Abstract: It is provided a pentafluorophosphate derivative according to general formula (I): or a pharmaceutically acceptable salt or solvate thereof. Thereby, R1 and R2 denote independently from each other H or F; R3 denotes H, a C1-C10 alkyl optionally substituted by a hydrocarbon chain comprising an amide function and/or a carboxyl function, or by a substituent chosen from the group consisting of alkyl, alkylamino, alkylaminocarboxy, carboxy, alkoxycarbonyl, hydroxy, N-morpholino, N-morpholinoalkyl, N-morpholinocarbonyl, N-methyl-N-piperazinyl, N-methyl-N-piperazinylalkyl, N-methyl-N-piperazinylcarbonyl, and sulfo, an optionally substituted C3-C10 cycloalkyl, or an optionally substituted C6-C20 aryl, wherein a hydrocarbon chain of the alkyl, the cycloalkyl or the aryl can be interrupted by one or more oxygen, sulfur and/or nitrogen atoms; and M denotes any cation; with the proviso that at least one of R1 and R2 denotes F, if R3 denotes H.