The structural and thermodynamic （PCTAs） in the ideal gas state at 298.15 K and 1.013 properties of 75 polychlorinated thianthrenes ×10^5 Pa have been calculated at the B3LYP/6- 31G＊ level using Gaussian 98 pr...The structural and thermodynamic （PCTAs） in the ideal gas state at 298.15 K and 1.013 properties of 75 polychlorinated thianthrenes ×10^5 Pa have been calculated at the B3LYP/6- 31G＊ level using Gaussian 98 program. Based on the output data of Gaussian, the isodesmic reactions were designed to calculate standard enthalpy of formation （△fH^θ） and standard free energy of formation （△fH^θ） of PCTAs congeners. The relations of these thermodynamic parameters with the number and position of C1 atom substitution （Npcs） were discussed, and it was found that there exists high correlation between thermodynamic parameters （total energy （TE）, zero-point vibrational energy （ZPE）, thermal correction to energy （Eth）, heat capacity at constant volume （Cv^θ）, entropy （S^θ）, enthalpy （H^θ）, free energy （G^θ）, standard enthalpies of formation （△fH^θ） and standard Gibbs energies of formation （△fG^θ）） and Npcs. On the basis of the relative magnitude of their △fG^θ, the order of relative stability of PCTA congeners was theoretically proposed. In addition, the correlations between structural parameters and Npcs were also discussed. The good correlations were found between molecular average polarizability （α）, energy of the highest occupied molecular orbital （EHOMO）, molecular volume （Vm） and Npcs, and all R^2 values are larger than 0.95. Moreover, it was supposed that the isomer groups with higher toxicity should be Tri-CTA and TCTA.展开更多
Homogeneous formation of polychlorinated dibenzothiophenes/thianthrenes（PCDT/TAs）,sulfurated compounds analogous to polychlorinated dibenzo-p-dioxin/dibenzofurans（PCDD/Fs）, has been well-documented to occur via ra...Homogeneous formation of polychlorinated dibenzothiophenes/thianthrenes（PCDT/TAs）,sulfurated compounds analogous to polychlorinated dibenzo-p-dioxin/dibenzofurans（PCDD/Fs）, has been well-documented to occur via radical–radical coupling reactions from chlorinated thiophenol precursors. However, the current understanding of the formation mechanism of PCDT/TAs is exclusively limited to the inherent point of view that chlorothiophenoxy radicals act as the only required intermediates for PCDT/TAs. This study investigates reaction pathways for the formation of PCDT/TAs involving two new types of radical species, i.e., substituted phenyl radicals and substituted thiophenoxyl diradicals. Taking 2-chlorothiophenol（2-CTP） as a model compound for chlorothiophenols,we found that apart from the mostly discussed chlorothiophenoxy radicals, substituted phenyl radicals and substituted thiophenoxyl diradicals could also be readily formed via the reaction of 2-CTP with H radicals. Furthermore, direct self-and cross-coupling of these radicals can result in the formation of PCDT/TAs, including 1-monochlorothianthrene（1-MCTA）, 1,6-dichlorothianthrene（1,6-DCTA）, 4,6-dichlorodibenzothiophene（4,6-DCDT）and 1,6-dichlorodibenzothiophene（1,6-DCDT）. The pathways proposed in this work are proven to be both thermodynamically and kinetically favorable. Particularly, comparisons were made between the formation mechanisms of sulfurated and oxygenated dioxin systems from an energetic point view, showing that replacing oxygen with sulfur atoms greatly reduces the activation barriers of the rate-controlling steps involved in the PCDT/TA formation processes compared with those involved for PCDD/Fs. The calculated results in this work may improve our understanding of the formation mechanism of PCDT/TAs from chlorothiophenol precursors and should be informative to environmental scientists.展开更多
