Consequently, COT with one benzene extended does not exhibit fluorescence in the solution or solid-state, whereas COT with two benzene extended was non-fluorescence in various solutions at room temperature but displayed intense fluorescence in the solid state (green emission in the crystalline state) with clear aggregation-induced emission (AIE) characteristics, meanwhile, enhanced blue fluorescence behavior were found upon gradual cooling from 296K to 103K in dilute 2-MTHF solution ( Figure ). COT with three benzene extended displayed fluorescence in both solution and the solid state and also exhibited enhanced emission at low temperatures . These investigations provided a solid foundation for the development of novel RIV-type AIEgens.