Benzodioxepin-3-one compounds as dyes or as fluorescent emitters

Compounds of the formula I

• where
• R1, R2, R3 and R4 each, independently of one another, denotes H, NO2, Hal, a straight-chain or branched alkyl group having 1 to 20 C atoms or a straight-chain or branched alkoxy group having 1 to 20 C atoms,
• X and Y each, independently of one another, denote
• an aryl or heteroaryl group having 5 to 24 ring atoms which is unsubstituted or mono- or polysubstituted by R, or
• a group of aryl and/or heteroaryl groups having 5 to 24 ring atoms which are unsubstituted or mono- or polysubstituted by R, where the aryl and/or heteroaryl groups in this group are each linked, independently of one another, singly or multiply, by a single bond, a double bond, conjugated double bonds, a C atom or by a unit of the formula (CHR5)n-(Het)o-(CHR5)p,
• R in each case, independently of one another on each occurrence, denotes D, Hal, alkyl, OH, O-alkyl, O-aryl, S-alkyl, NH2, NHalkyl, N(alkyl)2, N(aryl)2, cycloalkyl, O-cycloalkyl, S-cycloalkyl, NH-cycloalkyl, N(cycloalkyl)2, CN, NO2, Si(alkyl)3, B(OR6)2, C(O)R6, P(O)(R6)2, S(O)R6, S(O)2R6, a straight-chain or branched alkenyl group having 2 to 20 C atoms and one or more double bonds or a straight-chain or branched alkynyl group having 2 to 20 C atoms and at least one triple bond and optionally one or more double bonds,
• R5 in each case, independently of one another on each occurrence, denotes H, D, Hal, alkyl, OH, O-alkyl, O-aryl, S-alkyl, NH2, NHalkyl, N(alkyl)2, N(aryl)2, cycloalkyl, O-cycloalkyl, S-cycloalkyl, NH-cycloalkyl, N(cycloalkyl)2, CN, NO2, Si(alkyl)3, B(OR6)2, C(O)R6, C(O)2R6, P(O)(R6)2, S(O)R6, S(O)2R6, a straight-chain or branched alkenyl group having 2 to 20 C atoms and one or more double bonds or a straight-chain or branched alkynyl group having 2 to 20 C atoms and at least one triple bond and optionally one or more double bonds,
• R6 in each case, independently of one another, denotes H, D, OH, alkyl, aryl, cycloalkyl, Oalkyl, Oaryl or O-cycloalkyl,
• alkyl denotes a straight-chain or branched alkyl group having 1 to 20 C atoms, which may be partially or fully substituted by halogen,
• cycloalkyl denotes a cyclic saturated or partially unsaturated cycloalkyl group having 3 to 7 C atoms,
• aryl denotes an aryl group having 6 to 10 C atoms, which may be mono- or polysubstituted by alkyl, Oalkyl, N(alkyl)2 or Hal,
• Hal denotes F, Cl, Br or I,
• Het denotes O, S, —N═N—, NH or NR,
• n denotes an integer from 0 to 5,
• o denotes 0 or 1,
• p denotes an integer from 0 to 5,
• n+o+p denotes at least the number 1
• and salts, tautomers, steroisomers thereof, including mixtures thereof in all ratios, and/or solvates.