To gain insights into the potential of thianthrene(TA),its substituent effects were systematically studied on the room-temperature phosphorescence(RTP)properties,including the electron-donating and electron-withdrawin...To gain insights into the potential of thianthrene(TA),its substituent effects were systematically studied on the room-temperature phosphorescence(RTP)properties,including the electron-donating and electron-withdrawing substituents at 1-and 2-positions of TA,respectively.Both theoretical and experimental investigations show that the 2-position electron-withdrawing substituents greatly enhance RTP performance than the 1-position substituents,while the situation is exactly the opposite for electron-donating substituents.Compared with the 1-position substitution,the 2-position electron-withdrawing substituents induce the higher RTP radiation rate and lower non-radiation rate,in favor of the enhancement of RTP efficiency.Furthermore,the introduction of phenylene into the 2-position substitution greatly suppresses the non-radiation,resulting in the simultaneously improved RTP efficiency and elongated lifetime.Finally,using these RTP materials,the dynamically reversible operations of information(write-read-erase)are realized,as well as the encryption and time-dependent decryption demonstration.This work not only provides a better understanding of structure–property relationship on TA-based RTP materials,but also suggests an intramolecular structural modification strategy to improve the performance of pure organic RTP materials.展开更多
In order to develop pure organic single-molecule white-light emitters(SMWLE),the oxidation of thianthrene(TA)was performed on sulfur atoms at different degrees to tune room temperature phosphorescence(RTP)emission.Wit...In order to develop pure organic single-molecule white-light emitters(SMWLE),the oxidation of thianthrene(TA)was performed on sulfur atoms at different degrees to tune room temperature phosphorescence(RTP)emission.With increasing degrees of oxidation from 1OTA,2OTA,3OTA,to 4OTA,monomeric and aggregative RTP emission was gradually suppressed,due to the gradual disappearance of lone pair electrons on sulfur atoms.Among these compounds,monomers and aggregates of 1OTA demonstrated a better intensity match between fluorescence and RTP.展开更多
Deuterium(D),a stable and non-radioactive isotope of hydro-gen,is naturally present in the environment and is distinguishedfrom hydrogen by its greater mass.This mass difference resultsin a reduced stretching frequenc...Deuterium(D),a stable and non-radioactive isotope of hydro-gen,is naturally present in the environment and is distinguishedfrom hydrogen by its greater mass.This mass difference resultsin a reduced stretching frequency of the carbon-deuterium(C-D)bond,leading to lower ground state energy and higher bond dis-sociation energy compared to the carbon-hydrogen(C–H)bond.展开更多
Thioesters and their derivatives serve as prominently featured structural units in biological molecules.However,the lack of an adaptable and efficient synthetic method has hindered their widespread application.In term...Thioesters and their derivatives serve as prominently featured structural units in biological molecules.However,the lack of an adaptable and efficient synthetic method has hindered their widespread application.In terms of atom-and step-economy,there is an urgent need for an efficient strategy with a wider range of substrates compared to previous methods.Herein,we report a visible-light-driven synthesis of structurally diverse thioesters from aryl thianthrenium salts and carboxylic acids,using tetramethylthiourea as both sulfur source and potent photoreductant.This strategy utilizes aryl thianthrenium salts as novel electrophiles,which can be readily prepared via regioselective C–H thianthrenation of arenes.Mechanistic studies reveal that excited-state thiourea has strong reducing ability and can undergo a facile SET process with aryl thianthrenium salts.展开更多
Herein,we conceptualized a transient mediator approach that has the capability of para-selective C–H functionalization of monosubstituted aromatics.This approach is enabled by in situ generation of a versatile sulfon...Herein,we conceptualized a transient mediator approach that has the capability of para-selective C–H functionalization of monosubstituted aromatics.This approach is enabled by in situ generation of a versatile sulfonium salt via highly electrophilic phenoxathiine or thianthrene dication intermediate which can be readily generated from its sulfoxide with trifluoromethanesulfonic anhydride.Preliminary mechanistic study implied that the remarkable para selectivity might be related to the incredible electrophilicity of thianthrene dication intermediate.The versatility of this approach was demonstrated via paraborylation of various monosubstituted simple aromatics combining the sulfonium salt formation with further photocatalyzed transformation.展开更多
