarbon(PAH)materials possess unique electronic and magnetic properties for various applications.In general,long conjugated distances between two radical centers are req...Air stable diradicaloid polycyclic aromatic hydrocarbon(PAH)materials possess unique electronic and magnetic properties for various applications.In general,long conjugated distances between two radical centers are required to improve the air stability,thereby complicating the synthetic procedures.Herein,the chalcogen containing rubicenes(O-,S-,and Se-rubicenes)were systematically investigated to understand the chalcogen effects on chalcogen-rubicene physicochemical properties.Impressively,these rubicenes presented unprecedented diradical characterwithin one simple benzene ring and excellent air stabilities.Theirdiradicalcharacterweremanifested by single-crystal X-ray studies,variable-temperature nuclear magnetic resonance,and electron spin resonance.Furthermore,the nucleus independent chemical shifts andthe anisotropy of the induced currentdensity calculations revealed that the formation of diradical was caused by a pro-aromaticity driving force.Importantly,the diradical character of rubicenes are visualizedbyFractionalOccupationNumberWeighted Electron Density(FOD)plots,which present high NFOD values from 1.651 to 1.830.This contribution provided distinctive insights into the structure and property relationship of PAH diradicals.展开更多
The polarizability(α) and second hyperpolarizability(γ) were systemically investigated for singlet diradical complex involving X(X=B,Al,Ga) atom.The results show that both the α and γ can be effectively tune...The polarizability(α) and second hyperpolarizability(γ) were systemically investigated for singlet diradical complex involving X(X=B,Al,Ga) atom.The results show that both the α and γ can be effectively tuned by varying the distance R(between compound A and a water molecule) and acceptor atom X.The lone pair of electrons from the O atom of the water molecule entered into the vacant p orbital of atom X,which increased the diradical character and led to the increase of the α and γ values.Furthermore,the polarizable continuum model(PCM) was used to test the effects of H2O and CCl4 solvents on the α and γ values.Both the α and γ values of the studied diradical complex 1a(1b,1c) in H2O and CCl4 were uniformly enhanced.And the solvent effects of H2O on either α or γ were larger than those of CCl4.展开更多
Organic diradicaloids have unusual open-shell nature and properties and are promising materials for organic electronics,spintronics,energy storage and nonlinear optics.In this review,we focus on indeno-type organic di...Organic diradicaloids have unusual open-shell nature and properties and are promising materials for organic electronics,spintronics,energy storage and nonlinear optics.In this review,we focus on indeno-type organic diradicaloids and summarize their molecular design and synthesis,as well as topological structures,open-shell characters and diradical properties.The molecular systems are classified into indenofluorenes and diindenoacenes,indeno-based molecules with one-dimensional,two-dimensional and unique topological structures,and heterocyclic indeno-based molecules.By constructing these various topologicalπ-skeletons with tunable conjugation modes and variation of atomic composition,their key open-shell parameters,such as diradical characters and singlet-triplet energy gaps,along with the optical,electronic and magnetic properties,as well as stabilities are efficiently modulated.More attention may be paid to accurate computational analysis,rational design and synthesis,and novel functions of indeno-type diradicaloids,which will promote the development of radical chemistry and materials.展开更多
Benzo[1,2-c;4,5-cʹ]bis[1,2,5]thiadiazole(BBT)has intrinsic diradical character and herein it is used to construct organic near-infrared(NIR)dyes together with the aromatic porphyrin unit.Three BBT-porphyrin hybrid dye...Benzo[1,2-c;4,5-cʹ]bis[1,2,5]thiadiazole(BBT)has intrinsic diradical character and herein it is used to construct organic near-infrared(NIR)dyes together with the aromatic porphyrin unit.Three BBT-porphyrin hybrid dyes 1-3 with different linkage modes are synthesized by Pd-catalyzed Sonogashira crosscoupling between meso-ethynylene porphyrin units and monobromo-/dibromo-BBT,or through unexpected homocoupling between the BBT units.They all possess small open-shell diradical character and display intense NIR absorption in the range of 800-1000 nm.They also exhibit amphoteric redox behavior.BBT-based diradicaloids are thus good candidates for organic NIR dyes.展开更多
基金The work was supported by the NSFC(grant nos.51925306,21774130,and 21905277)National Key R&D Program of China(grant no.2018FYA 0305800)+2 种基金Key Research Program of the Chinese Academy of Sciences(grant no.XDPB08-2)the Strategic Priority Research Program of Chinese Academy of Sciences(grant no.XDB28000000)Fundamental Research Funds for the Central University.DFT results described in this short communication are obtained on the National Super-computing Center in Shenzhen(Shenzhen Cloud Computing Center).
