properties. From this study we could draw the following conclusions: 1). The emission color of the compounds not only depends on the donor strength but also shows a large red-shift when same donors are substituted from position 3/6 to position 11/12 of the BP acceptor; 2). The kRISC for the compounds substituted in positions 11 and 12 of BP is more than ten times faster than that of compounds substituted in positions 3 and 6; 3). 2GCzBP exhibits the highest ΦPL of 77%, the ΦPL slightly decease to 68% for 2FBP2GCz, wherein both compounds have donors