Department of Chemistry, Shandong University, Jinan 250100, China.
Langmuir. 2010 Mar 2;26(5):3678-84. doi: 10.1021/la903141t.
Solution-vapor annealing of drop-cast thin films of meso-5,10,15,20-tetra-n-decylporphyrin H(2)T(C(10)H(21))(4)P deposited on SiO(2) substrate and quartz leads to the formation of well-defined self-assemblies. Their self-assembling properties in n-hexane vapor and chloroform vapor were comparatively investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD) technique, and IR and UV-vis spectroscopy. Intermolecular pi-pi interaction in cooperation with the van der Waals interaction of metal free porphyrin and solvent-solute interaction leads to the formation of microleaves and microtube dendrites in n-hexane vapor and chloroform vapor, respectively. Electronic absorption spectroscopic data on the self-assembled microstructures reveal the J-aggregate nature in both the microleaves and microtube dendrites. However, the difference in the shift of the Soret and Q bands for the two kinds of aggregates relative to corresponding solution absorption bands indicates the dependence of the solvent-porphyrin molecular interaction during the annealing self-assembly process, which counterbalances the intermolecular interactions, particularly the hydrophobic interaction between side chains. IR and XRD results clearly reveal the higher molecular ordering nature of microtube dendrites than that of microleaves, further confirming the effect of the solvent on tuning the intermolecular interaction and in turn the molecular packing mode in aggregates of porphryin compounds. The present results appear to represent the first example of orderly micrometer-sized tube junctions and dendrites of porphyrin prepared through a self-assembly process, providing an effective and new method toward the synthesis of complicated nanotubular structures. In addition, micrometer-sized leaves and tube dendrites were revealed to show good semiconductor features. Highly reproducible and sensitive gas response characteristics have also been observed in these microstructures.
溶液-蒸汽退火处理将介孔 5,10,15,20-四正癸基卟啉 H(2)T(C(10)H(21))(4)P 的旋涂薄膜沉积在 SiO(2) 基底和石英上，得到了具有良好形貌的自组装结构。通过扫描电子显微镜（SEM）、X 射线衍射（XRD）技术、红外（IR）和紫外-可见（UV-vis）光谱对其在正己烷蒸气和氯仿蒸气中的自组装性能进行了比较研究。无金属卟啉的分子间 π-π 相互作用与范德华相互作用以及溶剂-溶质相互作用导致在正己烷蒸气和氯仿蒸气中分别形成了微叶片和微管树枝状结构。自组装微结构的电子吸收光谱数据表明，在微叶片和微管树枝状结构中均存在 J-聚集体。然而，两种聚集体的 Soret 和 Q 带相对于相应溶液吸收带的位移差异表明，在退火自组装过程中溶剂-卟啉分子相互作用的依赖性，这种依赖性平衡了分子间相互作用，特别是侧链之间的疏水相互作用。IR 和 XRD 结果清楚地表明，微管树枝状结构的分子有序性高于微叶片，进一步证实了溶剂对调节分子间相互作用以及卟啉化合物聚集体中分子堆积模式的影响。这些结果似乎代表了通过自组装过程制备的有序微米级管状结和卟啉树枝状结构的首例实例，为复杂的管状结构合成提供了一种有效且新颖的方法。此外，微米级叶片和管状树枝状结构显示出良好的半导体特性。在这些微结构中还观察到了具有高度重现性和灵敏的气体响应特性。
