Compounds of formula wherein X is O, X 0 is O, Y is O, n is 0 or 1, m is 0 or 1, n+m is 1 or 2, - - is selected from the group consisting of formula to formula, X 1, X 2, X 3, X 4 are each independently of each other CR' or N, X 5 is each independently O, S, C=O or NR 0, X 6, X 7 are each independently CR' or N, R is at each occurrence independently selected from the group consisting of H, F, a linear or branched alkyl group having 1 to 4 C atoms or a linear or branched partially or fully fluorinated alkyl group having 1 to 4 C atoms, R' is at each occurrence independently selected from the group consisting of H, F, a linear or branched, non-halogenated, partially or completely halogenated alkyl group having 1 to 20 C atoms, a linear or branched hydroxyalkyl group having 1 to 20 C atoms, a non-halogenated, partially or completely halogenated cycloalkyl group having 3 to 6 C atoms, a linear or branched, non-halogenated, partially or completely halogenated alkoxy group having 1 to 20 C atoms, a linear or branched, non-halogenated, partially or completely halogenated thioalkyl group having 1 to 20 C atoms, R 0 is at each occurrence independently selected from the group consisting of a linear or branched alkyl group having 1 to 10 C atoms or a cycloalkyl group having 3 to 6 C atoms, R 1 is at each occurrence independently a triethoxysilyl or a diethoxymethylsilyl radical, -R 2 - is -(C 2) o -, -(C 2) p -X 8 -(C 2) q -(X 9) s -(C 2) r -(X 10) t -(C 2) u - or a cycloalkylene group having 5 or 6 C atoms which can be substituted with at least one R which is different from H, o is selected from the group consisting of 1 to 20, X 8, X 9, X 10 are at each occurrence independently O, S or NR 0, s, t is 0 or 1, p, q are at each occurrence independently selected from the group consisting of 1 to 10, r, u are at each occurrence independently selected from the group consisting of 0 to 10, wherein the overall number of atoms for -(C 2) p -X 8 -(C 2) q -(X 9),-(C 2) r -(X 10) t -(C 2) u - is up to 20 atoms, R 3, R 4, R 5, R 6 are at each occurrence independently R', R 7 is R' in case m is 0 and R 7 is R 1 in case m is 1. X is O, X 0 is O, Y is O, n is 0 or 1, m is 0 or 1, n+m is 1 or 2, - - is selected from the group consisting of formula to formula, X 1, X 2, X 3, X 4 are each independently of each other CR' or N, X 5 is each independently O, S, C=O or NR 0, X 6, X 7 are each independently CR' or N, R is at each occurrence independently selected from the group consisting of H, F, a linear or branched alkyl group having 1 to 4 C atoms or a linear or branched partially or fully fluorinated alkyl group having 1 to 4 C atoms, R' is at each occurrence independently selected from the group consisting of H, F, a linear or branched, non-halogenated, partially or completely halogenated alkyl group having 1 to 20 C atoms, a linear or branched hydroxyalkyl group having 1 to 20 C atoms, a non-halogenated, partially or completely halogenated cycloalkyl group having 3 to 6 C atoms, a linear or branched, non-halogenated, partially or completely halogenated alkoxy group having 1 to 20 C atoms, a linear or branched, non-halogenated, partially or completely halogenated thioalkyl group having 1 to 20 C atoms, R 0 is at each occurrence independently selected from the group consisting of a linear or branched alkyl group having 1 to 10 C atoms or a cycloalkyl group having 3 to 6 C atoms, R 1 is at each occurrence independently a triethoxysilyl or a diethoxymethylsilyl radical, -R 2 - is -(C 2) o -, -(C 2) p -X 8 -(C 2) q -(X 9) s -(C 2) r -(X 10) t -(C 2) u - or a cycloalkylene group having 5 or 6 C atoms which can be substituted with at least one R which is different from H, o is selected from the group consisting of 1 to 20, X 8, X 9, X 10 are at each occurrence independently O, S or NR 0, s, t is 0 or 1, p, q are at each occurrence independently selected from the group consisting of 1 to 10, r, u are at each occurrence independently selected from the group consisting of 0 to 10, wherein the overall number of atoms for -(C 2) p -X 8 -(C 2) q -(X 9),-(C 2) r -(X 10) t -(C 2) u - is up to 20 atoms, R 3, R 4, R 5, R 6 are at each occurrence independently R', R 7 is R' in case m is 0 and R 7 is R 1 in case m is 1.