Luminescent metal–organic gels with tetraphenylethylene moieties: porosity and aggregation-induced emission

To develop luminescent gels, a series of metal–organic gels have been successfully synthesised based on trivalent metal ions (Al3+, Cr3+, Fe3+, Ga3+, and In3+) and tetrakis(4-carboxyphenyl)ethylene (H4TCPE) that has aggregation-induced emission (AIE) features. Among these gels, the Al-TCPE gel has both high hierarchical micro- and mesoporosity and AIE effect. The Al-TCPE aerogel consists of metal–organic framework nanocomponents as revealed by TEM and PXRD, which contribute to its high microporosity. Using tetraphenylethylene as a building block endows the Al-TCPE gel with AIE photoluminescence. The Al-TCPE gel shows potential in the selective detection of explosives with picric acid chosen as a model explosive.