<i>C</i>_3<i>v</i>-Symmetrical Tribenzotriquinacenes as Hosts for C₆₀ and C₇₀ in Solution and in the Solid State

Various tribenzotriquinacenes (TBTQs), most of which incorporate six functional groups at the periphery of their C3v-symmetrical, rigid and convex−concave molecular framework, have been studied with respect to their ability to form supramolecular complexes with the C60 and C70 fullerenes, either in the solid state or in solution. The hexabromo derivative Br6-TBTQ was cocrystallized with C60 as [Br6-TBTQ⊂C60·toluene] but, as studied by UV/vis and 1H NMR spectroscopy, aggregation in benzene, toluene, or carbon disulfide solutions was not observed. Likewise, in contrast to the related C5v-symmetrical decakis(alkylthio)corannulenes, neither the parent hydrocarbon, nor a related hexamethoxy, or two hexakis(alkylthio) derivatives exhibited color, or complexation-induced chemical shift (CIS) changes with C60 or C70. The novel tris(2,3-thianthreno)triquinacene (o-S2C6H4)3-TBTQ, a TBTQ derivative extended by three 1,2-benzodithiino wings, and synthesized from Br6-TBTQ, was found to form 1:1 complexes with C60 and C70 in both benzene and toluene solutions. Association constants were determined for the respective complexes, viz. (o-S2C6H4)3-TBTQ⊂C60 (Kassoc = 977 ± 56) and (o-S2C6H4)3-TBTQ⊂C70 (463 ± 49, both in benzene). The X-ray single crystal and molecular structures of the pure host and of the aggregates [(o-S2C6H4)3-TBTQ⊂2 C60·2.5 chlorobenzene] were also determined.本研究针对多种三苯并三喹吖烯（tribenzotriquinacenes, TBTQs）展开探究，其中多数分子在其具有C3v对称、刚性且凸凹结构的分子骨架外围引入了六个官能团，旨在考察其与C60、C70富勒烯形成超分子复合物的能力，研究涵盖固态与溶液两种状态。六溴代衍生物Br6-TBTQ可与C60形成共晶体[Br6-TBTQ⊂C60·甲苯]，但通过紫外-可见（UV/vis）光谱与核磁共振氢（1H NMR）谱研究发现，其在苯、甲苯或二硫化碳溶液中并未发生聚集。同样，与相关的C5v对称十（烷硫基）碗烯不同，该类化合物中的母体烃、六甲氧基衍生物以及两种六（烷硫基）衍生物，均未表现出颜色变化，也未在与C60或C70作用时出现络合诱导化学位移（CIS）变化。本研究中新合成的三(2,3-噻蒽基)三喹吖烯（(o-S2C6H4)3-TBTQ）是一类由Br6-TBTQ制备得到的TBTQ衍生物，其带有三个1,2-苯并二噻吩侧翼。该衍生物在苯与甲苯溶液中均可与C60、C70形成1:1型超分子复合物。研究测定了相应复合物的结合常数：在苯溶剂中，(o-S2C6H4)3-TBTQ⊂C60的结合常数Kassoc = 977 ± 56，(o-S2C6H4)3-TBTQ⊂C70的结合常数为463 ± 49。此外，本研究还解析了纯主体分子以及聚集体[(o-S2C6H4)3-TBTQ⊂2 C60·2.5 氯苯]的X射线单晶与分子结构。