Li J, Gryko D, Dabke RB, Diers JR, Bocian DF, Kuhr WG, Lindsey JS
Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, and Department of Chemistry, University of California, Riverside, California 92521-0403, USA.
J Org Chem. 2000 Nov 3;65(22):7379-90. doi: 10.1021/jo000490d.
The storage of multiple bits of information at the molecular level requires molecules with a large number of distinct oxidation states. Lanthanide triple-decker sandwich molecules employing porphyrins and phthalocyanines afford four cationic states and are very attractive for molecular information storage applications. Five triple-decker building blocks have been prepared of the type (phthalocyanine)Eu(phthalocyanine)Eu(porphyrin), each bearing one iodo, one ethyne, or one iodo and one ethyne group attached to the porphyrin unit. Two triple-decker building blocks with different oxidation potentials were derivatized with an S-acetylthiophenyl unit for attachment to an electroactive surface. To explore the preparation of arrays comprised of triple deckers, which may lead to the storage of a larger number of bits, two types of dyads of triple deckers were prepared. An ethyne-linked dyad of triple deckers bearing one S-acetylthiophenyl unit was prepared via repetitive Sonogashira couplings, and a butadiyne-linked dyad was prepared via a modified Glaser coupling. The triple deckers were characterized by absorption spectroscopy, laser-desorption mass spectrometry, and (1)H NMR spectroscopy. The thiol-derivatized triple deckers form self-assembled monolayers (SAMs) on gold via in situ cleavage of the thiol protecting group. The SAM of each array is electrochemically robust and exhibits three well-resolved, reversible oxidation waves. These electrochemical characteristics indicate that these types of molecules are well suited for storing multiple bits of information.
在分子水平上存储多位信息需要具有大量不同氧化态的分子。采用卟啉和酞菁的镧系元素三层夹心分子提供四种阳离子态，对分子信息存储应用极具吸引力。已经制备了五种类型为（酞菁）铕（酞菁）铕（卟啉）的三层结构单元，每个单元的卟啉单元上连接有一个碘、一个乙炔或一个碘和一个乙炔基团。用S - 乙酰硫苯基单元对两种具有不同氧化电位的三层结构单元进行衍生化，以便附着到电活性表面。为了探索由三层结构组成的阵列的制备方法（这可能会导致存储更多位的信息），制备了两种类型的三层结构二元体。通过重复的Sonogashira偶联反应制备了带有一个S - 乙酰硫苯基单元的乙炔连接的三层结构二元体，并通过改良的Glaser偶联反应制备了丁二炔连接的二元体。通过吸收光谱、激光解吸质谱和¹H NMR光谱对三层结构进行了表征。硫醇衍生化的三层结构通过硫醇保护基团的原位裂解在金表面形成自组装单分子层（SAMs）。每个阵列的SAM具有电化学稳定性，并且表现出三个分辨率良好的可逆氧化波。这些电化学特性表明这类分子非常适合存储多位信息。
