Metallocene compounds and labeled molecules comprising the same for in vivo imaging

Metallocene compound of general formula (I):

• wherein:
• M is a metal selected from the group consisting of titanium, zirconium and hafnium;
• X1 and X2, which can be the same or different, are a halogen atom, a R′, OR′, OCOR′, SR′, NR′2 or PR′2 group, wherein the R′ substituents are linear or branched, saturated or unsaturated C1-C20 alkyl, C3-C20 cycloalkyl, C6-C20 aryl, C7-C20 alkylaryl, C7-C20 arylalkyl radicals, optionally containing one or more heteroatoms belonging to the groups 13-17 of the Periodic Table of the Elements;
• X1 and X2 can also be interconnected via a cyclic structure of <40 atoms comprising one or more of C, N, O, F, Si, B, P;
• R1, R2, R3, R4, R5, R6, R7, R8 and R9, the same or different, are H or linear or branched, saturated or unsaturated C1-C20 alkyl, C3-C20 cycloalkyl, C6-C20 aryl, C7-C20 alkylaryl, C7-C20 arylalkyl radicals, optionally containing one or more heteroatoms belonging to the groups 13-17 of the Periodic Table of the Elements;
• two or more adjacent R1, R2, R3, R4, R5, R6, R7, R8 and R9 groups on a cyclopentadienyl residue may be connected by a saturated or unsaturated bridge containing up to 40 atoms comprising one or more of C, N, S, O, F, Si, B, P, said bridge optionally containing or being part of up to 5 carbo- or hetero-cycles;
• L is a linker having a functional end, selected from the group consisting of:
• wherein:
• Ph=phenyl;
• X=R′NH, in which R′ is as defined above;
• R is selected from the group consisting of F, CH2F, CHF2, CF3, OCF3;
• Ar is C6-C20 aryl, C7-C20 alkylaryl, or C7-C20 arylalkyl radical, optionally containing one or more heteroatoms belonging to the groups 13-17 of the Periodic Table of the Elements;
• m=2-20;
• wherein the functional end of said linker group L is optionally protected.