文摘Air stable diradicaloid polycyclic aromatic hydrocarbon(PAH)materials possess unique electronic and magnetic properties for various applications.In general,long conjugated distances between two radical centers are required to improve the air stability,thereby complicating the synthetic procedures.Herein,the chalcogen containing rubicenes(O-,S-,and Se-rubicenes)were systematically investigated to understand the chalcogen effects on chalcogen-rubicene physicochemical properties.Impressively,these rubicenes presented unprecedented diradical characterwithin one simple benzene ring and excellent air stabilities.Theirdiradicalcharacterweremanifested by single-crystal X-ray studies,variable-temperature nuclear magnetic resonance,and electron spin resonance.Furthermore,the nucleus independent chemical shifts andthe anisotropy of the induced currentdensity calculations revealed that the formation of diradical was caused by a pro-aromaticity driving force.Importantly,the diradical character of rubicenes are visualizedbyFractionalOccupationNumberWeighted Electron Density(FOD)plots,which present high NFOD values from 1.651 to 1.830.This contribution provided distinctive insights into the structure and property relationship of PAH diradicals.
基金Supported by the National Natural Science Foundation of China(No.20873017)the Natural Science Foundation of Jilin Province,China(No.20101154)
文摘The polarizability(α) and second hyperpolarizability(γ) were systemically investigated for singlet diradical complex involving X(X=B,Al,Ga) atom.The results show that both the α and γ can be effectively tuned by varying the distance R(between compound A and a water molecule) and acceptor atom X.The lone pair of electrons from the O atom of the water molecule entered into the vacant p orbital of atom X,which increased the diradical character and led to the increase of the α and γ values.Furthermore,the polarizable continuum model(PCM) was used to test the effects of H2O and CCl4 solvents on the α and γ values.Both the α and γ values of the studied diradical complex 1a(1b,1c) in H2O and CCl4 were uniformly enhanced.And the solvent effects of H2O on either α or γ were larger than those of CCl4.
基金National Natural Science Foundation of China(No.22175074)Jilin Scientific and Technological Development Program,China(No.20220101054JC).
文摘Organic diradicaloids have unusual open-shell nature and properties and are promising materials for organic electronics,spintronics,energy storage and nonlinear optics.In this review,we focus on indeno-type organic diradicaloids and summarize their molecular design and synthesis,as well as topological structures,open-shell characters and diradical properties.The molecular systems are classified into indenofluorenes and diindenoacenes,indeno-based molecules with one-dimensional,two-dimensional and unique topological structures,and heterocyclic indeno-based molecules.By constructing these various topologicalπ-skeletons with tunable conjugation modes and variation of atomic composition,their key open-shell parameters,such as diradical characters and singlet-triplet energy gaps,along with the optical,electronic and magnetic properties,as well as stabilities are efficiently modulated.More attention may be paid to accurate computational analysis,rational design and synthesis,and novel functions of indeno-type diradicaloids,which will promote the development of radical chemistry and materials.
基金supported by NRF(NRF-NRFI05-2019-0005)MOE Tier 2 grant(MOE2018-T2-2-094).
文摘Benzo[1,2-c;4,5-cʹ]bis[1,2,5]thiadiazole(BBT)has intrinsic diradical character and herein it is used to construct organic near-infrared(NIR)dyes together with the aromatic porphyrin unit.Three BBT-porphyrin hybrid dyes 1-3 with different linkage modes are synthesized by Pd-catalyzed Sonogashira crosscoupling between meso-ethynylene porphyrin units and monobromo-/dibromo-BBT,or through unexpected homocoupling between the BBT units.They all possess small open-shell diradical character and display intense NIR absorption in the range of 800-1000 nm.They also exhibit amphoteric redox behavior.BBT-based diradicaloids are thus good candidates for organic NIR dyes.