基金the National Natural Science Foundation of China(No.20737001 and 20477018)
文摘The structural and thermodynamic （PCTAs） in the ideal gas state at 298.15 K and 1.013 properties of 75 polychlorinated thianthrenes ×10^5 Pa have been calculated at the B3LYP/6- 31G＊ level using Gaussian 98 program. Based on the output data of Gaussian, the isodesmic reactions were designed to calculate standard enthalpy of formation （△fH^θ） and standard free energy of formation （△fH^θ） of PCTAs congeners. The relations of these thermodynamic parameters with the number and position of C1 atom substitution （Npcs） were discussed, and it was found that there exists high correlation between thermodynamic parameters （total energy （TE）, zero-point vibrational energy （ZPE）, thermal correction to energy （Eth）, heat capacity at constant volume （Cv^θ）, entropy （S^θ）, enthalpy （H^θ）, free energy （G^θ）, standard enthalpies of formation （△fH^θ） and standard Gibbs energies of formation （△fG^θ）） and Npcs. On the basis of the relative magnitude of their △fG^θ, the order of relative stability of PCTA congeners was theoretically proposed. In addition, the correlations between structural parameters and Npcs were also discussed. The good correlations were found between molecular average polarizability （α）, energy of the highest occupied molecular orbital （EHOMO）, molecular volume （Vm） and Npcs, and all R^2 values are larger than 0.95. Moreover, it was supposed that the isomer groups with higher toxicity should be Tri-CTA and TCTA.
基金supported by the National Natural Science Foundation (Nos. 21407167, 21621064, and 21607168)the Chinese Academy of Sciences (No. XDB14030500)
文摘Homogeneous formation of polychlorinated dibenzothiophenes/thianthrenes（PCDT/TAs）,sulfurated compounds analogous to polychlorinated dibenzo-p-dioxin/dibenzofurans（PCDD/Fs）, has been well-documented to occur via radical–radical coupling reactions from chlorinated thiophenol precursors. However, the current understanding of the formation mechanism of PCDT/TAs is exclusively limited to the inherent point of view that chlorothiophenoxy radicals act as the only required intermediates for PCDT/TAs. This study investigates reaction pathways for the formation of PCDT/TAs involving two new types of radical species, i.e., substituted phenyl radicals and substituted thiophenoxyl diradicals. Taking 2-chlorothiophenol（2-CTP） as a model compound for chlorothiophenols,we found that apart from the mostly discussed chlorothiophenoxy radicals, substituted phenyl radicals and substituted thiophenoxyl diradicals could also be readily formed via the reaction of 2-CTP with H radicals. Furthermore, direct self-and cross-coupling of these radicals can result in the formation of PCDT/TAs, including 1-monochlorothianthrene（1-MCTA）, 1,6-dichlorothianthrene（1,6-DCTA）, 4,6-dichlorodibenzothiophene（4,6-DCDT）and 1,6-dichlorodibenzothiophene（1,6-DCDT）. The pathways proposed in this work are proven to be both thermodynamically and kinetically favorable. Particularly, comparisons were made between the formation mechanisms of sulfurated and oxygenated dioxin systems from an energetic point view, showing that replacing oxygen with sulfur atoms greatly reduces the activation barriers of the rate-controlling steps involved in the PCDT/TA formation processes compared with those involved for PCDD/Fs. The calculated results in this work may improve our understanding of the formation mechanism of PCDT/TAs from chlorothiophenol precursors and should be informative to environmental scientists.
基金supported by the National Natural Science Foundation of China(52373183,52103209,and 52073117)the National Key Research and Development Program of China(No.2020YFA0714603)the China Postdoctoral Science Foundation(No.2024M761125).
