Preparation of TTF-bsed Oligomeric Donor Hosts with Flexible Structure

三维组装的TTF衍生物通过它们的分子结构可以表现出明显不同的性质和/或功能，这是由于它们的形状与单体TTF衍生物的基本上平坦的性质完全不同。以前我们制备了TTF二聚体，其中两个TTF部分通过四个亚烷基二硫代链平行或正交地保持，并且它们的电结晶产生了独特的电子和/或磁性的配合物。它们由3 ~ 4个TTF基团组成，通过“诱导配合”与富勒烯等大的三维受体形成超分子组装体，中心TTF基团通过两个丙二硫基与两个外接TTF基团连接的线型结构已被成功制备。两个被保护的硫醇基团位于两端，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。与此相反，亚乙基二硫代同系物很难制备，这主要是由于中间体的溶解度低.已尝试制备由四个TTF组成的大环，其4-和5-C均通过亚丙基二硫代基团与相应的封端TTF部分连接。使用标准亚磷酸三烷基酯方案的相应的1，3-二硫杂环戊烯-2-酮/双环四聚体的四重TTF形成偶联仅得到不充分偶联的产物，即使在大量过量的对应物分子存在下。试图制备与亚丙基二硫基或亚乙基二硫基连接的类似环状三聚体的努力也没有成功。制备了线性TTF三聚体前体，并对其成环反应进行了研究。

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..