Effects of Auxiliary Ligands of Pd(II) Dimers on Induction of Chiral Nematic Phases: Chirality Inversion and Photo-responsive Structural Change
Effects of Auxiliary Ligands of Pd(II) Dimers on Induction of Chiral Nematic Phases: Chirality Inversion and Photo-responsive Structural Change
复制标题
Pd(II) 二聚体辅助配体对手性向列相诱导的影响：手性反转和光响应结构变化
DOI：
10.1039/c4dt02812k
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Akihiko Yamagishi and Hisako Sato*
中科院分区：
文献类型：
--
作者：
Kenji Tamura;Jun Yoshida;Takafumi Kitazawa;Masahiro Taniguchi;Akihiko Yamagishi and Hisako Sato*
制备了双核方形平面钯 (II) 配合物 [{Pd(II)La}2(baet)]（La− = β-二酮和 baet2− = 1,2-二乙酰基-1,2-双（3-甲基丁酰基）乙酯基）并用作手性掺杂剂以诱导手性向列相。以下β-二酮用作LaH：戊烷-2,4-二酮(acacH)、二苯甲酰甲烷(dbmH)、二-4-壬氧基苯甲酰甲烷(C9-dbmH)和3-[4'-(4''-(辛氧基)苯基偶氮)苯基]-2,4-二酮(C8-azoacacH)。当对映体掺杂到向列液晶中时，它们会诱导出螺旋扭转力 (HTP) 为 5–50 μm−1 的手性向列相。特别是，掺杂[{Pd(II)(C8-azoacac)}2(baet)]的样品在350 nm和460 nm交替照射下表现出圆二色光谱的可逆变化。这意味着 HTP 响应于配位的 C8-azoacac 配体的顺反异构化而发生可逆变化。
Dinuclear square planar palladium(II) complexes, [{Pd(II)La}2(baet)] (La− = β-diketonato and baet2− = 1,2-diacetyl-1,2-bis(3-methylbutanoyl)ethanato), were prepared and used as chiral dopants to induce chiral nematic phases. The following β-diketones were used as LaH: pentane-2,4-dione (acacH), dibenzoylmethane (dbmH), di-4-nonyloxybenzoylmethane (C9-dbmH) and 3-[4′-(4′′-(octyloxy)phenylazo)phenyl]-2,4-dione (C8-azoacacH). When the enantiomers were doped in a nematic liquid crystal, they induced a chiral nematic phase with a helical twisting power (HTP) of 5–50 μm−1. In particular, the sample doped with [{Pd(II)(C8-azoacac)}2(baet)] exhibited a reversible change of the circular dichroism spectrum under alternate irradiation at 350 nm and 460 nm. It implied that the HTP changed reversibly in response to the cis–trans isomerization of the coordinated C8-azoacac ligand.