文摘To gain insights into the potential of thianthrene(TA),its substituent effects were systematically studied on the room-temperature phosphorescence(RTP)properties,including the electron-donating and electron-withdrawing substituents at 1-and 2-positions of TA,respectively.Both theoretical and experimental investigations show that the 2-position electron-withdrawing substituents greatly enhance RTP performance than the 1-position substituents,while the situation is exactly the opposite for electron-donating substituents.Compared with the 1-position substitution,the 2-position electron-withdrawing substituents induce the higher RTP radiation rate and lower non-radiation rate,in favor of the enhancement of RTP efficiency.Furthermore,the introduction of phenylene into the 2-position substitution greatly suppresses the non-radiation,resulting in the simultaneously improved RTP efficiency and elongated lifetime.Finally,using these RTP materials,the dynamically reversible operations of information(write-read-erase)are realized,as well as the encryption and time-dependent decryption demonstration.This work not only provides a better understanding of structure–property relationship on TA-based RTP materials,but also suggests an intramolecular structural modification strategy to improve the performance of pure organic RTP materials.
基金supported by the National Natural Science Foundation of China(51873077,91833304,and 51803071)the National Basic Research Program of China(2016YFB0401001)+1 种基金the Postdoctoral Innovation Talent Support Project(BX20180121)the China Postdoctoral Science Foundation(2018M641767),and JLUSTIRT(2019TD-33).
文摘In order to develop pure organic single-molecule white-light emitters(SMWLE),the oxidation of thianthrene(TA)was performed on sulfur atoms at different degrees to tune room temperature phosphorescence(RTP)emission.With increasing degrees of oxidation from 1OTA,2OTA,3OTA,to 4OTA,monomeric and aggregative RTP emission was gradually suppressed,due to the gradual disappearance of lone pair electrons on sulfur atoms.Among these compounds,monomers and aggregates of 1OTA demonstrated a better intensity match between fluorescence and RTP.
基金Financial support from Science and Technology Innovation Program of Hunan Province(No.2022RC4044)。
文摘Deuterium(D),a stable and non-radioactive isotope of hydro-gen,is naturally present in the environment and is distinguishedfrom hydrogen by its greater mass.This mass difference resultsin a reduced stretching frequency of the carbon-deuterium(C-D)bond,leading to lower ground state energy and higher bond dis-sociation energy compared to the carbon-hydrogen(C–H)bond.
基金the National Natural Science Foundation of China(22271170)the Taishan Scholars Program from Shandong Province(Grant No.tsqn202408197)+1 种基金the Natural Science Foundation of Shandong Province(No.ZR2024QB154)the Scientific Research Foundation of Qingdao University of Science and Technology.
文摘Thioesters and their derivatives serve as prominently featured structural units in biological molecules.However,the lack of an adaptable and efficient synthetic method has hindered their widespread application.In terms of atom-and step-economy,there is an urgent need for an efficient strategy with a wider range of substrates compared to previous methods.Herein,we report a visible-light-driven synthesis of structurally diverse thioesters from aryl thianthrenium salts and carboxylic acids,using tetramethylthiourea as both sulfur source and potent photoreductant.This strategy utilizes aryl thianthrenium salts as novel electrophiles,which can be readily prepared via regioselective C–H thianthrenation of arenes.Mechanistic studies reveal that excited-state thiourea has strong reducing ability and can undergo a facile SET process with aryl thianthrenium salts.
基金supported by Shanghai Institute of Organic Chemistry,State Key Laboratory of Organometallic Chemistry,the National Natural Science Foundation of China(21890722,21702109,11811530637)the Natural Science Foundation of Tianjin City(18JCYBJC21400)the Fundamental Research Funds for the Central Universities(63191515,63196021,63191523).
文摘Herein,we conceptualized a transient mediator approach that has the capability of para-selective C–H functionalization of monosubstituted aromatics.This approach is enabled by in situ generation of a versatile sulfonium salt via highly electrophilic phenoxathiine or thianthrene dication intermediate which can be readily generated from its sulfoxide with trifluoromethanesulfonic anhydride.Preliminary mechanistic study implied that the remarkable para selectivity might be related to the incredible electrophilicity of thianthrene dication intermediate.The versatility of this approach was demonstrated via paraborylation of various monosubstituted simple aromatics combining the sulfonium salt formation with further photocatalyzed transformation.
