Preparation of TTF-bsed Oligomeric Donor Hosts with Flexible Structure

由于其形状与单体TTF衍生物的基本平面性质完全不同，通过其分子结构进行三维组装的TTF衍生物可能显示出明显不同的性质和/或功能。以前我们合成了TTF二聚体，其中两个TTF二聚体通过四个亚烷基二硫代链平行或垂直连接，它们的电结晶得到了具有独特电子和/或磁性的配合物。在本研究中，我们尝试了两种(线性和环状)柔性给体主体的制备。它们由三到四个TTF部分组成，可以通过“诱导配合”与像富勒烯这样的大的三维受体形成超分子组装。成功地制备了中心TTF部分通过两个亚丙二硫基连接到两个加盖印章的TTF的线型。两个受保护的硫醇基团位于两个末端，并且可以容易地转化为各种官能团。然而，它们的性质还有待研究。相反，亚乙二硫基同系物的制备难度较大，主要是由于中间体的溶解度较低。我们尝试了由四个TTF组成的大环的制备，这些TTF的4-C和5-C都通过丙二硫基与各自的盖章TTF部分相连。相应的1，3-二硫醇-2-酮/硫酮环状四聚体使用标准的三烷基亚磷酸酯方案进行四次TTF偶联，即使在对应分子大量过剩的情况下也只能得到不充分的偶联产物。制备类似的与亚丙基二硫基或亚乙基二硫基连接的环状三聚体的努力也没有成功。目前已经尝试了一种连接预制三个TTF的新路线。制备了线型TTF三聚体前驱体，并对其成环反应进行了考察。

Three-dimensionally assembled TTF derivatives through their molecular architecture may exhibit markedly different properties and/or functions due to their totally different shapes from the basically flat nature of monomeric TTF derivatives.. Previously we prepared TTF dimer in which two TTF moieties are held either parallel or orthogonal through four alkylenedithio chains and their electrocrystallization gave complexes of unique electronic and/or magnetic properties.In the present study, preparation of two kinds (linear and cyclic) of flexible donor hosts has been tried. They are made of three to four TTF moieties and may form supramolecular assemblies with large three-dimensional acceptors like fullerene through "induced fit".Linear types in which the central TTF moiety is connected to the two franking TTF's through two propylenedithio groups have been successfully prepared. Two protected thiol groups are' located at both of the ends and can be easily converted to various functionalities. Their properties are, however, yet to be studied.. To the contrary, the ethylenedithio homologues are difficult to prepare, mainly due to low solubilitys of intermediates.Preparation of a macrocycle composed of four TTF's whose 4-and 5-C are both connected with a respective franking TTF moiety through propylenditho group have been tried. Quadruple TTF-forming couplings of the corresponding 1,3-dithiole-2-one/thione cyclic tetramer using standard trialkyl phosphite protocols gave only insufficiently coupled products even under the presence of a large excess of the counterpart molecule. Efforts to prepare a similar cyclic trimer connected with propylenedithio or ethylenedithio group have been also unsuccessful.Presently a new route to connect preformed three TTF's has been tried. A linear TTF trimer precursor have been prepared and its ring-forming reaction have been under scrutiny..