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分子中含-CH_2O-桥键液晶化合物的结构和相变间关系 被引量:3
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作者 李瑞军 任国度 《郑州大学学报(自然科学版)》 CAS 1999年第1期84-87,共4页
合成出一组分子中含-CH2O-桥键的4-(trans-4″-n-烷基环已基甲氧基)-4′-氰基联苯液晶化合物,经DSC测定了其相变温度范围,研究发现液晶分子中的吸电子端基有助于化合物呈现液晶相及增加液晶相的热稳定性;... 合成出一组分子中含-CH2O-桥键的4-(trans-4″-n-烷基环已基甲氧基)-4′-氰基联苯液晶化合物,经DSC测定了其相变温度范围,研究发现液晶分子中的吸电子端基有助于化合物呈现液晶相及增加液晶相的热稳定性;随分子中烷基链长的增加,有助于液晶呈现近晶相但液晶相的热稳定性降低; 展开更多
关键词 结构 DSC 液晶化合物 相变 热稳定性 氰基联苯
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2,3,5,6-四氟苯甲腈的合成 被引量:2
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作者 何光文 陈宏博 戎娟 《辽东学院学报(自然科学版)》 CAS 2008年第2期66-68,共3页
以2,3,5,6-四氟苯甲酸为原料,经过酰氯制得酰胺后,再经脱水制得2,3,5,6-四氟苯甲腈,总收率61.8%,产品含量98%,这是一条最有望工业化的合成路线。
关键词 2 3 5 6-四氟苯甲酸 2 3 5 6-四氟苯甲腈 脱水
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Cobalt-catalyzed redox-neutral synthesis of isoquinolines: C–H activation assisted by an oxidizing N–S bond 被引量:1
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作者 王芬 王强 +1 位作者 包明 李兴伟 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第8期1423-1430,共8页
A redox‐neutral avenue to access isoquinolines has been realized by a Co(III)‐catalyzed C–H activa‐tion process. Starting from readily available N‐sulfinyl imine substrates and alkynes, the reaction occurred vi... A redox‐neutral avenue to access isoquinolines has been realized by a Co(III)‐catalyzed C–H activa‐tion process. Starting from readily available N‐sulfinyl imine substrates and alkynes, the reaction occurred via N–S cleavage with broad substrate scope and functional group compatibility in the presence of cost‐effective cobalt catalysts. 展开更多
关键词 Cobalt(III) catalyst Carbon-hydrogen activation N-sulfinyl imine ISOQUINOLINE
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Small-sized cuprous oxide species on silica boost acrolein formation via selective oxidation of propylene 被引量:2
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作者 Ling-Ling Guo Jing Yu +6 位作者 Wei-Wei Wang Jia-Xu Liu Hong-Chen Guo Chao Ma Chun-Jiang Jia Jun-Xiang Chen Rui Si 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2021年第2期320-333,共14页
Oxide-supported copper-containing materials have attracted considerable research attention as promising candidates for acrolein formation.Nevertheless,the elucidation of the structure-performance relationships for the... Oxide-supported copper-containing materials have attracted considerable research attention as promising candidates for acrolein formation.Nevertheless,the elucidation of the structure-performance relationships for these systems remains a scientific challenge.In this work,copper oxide clusters deposited on a high-surface-area silica support were synthesized via a deposition-precipitation approach and exhibited remarkable catalytic reactivity(up to 25.5%conversion and 66.8%selectivity)in the propylene-selective oxidation of acrolein at 300℃.Aberration-corrected high-angle annular dark-field scanning transmission electron microscopy combined with X-ray absorption fine structure measurements of the catalyst before and after the reaction confirmed the transformation of the small-sized copper oxide(CuO)clusters into cuprous oxide(Cu2O)clusters.With the aid of in situ X-ray diffraction and in situ dual beam Fourier transform infrared spectroscopy(DB-FTIR),the allyl intermediate(CH2=CHCH2*)was clearly observed,along with the as-formed Cu2O species.The intermediate can react with oxygen atoms from neighboring Cu2O species to form acrolein during the catalytic process,and the small-sized Cu2O clusters play a crucial role in the generation of acrolein via the selective oxidation of propylene. 展开更多
关键词 Propylene selective oxidation Cuprous oxide cluster Acrolein formation Active species In situ characterization
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