The fused molecules NBNN-1f and NBNN-2f exhibit aggregation-induced emission (AIE) behavior, while compounds NBNN-1 -NBNN-5 only have normal properties. AIE behavior of NBNN-1f and NBNN-2f is probably due to their structure constraint. We used NBNN-1f as an example to investigate the AIE phenomenon in detail (Figure ). The red emission became stronger after the water content in volume reached 50% in THF, the emission intensity grew faster when water was further added, as shown in Figure and 5c. The THF solution with 90% water displayed bright red emission. The quantum yields gradually increased when water fraction increased. In addition, we found that the AIE behavior of NBNN-1f was accompanied by the blue-shift of emission (Figure ). AIE behavior of NBNN-1f was further demonstrated through change of emission intensity after adding one drop of NBNN-1f THF solution on a thin-layer chromatography plate (Figure ). We observed a notable increase of the red emission under 365 nm UV lamp irradiation.