Lowering Band Gap of an Electroactive Metal–Organic Framework via Complementary Guest Intercalation

A new honeycomb-shaped electroactive metal–organic framework (MOF) has been constructed from an electron deficient naphthalenediimide (NDI) ligand equipped with two terminal salicylic acid groups. π-Intercalation of electron-rich planar tetrathiafulvalene (TTF) guests between the NDI ligands stacked along the walls lowers the electronic band gap of the material by ca. 1 eV. An improved electron delocalization through the guest-mediated π-donor/acceptor stacks is attributed to the diminished band gap of the doped material, which forecasts an improved electrical conductivity.

本研究构筑了一种新型蜂窝状电活性金属有机框架（metal–organic framework, MOF），该框架由带有两个末端水杨酸基团的缺电子萘二酰亚胺（naphthalenediimide, NDI）配体构建而成。沿该框架孔壁堆叠的NDI配体之间，富电子平面型四硫富瓦烯（tetrathiafulvalene, TTF）客体发生π插层作用，使该材料的电子带隙降低约1 eV。掺杂后材料的带隙缩减可归因于客体介导的π给体/受体堆叠体系所实现的电子离域程度提升，这预示着该材料的导电性能将得到改善。