a C3-C10 cycloalkyl group, a C1-C10 heterocycloalkyl group, a C3-C10 cycloalkenyl group, a C1-C10 heterocycloalkenyl group, a C6-C60 aryl group, a C6-C60 aryloxy group, a C6-C60 arylthio group, a C1-C60 heteroaryl group, a monovalent non-aromatic condensed polycyclic group, or a monovalent non-aromatic condensed heteropolycyclic group; or —O(Q31), —S(Q31), —Si(Q31)(Q32)(Q33), —N(Q31)(Q32), —B(Q31)(Q32), —P(Q31)(Q32), —C(═O)(Q31), —S(═O)2(Q31), or —P(═O)(Q31)(Q32), which may each be substituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a C1-C60 alkyl group, a C2-C60 alkenyl group, a C2-C60 alkynyl group, a C1-C60 alkoxy group, a C3-C10 cycloalkyl group, a C1-C10 heterocycloalkyl group, a C3-C10 cycloalkenyl group, a C1-C10 heterocycloalkenyl group, a C6-C60 aryl group, a C6-C60 aryloxy group, a C6-C60 arylthio group, a C1-C60 heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —O(Q21), —S(Q21), —Si(Q21)(Q22)(Q23), —N(Q21)(Q22), —B(Q21)(Q22), —P(Q21)(Q22), —C(═O)(Q21), —S(═O)2(Q21), or —P(═O)(Q21)(Q22),