Use of ascorbic acid derivatives for the functionalization of matrices

A compound of the formula I

• where
• R1 or R2 is each, independently of one another, hydroxyl, —O-alkyl, —OC(O)-alkyl, —OPO3M or O-glycosyl,
• alkyl is C1-C6-alkyl,
• M is an alkali or alkaline-earth metal cation or H,
• R3 or R4 are each, independently of one another, hydroxyl or a radical B and
• B is a substituent of the formula II, III, IV, V, VI, VII, VIII, IX, X, XI and/or XII
• where
• R5 to R16 each, independently of one another, denote H, —OH, —OA, -A, —NH2, —NHA, —NA2, —NH—(CH2—CH2—O)n—H, —N[(CH2—CH2—O)n—H]2, —[NHA2]X, —[NA3]X, —SO3H, —[SO3]X or 2H-benzotriazol-2-yl and
• A is alkyl having 1 to 4 C atoms,
• n is an integer from 1 to 25,
• X is the counterion to the cations [NHA2]+ and [NA3]+ or to the anion [SO3]− and
• Y and Z are each, independently of one another, -ascorbyl, hydroxyl, —O-2-ethylhexyl, —O-hexyl, —OA or —NH—C(CH3)3,
• where for R5 to R9 in formula IV, the radicals H, OH and OA are excluded, apart from the case where at least one substituent from R5 to R9 denotes A, —NH2, —NHA, —NA2, —NH—(CH2—CH2—O)n—H, —N[(CH2—CH2—O)n—H]2, —[NHA2]X, —[NA3]X, —SO3H, —[SO3]X or 2H-benzotriazol-2-yl, and
• with the proviso that at least one of the radicals R3 or R4 stands for a radical B.

An agent comprising at least one compound of the formula I

• where
• R1 or R2 each, independently of one another, denote hydroxyl, —O-alkyl, —OC(O)-alkyl, —OPO3M or O-glycosyl,
• alkyl denotes C1-C6-alkyl,
• M denotes an alkali or alkaline-earth metal cation or H,
• R3 or R4 each, independently of one another, denote hydroxyl or a radical B, and
• B denotes the radical of a pharmacological, fungicidal, herbicidal, insecticidal or cosmetic active compound, of an X-ray contrast agent or of a dye,
• with the proviso that at least one of the radicals R3 or R4 stands for a radical B.