A compound represented by formula: wherein: Ar is a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenylyl group, a substituted or unsubstituted naphthyl group, or a substituted or unsubstituted phenanthryl group; R 1 to R 7 are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or a cycloalkyl group having 3 to 6 ring carbon atoms; R 11 to R 14 are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or a cycloalkyl group having 3 to 6 ring carbon atoms; R 21 to R 24 are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or a cycloalkyl group having 3 to 6 ring carbon atoms; R 31 to R 34 are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or a cycloalkyl group having 3 to 6 ring carbon atoms; R 41 to R 48 are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or a cycloalkyl group having 3 to 6 ring carbon atoms, provided that one selected from R 47 and R 48 is a single bond bonded to *1; the optional substituent for the phenyl group, the biphenylyl group, the naphthyl group, and the phenanthryl group is independently a halogen atom, an alkyl group having 1 to 10 carbon atoms, or a cycloalkyl group having 3 to 6 ring carbon atoms; adjacent two selected from R 1 to R 7, R 11 to R 14, R 21 to R 24, R 31 to R 34, and R 41 to R 48 not the single bond bonded to *1 are not bonded to each other thereby failing to form a ring structure; and if the phenyl group, the biphenylyl group, the naphthyl group, or the phenanthryl group has adjacent two optional substituents, the adjacent two optional substituents are not bonded to each other thereby failing to form a ring. Ar is a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenylyl group, a substituted or unsubstituted naphthyl group, or a substituted or unsubstituted phenanthryl group; R 1 to R 7 are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or a cycloalkyl group having 3 to 6 ring carbon atoms; R 11 to R 14 are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or a cycloalkyl group having 3 to 6 ring carbon atoms; R 21 to R 24 are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or a cycloalkyl group having 3 to 6 ring carbon atoms; R 31 to R 34 are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or a cycloalkyl group having 3 to 6 ring carbon atoms; R 41 to R 48 are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or a cycloalkyl group having 3 to 6 ring carbon atoms, provided that one selected from R 47 and R 48 is a single bond bonded to *1; the optional substituent for the phenyl group, the biphenylyl group, the naphthyl group, and the phenanthryl group is independently a halogen atom, an alkyl group having 1 to 10 carbon atoms, or a cycloalkyl group having 3 to 6 ring carbon atoms; adjacent two selected from R 1 to R 7, R 11 to R 14, R 21 to R 24, R 31 to R 34, and R 41 to R 48 not the single bond bonded to *1 are not bonded to each other thereby failing to form a ring structure; and if the phenyl group, the biphenylyl group, the naphthyl group, or the phenanthryl group has adjacent two optional substituents, the adjacent two optional substituents are not bonded to each other thereby failing to form a ring.