端基含36个4-硝基偶氮苯介晶基元的二代树状碳硅烷的液晶性研究

液晶树状物的液晶相态分别为SA相、SC相、SC^*相、向列相、胆甾相、盘状相、立方相和群聚向列相,而SE相液晶树状物尚未见报道,本文报道含吸电性端基(硝基)偶氮苯介晶基元二代树状物(D2)的液晶行为。     

端基含108个己氧基偶氮苯介晶基元三代树状碳硅烷液晶研究

用发散法合成以四碳硅烷为核心,周边含108个己氧基偶氮苯介晶基元(M3)端基的三代树状碳硅烷(D3)液晶,并用元素分析、核磁共振、激光解吸电离飞行时间质谱、红外光谱、紫外光谱、偏光显微镜、差示扫描量热(DSC)和X射线衍射法(WAXD)进行表征.D3为向列相液晶,与M3相同,三代(D3)、二代(D2)和一代(D1)树状物的相态由介晶基元的相态决定.D3的液晶态相行为是K79N136I132N,D3的熔点比M3的低19℃,D3的清亮点比M3的增加16℃,D3液晶态温区比M3宽35℃.     

一代树状碳硅烷液晶研究-端基含12个4-硝基偶氮苯介晶基元

用发散法合成了以四碳硅烷为核心，周边含12个4-硝基偶氮苯介晶基元（M5） 端基的新的一代树状碳硅烷（D1）液晶，并用元素分析、核磁共振、基质辅助激光 解吸离子化飞行时间质谱（MALDI-TOF-MS）、红外、紫外、偏光显微镜、差示扫描 量热（DSC）和X射线衍射法（WAXD）表征。介晶基元化合物（M5）显示向列相，树 状物D1显示胆甾相和S_E相。D1的液晶相相行为是K70Ch188I185Ch58S_E-48K。     

二代树状碳硅烷液晶研究I.端基含36个丁氧基偶氮苯介晶基元

用发散法合成周边含36个丁氧基偶氮苯介晶基元（M5）端基新的二代树状碳硅 烷液晶（D_2），并用元素分析，氢谱，激光质谱，红外，紫外，偏光显微镜，DSC和WAXD法表 征D2为向列相，与M5相同，二代树状物相态由介晶基定．D2液晶态相行为是 K85N107I103N69K，其熔点比M5降低27-41℃，清亮点比M5降低17-18宽10-23℃．二 代碳硅烷（D2）与一代碳硅烷（D1）相比熔点增加2-3℃，清亮点降低26-29℃，液 晶态温区减少℃．在二代树状物中观察到S＝＋3／2的高强向错．     

二代树状碳硅烷液晶研究Ⅰ.端基含36个丁氧基偶氮苯介晶基元

用发散法合成周边含36个丁氧基偶氮苯介晶基元(M5)端基新的二代树状碳硅烷液晶(D2),并用元素分析,氢谱,激光质谱,红外,紫外,偏光显微镜,DSC和WAXD法表征.D2为向列相,与M5相同,二代树状物相态由介晶基元相态决定.D2液晶态相行为是K85N107I103N69K,其熔点比M5降低27～41℃,清亮点比M5降低17～18℃,液晶态温区比M5加宽10～23℃.二代碳硅烷(D2)与一代碳硅烷(D1)相比熔点增加2～3℃,清亮点降低26～29℃,液晶态温区减少29～31℃.在二代树状物中观察到S=+3/2的高强向错.     

二代树状碳硅烷液晶研究I.端基含36个丁氧基偶氮苯介晶基元

用发散法合成周边含36个丁氧基偶氮苯介晶基元（M5）端基新的二代树状碳硅 烷液晶（D_2），并用元素分析，氢谱，激光质谱，红外，紫外，偏光显微镜，DSC和WAXD法表 征D2为向列相，与M5相同，二代树状物相态由介晶基定．D2液晶态相行为是 K85N107I103N69K，其熔点比M5降低27-41℃，清亮点比M5降低17-18宽10-23℃．二 代碳硅烷（D2）与一代碳硅烷（D1）相比熔点增加2-3℃，清亮点降低26-29℃，液 晶态温区减少℃．在二代树状物中观察到S＝＋3／2的高强向错．     

基于季戊四醇的三代硅碳烷液晶树状物研究

用发散法合成了季戊四醇-四烯丙基醚为核、周边含硝基偶氮苯介晶基元(M-NO₂)端基的新型三代硅碳烷液晶树状物PCSi-3G-NO₂, 并利用元素分析、红外光谱(IR)、核磁共振(NMR)、偏光显微镜(POM)、差示扫描量热法(DSC)和X射线衍射(XRD)进行表征. PCSi-3G-NO₂显示胆甾相和近晶S_E相, 其液晶相行为是K57S_E115I100Ch80S_E53K. 而对应的介晶基元M-NO₂显示向列相, 二者在熔点、清亮点和液晶态温区等方面差别较大.     

