The Ï-donor strength of extended tetrathiafulvalenes (TTFs) has been investigated as a function of the electronic character and length of the spacer between the two dithiole rings. First and second ionisation energies were calculated with B3LYP/6-311++G(2d,p)//B3LYP/6-31+G(d) and B3LYP/6-311++G(2d,p)//PM3 computational methods and correlated with the number of carbon atoms in the spacer. Theoretical IEs are compared to electrochemical oxidation potentials Eoxs to elucidate the importance of solvation. There are remarkable differences between spacers comprised of sp2 and sp carbon atoms. Thus, Eox increases with IE for alkene spacers whereas there is no clear correlation for alkyne spacers, which is ascribed to a solvent effect. Calculations using a continuum solvent model support this interpretation. Moreover, we report the synthesis of a new alkyne-extended TTF that contains six triple bonds in the spacer. Its redox properties were investigated and discussed in context of the calculations. Finally, the donor strength of an alkyne-extended TTF, bis(1,3-dithiol-2-ylidene)hexa-2,4-diyne, was evaluated by its ability to form an inclusion complex with the cyclic acceptor cyclobis(paraquat-p-phenylene).
作为电子特性和两个二
硫环之间间隔长度的一个函数,对
四硫富瓦烯(
TTF)的供体强度进行了研究。用B3LYP/6-311++G(2d,p)//B3LYP/6-31+G(d)和B3LYP/6-311++G(2d,p)//PM3计算方法计算了第一和第二电离能,并与间隔中的碳原子数相关联。将理论IE与电
化学氧化电位Eoxs进行比较,以阐明溶剂化的重要性。由sp2和sp碳原子组成的间隔之间存在显着差异。因此,对于烯烃间隔,Eox随IE增加而增加,而对于
炔烃间隔,则没有明显的关联,这归因于溶剂效应。使用连续溶剂模型进行的计算支持了这一解释。此外,我们报告了一种新的
炔烃-
TTF的合成,该
炔烃-
TTF在间隔中包含六个三键。在计算的背景下对其氧化还原性质进行了研究和讨论。最后,通过
炔烃-
TTF(双(1,3-二
硫醇-2-亚基)六-2,4-二炔)与环状受体环状双(对
四氮唑-对苯基)形成包合复合物的能力,