Design, synthesis, and characterization of prototypical multistate counters in three distinct architecturesElectronic supplementary information (ESI) available: 1H NMR and 13C NMR spectra for each dipyrromethane; absorption, LD-MS, and 1H NMR spectra for each porphyrin and each triple decker; absorption and LD-MS spectra for each triple-decker dyad. See http://www.rsc.org/suppdata/jm/b1/b108520d/
作者:Karl-Heinz Schweikart、Vladimir L. Malinovskii、James R. Diers、Amir A. Yasseri、David F. Bocian、Werner G. Kuhr、Jonathan S. Lindsey
DOI:10.1039/b108520d
日期:2002.3.21
The storage of multiple bits of information in distinct molecular oxidation states is anticipated to afford extraordinarily high memory densities. Among redox-active molecules, lanthanide porphyrinic triple-decker complexes are attractive candidates for such molecular information storage elements because they provide at least four cationic states over a modest potential range. Our approach toward a molecular multistate counter involves covalently linking two triple deckers with interleaving oxidation potentials to achieve a commensurate increase in the number of oxidation states within a single dyad. We report the design and synthesis of five dyads comprised of triple-decker complexes of the form (Pc)Ln(Pc)Ln(Por) or (Por1)Ln(Pc)Ln(Por2), where Pc = phthalocyaninato, Por = porphyrinato, and Ln = Ce or Eu. The dyads were prepared in a modular building-block fashion by Pd-mediated
coupling of an iodophenyl-triple decker and an ethynylphenyl-triple decker. The different dyad architectures examined include a vertical architecture with one linker (V1), a horizontal architecture with one linker (H1), and a horizontal architecture with two linkers (H2). In each dyad, one or two S-acetylthiomethyl groups incorporated on the porphyrinic moiety of the triple decker enables attachment to an electroactive surface viain situ cleavage of the protected thiol linker(s). Three dyads (Dyad1–3) have the V1 architecture but different compositions of triple deckers; three dyads (Dyad3–5) have identical composition but different architectures (V1, H1, H2) for comparison of the properties in self-assembled monolayers (SAMs) on gold. The SAM of each dyad exhibits robust reversible electrochemical behavior; the redox waves are essentially the sum of the
waves of the component triple deckers. In contrast, mixtures of the component triple decker monomers form poor quality SAMs with inferior electrochemical characteristics. Accordingly, all three dyad architectures are viable constructs for assembling a multistate counter.
以不同的分子氧化态存储多位信息预计将提供极高的存储密度。在氧化还原活性分子中,镧系卟啉三层络合物是此类分子信息存储元件的有吸引力的候选者,因为它们在适度的电势范围内提供至少四种阳离子状态。我们的分子多态计数器方法涉及将两个具有交错氧化电位的三层结构共价连接,以实现单个二联体内氧化态数量的相应增加。我们报告了由 (Pc)Ln(Pc)Ln(Por) 或 (Por1)Ln(Pc)Ln(Por2) 形式的三层配合物组成的五对二元体的设计和合成,其中 Pc = 酞菁基,Por = 卟啉基,且 Ln = Ce 或 Eu。这对二元组是通过 Pd 介导的模块化构建块方式制备的
碘苯基三层结构和乙炔基苯基三层结构的偶联。所检查的不同二元体系结构包括具有一个链接器的垂直体系结构 (V1)、具有一个链接器的水平体系结构 (H1) 和具有两个链接器的水平体系结构 (H2)。在每一对中,掺入三层的卟啉部分上的一个或两个S-乙酰硫甲基能够通过受保护的硫醇连接体的原位裂解而附着到电活性表面。三个二元组(Dyad1-3)具有 V1 架构,但三层甲板的组成不同;三个二元体 (Dyad3-5) 具有相同的组成但不同的结构 (V1、H1、H2),用于比较金上自组装单层 (SAM) 的特性。每个二元体的 SAM 均表现出强大的可逆电化学行为;氧化还原波本质上是
组件三层甲板的波浪。相比之下,三层单体的混合物形成的 SAM 质量较差,电化学特性较差。因此,所有三种二元架构都是用于组装多状态计数器的可行构造。