A Novel Pentaerythritol-based Carbosilane Liquid Crystalline Dendrimer Containing 12 Nitroazobenzene Groups on the Periphery

A novel liquid crystalline dendrimer with peripheral mesogenic units was successfully prepared. Azo-reaction and Williamson synthesis were employed in the preparation of the mesogenic unit 4-[4-(6-hydroxyhexyloxy)-phenylazo]nitrobenzene (M-NO2). A terminal Si-Cl functional carbosilane dendrimer based on pentaerythritol was used as dendritic scaffold and subsequently functionalized with the aforementioned groups. Investigation of the liquid crystalline properties of the mesogen-functionalized dendrimer PCSi-IG-NO2 by polarizing optical microscopy, DSC, and X-ray diffraction showed that it exhibits smectic E (SE) phase, different from the corresponding mesogenic unit, which shows nematic phase. Furthermore, the temperatures of both the melting point and the clearing point of the mesogen-functionalized dendrimer decrease, and the temperature region of the SE phase is wider than that of the nematic phase.     

三代树状碳硅烷液晶研究——端基含丁氧基偶氮苯介晶基元

用发散法合成周边含丁氧基偶氮苯介晶基元(M5)端基新的三代树状碳硅烷(D3) 液晶,并用元素分析,核磁共振,激光解吸电离飞行时间质谱(MALDI-TOF-MS),红外、 紫外、偏光显微镜、差示扫描量热（DSC）和广角X射线衍射（WAXD）表征，D3为向 列相与M5相同，树状物相态由介晶基元相态决定，D3相行为；K79N1261116N，D3熔 点比M5降低33℃，D3清亮点比M5增加2℃，D3液晶态温区比M5加宽35℃。     

基于1,6-己二醇的哑铃型树状大分子

Novel carbosilane dendrimers based on 1,6-hexanediol were prepared by divergent approach. Using 1,6-hexanediol-based diallyl ether as the core molecule, the dendrimers were prepared to the third generation with 54 allyl groups on the periphery by alternate hydrosilylation-allylation reactions.     

Pentaerythritol-based Carbosilane Dendrimers

A series of novel pentaerythritol-based carbosilane dendrimers have been synthesized. Using pentaerythritol-based tetraallyl ether as core molecule, the dendrimers have been prepared up to the third generation with I08 allyl groups on the periphery by alternate allylation-hydrosilylation approach.     

一代树状碳硅烷液晶研究－端基含12个丁氧基偶氮苯介晶基元

用发散法合成周边含12个丁氧基偶氮苯介晶基元（M5）端基新的一代树状碳硅 烷（D1）。并用元素分析、核磁共振、激光解吸电离飞行时间质谱、红外、紫外、 偏光显微镜、差示扫描量热（DSC）和广角X射线衍射（WAXD）表征。D1为向列相与 M5相同，树状物相态由介晶基元相态决定，D1相行为：K82N133I132N67K，D1熔点 比M5降低30－43℃，D1清亮点比M5增加9－11℃，D1介晶相区比M5加宽39－54℃， 观察到8条黑刷的树状物的高强向错（S＝＋2），D1清亮焓值略低于通常液晶n-i相 变清亮焓值，原因是枝化的树状物核心不易完全变形为液晶态的各向异性结构。     

Synthesis of Novel Carbosilane Dendrimers Based on Pentaerythritol

Novel pentaerythritol-based carbosilane dendrimers centered at carbon have been synthesised. Starting from tetraallyl ether based upon pentaerythritol as the core molecule, a succession of alternate Pt-catalyzed hydrosilylation of allyl groups with HSiC13 and allylations of SiC1 groups thus introduced with CH2=CHCH2MgBr in THF provided a divergent synthesis of three generations of carbosilane dendrimers in which the Si atoms are linked by CH2CH2CH2 groups. The reaction conditions for hydrosilylation must be well controlled. After purification by chromatography on silica gel pure products for each generation were obtained. The IR, ^1H and ^13C NMR spectra and elemental analysis data are consistent with the proposed structures. The molecular weights of the resulting carbosilne dendrimers have been determined by vapor pressure osmometry.     

碳硅烷树枝状化合物的功能化研究

本文根据碳硅烷树枝状化合物功能基的种类及反应特性,介绍了有关含硅树枝状化合物的功能化的方法,并对功能化含硅树枝状化合物的用途做了相应评述.     

The Preparation of the Carbosilane Dendrimers with Pentafluorophenyl Groups

Dendrimers as intriguing macromolecules possess potential in phase transfer catalysis, hosts-guest chemistry, controlled release drugs or might serve as recyclable extracting agents1,2,3. The fluorine-containing dendrimers can be used as low surface-energ…