The novel tetraphenylethylene derivative 4-methyl-N-[3-(1,2,2-triphenylethenyl)phenyl]benzenesulfonamide (abbreviated as MTBF), C33H27NO2S, was synthesized successfully and characterized by single-crystal X-ray diffraction, high-resolution mass spectroscopy and 1H NMR spectroscopy. MTBF crystallizes in the centrosymmetric monoclinic space group P21/c. In the crystal structure, the MTBF molecules are connected into a one-dimensional band and then a two-dimensional sheet by hydrogen bonds of the N—H...O and C—H...O types. The sheets are further linked to produce a three-dimensional network via C—H...π interactions. The molecules aggregate via these intermolecular forces, which restrain the intramolecular motions (RIM) and decrease the energy loss in the aggregation state, so as to open the radiative channels, and thus MTBF exhibits excellent fluorescence by aggregation-induced emission (AIE) enhancement.
Mechanistic connotations of restriction of intramolecular motions (RIM)
