Universität Würzburg, Institut für Organische Chemie and Röntgen Research Center for Complex Material Systems, Am Hubland, 97074 Würzburg, Germany.
Chemistry. 2011 May 2;17(19):5300-10. doi: 10.1002/chem.201002659. Epub 2011 Apr 4.
A chlorophyll derivative with a central zinc ion, a methoxy functionality at its 3(1)-position, and functionalized with a second-generation dendron (3,4-3,4,5)12G2-CH(2)OH at its 17(2)-position was synthesized starting from natural chlorophyll a (Chl a). This compound exhibits liquid crystalline (LC) behavior and its mesomorphic properties have been characterized by differential scanning calorimetry (DSC), polarisation optical microscopy (POM), powder X-ray diffraction (XRD), and scanning probe microscopy (SPM). A combination of powder XRD, high resolution scanning tunneling microscopy (STM), and atomic force microscopy (AFM) experiments revealed the formation of nano-segregated well-ordered columnar tubular superstructures consisting of about five molecules in the column stratum. These self-assembled columns are further self-organized into a two-dimensional oblique unit cell lattice. Semiconducting behavior of this compound has been studied by pulse-radiolysis time-resolved microwave conductivity (PR-TRMC) method and charge carrier mobility values of ∼10(-2) cm(2) V(-1) s(-1) are observed. Such organized columnar superstructures constructed from semisynthetic zinc chlorins are reminiscent of the tubular organization of the bacteriochlorophyll dyes in the light-harvesting chlorosomal antennae of green sulphur bacteria.
从天然叶绿素 a (Chl a) 出发，合成了一种具有中心锌离子、3(1)-位甲氧基官能团和第二代树枝状分子（3,4-3,4,5）12G2-CH(2)OH 在 17(2)-位功能化的叶绿素衍生物。该化合物表现出液晶（LC）行为，其介晶性质已通过差示扫描量热法（DSC）、偏光显微镜（POM）、粉末 X 射线衍射（XRD）和扫描探针显微镜（SPM）进行了表征。粉末 XRD、高分辨率扫描隧道显微镜（STM）和原子力显微镜（AFM）实验的组合表明，形成了由约五个分子组成的纳米分离有序柱状管状超结构，在柱层中。这些自组装的柱子进一步自组织成二维斜单位晶格。通过脉冲辐射时间分辨微波电导率（PR-TRMC）方法研究了该化合物的半导体行为，观察到载流子迁移率值约为 10(-2) cm(2) V(-1) s(-1)。这种由半合成锌叶绿素构建的有序柱状超结构让人联想到绿色硫细菌光收集叶绿素天线中细菌叶绿素染料的管状组织。
