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三种同分异构的双苯并吩噻嗪材料的合成、理论计算及光物理性质
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作者 王鹤然 陈凯 +5 位作者 伏硕 王晧暄 袁加轩 胡星奕 许文娟 密保秀 《物理化学学报》 SCIE CAS CSCD 北大核心 2024年第1期48-56,共9页
吩噻嗪及其衍生物材料是一类重要的多环芳烃材料,在光电子领域有着广泛的应用。其中,基于苯并噻嗪材料的研究相对较少。在本文中,我们分别在吩噻嗪的1,2-、2,3-和3,4-位引入苯基,制备了三种同分异构的双苯并吩噻嗪化合物D-PTZa、D-PTZb... 吩噻嗪及其衍生物材料是一类重要的多环芳烃材料,在光电子领域有着广泛的应用。其中,基于苯并噻嗪材料的研究相对较少。在本文中,我们分别在吩噻嗪的1,2-、2,3-和3,4-位引入苯基,制备了三种同分异构的双苯并吩噻嗪化合物D-PTZa、D-PTZb和D-PTZc,研究了它们的构效关系,并与双吩噻嗪化合物(D-PTZ)进行了对比。研究发现,D-PTZb和D-PTZc的HOMO和LUMO分布与D-PTZ的类似;对于D-PTZa,其1,2-位引入的苯基与中间的苯环空间张力较大,造成空间结构极度扭曲,性质比较特殊。并苯的引入可以有效增加分子的共轭长度,使得最大吸收波长发生红移;在2,3-位引入苯基可以有效地稳定HOMO能级,使基于π→π*跃迁的能隙稍有增大,呈现蓝光发射,溶液的荧光量子产率为1.7%;而在3,4-位引入苯基使LUMO分布更加趋向于线型,从而使LUMO更加稳定,使基于π→π*跃迁的能隙降低,其最大发射峰位于520 nm处,呈现黄绿光发射,溶液荧光量子产率为13%。此外并入苯环之后,空间张力增大,化合物的分解温度降低。我们的分子设计和结构–性质关系的研究可以为设计新的吩噻嗪材料提供基础指导。 展开更多
关键词 苯并吩噻嗪 有机光电材料 密度泛函理论 空穴-电子分析 前线轨道分布 光物理性质
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Factors affecting poplar wetwood characteristics 被引量:1
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作者 Qilin Zhang xingyi hu +3 位作者 Qian hu Jiawei Yang Tianyu Zhao Kebing Du 《Journal of Forestry Research》 SCIE CAS CSCD 2023年第5期1615-1626,共12页
Wet wood is an abnormal phenomenon in growing trees,which adversely affects growth,subsequent wood processing and economic values of wood products.In this study,the influences of factors such as clones,afforestation m... Wet wood is an abnormal phenomenon in growing trees,which adversely affects growth,subsequent wood processing and economic values of wood products.In this study,the influences of factors such as clones,afforestation methods,site conditions and climate conditions on the characteristics of poplar wetwood were studied through field investigations in 27 clones from 48 sample plots in 28 counties.Results showed that the incidences of wetwood were almost 100%in all plots.Ratios of wetwood area among the48 plots differed from 15.1 to 90.2%.Wetwood area ratios,moisture contents and pH differed significantly between the 27 clones.Wetwood area ratios of the clones ranged from18.7 to 62.3%.Ratios of wetwood areas were positively correlated with wet wood moisture content and pH,tree age,and negatively correlated with pH of sap wood.The repeatability of wet wood area ratios was 0.52,moderately controlled by genetics.Wetwood moisture content and pH were highly controlled by genetics,indicated by the repeatability of 0.91 and 0.89,respectively.There were significant differences in wetwood area ratios,moisture content and pH between different site conditions,afforestation methods,and geographical regions.Sloping land had the lowest wetwood area ratios and moisture content among four types of sites.Afforestation by direct seeding and rooted cuttings had the lowest wetwood area ratios and moisture content,respectively.In the three geographical regions,the Yellow River Basin had the lowest wetwood values of all three factors. 展开更多
关键词 POPLAR WETWOOD CLONES Site conditions Afforestation methods
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