| 主权项 |
1. A compound represented by the following formula (1), wherein R1 to R9 are independently selected from the group consisting of alkyl group having 1 to 20 carbon atoms, halogen atom, hydroxyl group, hydrogen atom, cyano group, sulfonyl group, sulfo group, sulfato group, silyl ether, organosilicon, deuterium atom, sulfonyl ester, nitro group, aryl group, nitro group, carboxyl group and alkoxy group having 1 to 20 carbon atoms; X is a linking group selected from aromatic, alicyclic or aliphatic groups or combination thereof; n is an integer from 2 to 6; m is an integer from 0 to 5; n is larger than m. |
