Creation of New Extended Pi-Electronic Systems Composed by Conjugated Polyynes

本计画的目的之一是合成纳米尺度的平面π电子化合物，并研究其性质，以阐明由sp和sp^2杂化碳组成的未知碳同素异形体的新性质。此外，还研究了在溶液和气相中通过生成和环化高活性的三维共轭多炔化合物来合成富勒烯，以及在高级富勒烯和杂富勒烯的合成中的应用。在扩展类石墨π体系的合成方面，制备了外部大环化合物，并研究了它们在溶液中的聚集行为。结果表明，这些分子在非极性溶剂中由于π-π堆积相互作用而缔合形成二聚体。相反，它们在极性溶剂中主要由于疏溶剂相互作用而形成具有纳米管状结构的较高聚集体。另一方面，发展了以六乙炔基苯为核心的衍生物的高效合成方法，并将其应用于石墨烯基序分子前体的合成。此外，我们还研究了碳碳三键的引入、高活性中间体的生成及其作为过渡金属配合物的拦截等新方法，在多环多炔化合物合成富勒烯方面，我们成功地<60>利用多炔前体的激光解吸质谱检测到了C_2离子。该方法已成功地应用于二氮富勒烯C_<58>N_2和低级富勒烯C_的检测<36>。然而，通过热解和烘箱-激光分解前驱体来制备宏观量的C_2的尝试<60>是不成功的。在多炔环化反应中，研究了二芳基二烯炔的热环化反应。

On of the purposes of this project is to synthesize planar pi-electronic compounds of nanoscale regime and to investigate their properties to elucidate novel properties of unknown carbon allotropes composed by sp and sp^2-hybridyzed carbons. In addition, synthesis of fullerenes in solution or in vapor phase by the generation and cyclizatipn of highly reactive, three-dimensional conjugate polyynes was investigated as well as its application to the generation of higher fullerenes and heterofullerenes.With regard to the synthesis of extended graphite-like pi-systems the external macrocyclic compounds were prepared and their aggregation behavior in; solution was investigated. As a result, it was revealed that these molecules associate in non-polar solvents to form dimers due to pi-pi stacking-interactions. In contrast, they formed higher aggregates having nanotube-like structure in polar solvent mainly due to solvophobic interactions. On the other hand, the efficient synthetic method for the core hexaethynylbenzene derivatives was developed which was adopted to the synthesis of precursors of graphyne motif molecules. In addition, new methods for the introduction of carbon-carbon triple bonds and generation of highly reactive intermediates and their interception as transition metal complexes were investigated.Regarding the synthesis of fullerenes from polycyclic polyynes, we succeeded in the detection of C_<60> ions in the laser-desorption mass spectrometry of polyyne precursors. This method was applied to the successful detection of diazafullerene C_<58>N_2 and lower fullerene C_<36>. However, attempts to prepare macroscopic amount of C_<60> by pyrolysis and oven-laser decomposition of the precursors were unsuccessful. In connection to the polyyne cyclization, thermal, cyclization of diaryIdienynes to form polycyclic aromatic compounds was investigated.