A series of novel β-diketone ligands bearing alkyloxyphenyl R = C6H4OCnH2n+1 and pyridyl substituents at 1 and 3 positions of the β-diketone core [HLR(n)py] have been prepared and structurally characterized. The corresponding β-diketonate complexes [Pd(κ2-LR(n)py)2] were isolated as a mixture of cis and trans isomers each of them exhibiting the ligand in a NO- or OO-bidentate coordinative mode which were established by multinuclear NMR studies (1H, 13C and 15N). However none of those characteristics were determining to achieve liquid-crystalline properties on the new complexes. By contrast reactions of the aforementioned ligands [HLR(n)py] or those containing the pyridiniumyl substituent [HLR(n)pyH]+ towards the allylâpalladium fragment were successful to afford ionic metallomesogenic materials isolated as PF6 salts of [Pd(η3-C3H5)(κ2-HLR(n)py)][PF6] (I) and [Pd(η3-C3H5)(κ2-LR(n)pyH)][PF6] (II) types. Structural characterization and mesomorphic properties were established by multinuclear NMR and the use of DSC and POM techniques. In complexes I and II the corresponding β-diketone ligands were coordinated as neutral bidentate NO-donor or zwitterionicOO-donor systems, respectively. Complexes of type II exhibit a range of the SmC mesophases significantly greater than that found in the type I.
一系列新型
β-二酮配体,其在
β-二酮核心的1和3位置带有烷氧基苯基(R=C6H4OCnH2n+1)和
吡啶基取代基[HLR(n)py],已制备并结构表征。相应的
β-二酮酸盐配合物[Pd(κ2-LR(n)py)2]以顺反异构体混合物形式分离出来,每个异构体都表现出
配体在NO-或OO-双齿配位模式,这是通过多核NMR研究(1H、13C和15N)确定的。然而,这些特征都不是新配合物具有液晶特性的决定因素。相比之下,上述
配体[HLR(n)py]或含有
吡啶盐基取代基的
配体[HLR(n)pyH]+与烯丙基-
钯片段反应成功得到了离子型
金属介晶材料,分离为[Pd(η3-
C3H5)(κ2-HLR(n)py)][PF6](I)和[Pd(η3- )(κ2-LR(n)pyH)][PF6](II)类型的PF6盐。结构表征和介晶性质是通过多核NMR以及使用
DSC和POM技术确定的。在配合物I和II中,相应的
β-二酮配体分别作为中性双齿NO供体或两性离子OO供体系统配位。II型配合物显示出比I型更广泛的SmC介晶相。