plurality of BB1 are present, the respective BB1 may be the same or different, and each of RB1 and RB2 which are independent of each other, is a hydrogen atom or an optional substituent.) (Wherein each of BB1???, CB1??? and DB1??? which are independent of one another, represents an aromatic ring, and the aromatic ring may have an optional substituent, mB1??? represents an integer of from 0 to 1, n