摘要
将性能优良的介晶单元氰基联苯基元引入到四硫富瓦烯(TTF)的外围,成功合成了3种新型的液晶化合物.通过核磁共振波谱(NMR)、傅里叶变换红外光谱(FTIR)和基质辅助激光解吸电离飞行时间质谱(MALDI-TOF-MS)对其结构进行了表征.利用示差扫描量热分析(DSC)、热台偏光显微镜(HS-POM)和小角X射线散射(SAXS)实验对3种化合物的液晶相态进行了研究.结果表明:合成的3种化合物在宽的温度范围呈现单一液晶相,在冷却过程中并没有出现结晶现象,而是转化为玻璃态.间隔基长度的变化对液晶化合物相态的影响显著,间隔基较短的化合物呈近晶A相(Sm A),而具有较长间隔基的化合物(1c)呈现六方柱状相.采用密度泛函(DFT)方法计算了化合物1a的电子结构和前线分子轨道密度分布,化合物1a的HOMO轨道上的电子云密度集中在TTF上,LUMO集中在氰基联苯上,说明此类液晶分子为典型的D-σ-A分子.
Mesocrystalline cyanodiphenyl moiety was introduced to the periphery of tetrathiofuvalene( TTF) to successfully synthesize three new liquid crystal compounds. Their structures were fully characterized by means of NMR,FTIR and MALDI-TOF-MS methods. The liquid crystal phase state of the compounds was studied by differential scanning calorimetry( DSC),hot stage polarizing microscopy( HS-POM) and small angle X-ray scattering( SAXS) experiment. The results demonstrated that the synthesized compounds in the wide range of temperature displayed a single liquid crystal phase and in the cooling process did not appear crystallization phenomenon,but transformed into the glass state. The change of linker length had significant influence on the phase state of liquid crystal compounds. The results illustrated that compound with shorter linker represented smectic A phase( Sm A),while compound with longer spacer( 1 c) presented hexagonal columnar mesophase.The density functional theory( DFT) was used to calculate the electron structure and the electron density distribution of molecular frontier orbital of compound 1 a. The results showed that the electron cloud density of the HOMO orbital of compound 1 a was concentrated on TTF,and that of LUMO was concentrated on cyanobenzene,indicating that such liquid crystal molecules were typical D-σ-A molecules.
作者
魏福志
冯微
夏艳
李东风
侯瑞斌
WEI Fuzhi;FENG Wei;XIA Yan;LI Dongfeng;HOU Ruibin(College of Chemistry and Life Science;Advanced Institute of Materials Science, Changchun University of Technology, Changchun 130012, China;China-Japan Union Hospital of Jilin University, Changehun 130033, China)
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
2018年第7期1549-1553,共5页
Chemical Journal of Chinese Universities
基金
国家自然科学基金(批准号:21442004)
吉林省教育厅项目(批准号:2016320)资助