Metal Complexes:Novel Chiral Dopants with High Helical Twisting Power in Liquid Crystals

来源 :复旦学报(自然科学版) | 被引量 : 0次 | 上传用户:liongliong496
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
1 Introduction A particularly efficient and elegant route to chiral mesophases is based on the addition of small amounts of an enantiomerically pure dopant to a nematic phase so that the latter is converted into a cholesteric phase(See Fig.1).Fig.1 A nematic phase is converted into a cholesteric phase Fig.2 Bis-chelated imine-alkoxy-titanium complexes2 ExperimetalBis-chelated imine-alkoxy-titanium complexes like 1 and 2 (Fig.2) have been synthesizedstarting from triphenyl-substituted aminoethanols, The octahedral complexes are obtained as pure diastereomers and enantiomers, and their configuration has been assigned by crystal structure analyses andCD spectroscopy. In various commercial nematic phases, they exhibit exceptionally high helical twisting power (HTP). Indeed, the highest HTP values reported sofar, including a “record” of 740 μm-1 has been reported with complex 2 (X=OEt)[1]. The application of the novel dopants seemsto meet commercial interest[2].The same type of chiral ligands also serve to synthesize boron complexes that exhibit significant HTP as well. Remarkably, the boron atom becomes a stereogenic center with a stable configuration. 1 Introduction A particularly efficient and elegant route to chiral mesophases is based on the addition of small amounts of an enantiomerically pure dopant to a nematic phase so that the latter is converted into a cholesteric phase (See Fig. 1). FIG.1 A nematic The phase is converted into a cholesteric phase Fig. 2 Bis-chelated imine-alkoxy-titanium complexes 2 ExperimetalBis-chelated imine-alkoxy-titanium complexes like 1 and 2 (Fig.2) have been synthesized from triphenyl-substituted aminoethanols, The octahedral complexes are obtained as pure diastereomers and enantiomers, and their configuration has been assigned by crystal structure analyzes and CD spectroscopy. Indeed, the highest HTP values ​​reported sofar, including a “ record ”of 740 μm-1 has been reported with complex 2 (X = OEt) [1]. The application of the novel dopants seem to meet commercial interest [2]. The same type of chir al ligands also serve to synthesize boron complexes that exhibit significant HTP as well. Remarkably, the boron atom becomes a stereogenic center with a stable configuration.
其他文献
会议
1 Results Biotransformations are enzyme- and whole cell-catalysed conversions of non-natural substrates to products.They are important tools in organic synthes
会议
会议
1 Results The reaction mechanisms of the atomic layer deposition (ALD) processes used for thin-film growth have been characterized by a combination of surface
会议
目的:探讨棕榈酸(PA)对小鼠骨髓来源巨噬细胞(BMDM)极化的影响及机制.方法:提取BALB/c小鼠骨髓细胞,于含有10%胎牛血清和20 ng/ml GM-CSF的DMEM低糖培养基中诱导7d后得到BMDM,
会议
国土资源部将对省级以下开发区从严审核 国土资源部近日表示,土地市场治理整顿特别是开发区清理整顿已进入关键阶段。国土资源部将进一步加强省级以下开发区清理整顿力度,确
1 Results Heterostructures,based on ternary CuInS(Se2) chalcogenides and related binary compounds (Cu2-xCh,CuCh,In2Ch3 and InCh; Ch=S,Se) are considered appear
会议
会议
会议