Compounds for imaging and therapy

A metal complex of formula (III):

• wherein:
• M is a Cu;
• A1 is:
• n is 0 or an integer of 1 to 5;
• A2, X and Y are as defined in (i), (ii) and (iii) which follow:
• (i) A2 is
• X is N or P and A1 is attached to X via a double bond, or X is O, S, N(R5) or P(R5) and A1 is attached to X via a single bond;
• and Y is N, O, P, S, N(R5), O(R5), P(R5) or S(R5);
• or
• (ii) X is N or P and A1 is attached to X via a double bond, or X is O, S, N(R5) or P(R5) and A1 is attached to X via a single bond;
• and Y and A2 together represent a moiety of formula (B):
• wherein the ring that is substituted by L1-R1 is a 5- to 11-membered heterocyclic group;
• or
• (iii) X, A2 and Y together represent
• wherein T is OH, O—, COOH or C(O)O— and rings b and c are aromatic C6-10 carbocyclic or 5 to 11 membered aromatic heterocyclic groups;
• X′ is N and A1 is attached to X′ via a double bond, or X′ is N(R5), O, S or P(R5) and A1 is attached to X′ via a single bond;
• L1 and L1′, which are the same or different, are each independently selected from a covalent bond and a linker group selected from —C(O)—, -alk—C(O)—, —C(O)O—, -alk—C(O)O—, —OC(O)—, -alk—OC(O)—, —O—, -alk—O—, —N(R7)—, -alk—N(R7)—, —N(R7)C(O), -alk—N(R7)C(O)—, —C(O)N(R7), -alk—C(O)N(R7), —C(S)—, -alk—C(S)—, —S—, -alk—S—, —C(S)N(R7)—, -alk—C(S)N(R7)—, —N(R7)C(S)—, -alk—N(R7)C(S)—, —S(O)2N(R7)—, -alk—S(O)2N(R7)—, —N(R7)S(O)2—, -alk—N(R7)S(O)2—, —S(O)—, -alk—S(O)—, —N(R7)C(O)O—, -alk—N(R7)C(O)O—, —OC(O)N(R7)—, -alk—OC(O)N(R7)—, —N(R7)C(O)N(R7)—, -alk—N(R7)C(O)N(R7)—, —N(R7)C(S)N(R7)—, -alk—N(R7)C(S)N(R7)—, —N═C(R7)—, -alk—N═C(R7)—, —C(R7)=N— and -alk—C(R7)=N—;
• R1 and R1′, which are the same or different, are each independently selected from hydrogen, Z, L3—Z, L3-alk—Z, —V—L3—Z, —V—L3-alk—Z, alk—V—L3—Z, -alk—V—L3-alk—Z and a substituted or unsubstituted group selected from an alkyl, amino, carbocyclic, cycloalkyl, heterocyclic, -alk-carbocyclic, -alk-cycloalkyl and -alk-heterocyclic group, which group may be further substituted by L3—Z or L3-alk—Z, wherein L3 is as defined above for L1 and L1′, —V— is a linking group of the following formula:
• wherein P2 and Q2 are independently selected from N, O, P and S and M2 is a metal atom, and Z is a moiety selected from a biologically active molecule, a fluorophore, a cytotoxin, an amino acid, a peptide, an oligopeptide, a polypeptide, a sugar, a group containing a label, a leaving group which is replaceable by a group containing a label, and a complex of Cu, Zn or Ni with a bis(thiosemicarbazone) or a thiosemicarbazone;
• -alk- is an alkylene, alkenylene or alkynylene group based on an alkyl, alkenyl or alkynyl group;
• R2 and R2′, which are the same or different, are each independently selected from H, C1-C6 alkyl and C1-C6 alkoxy;
• each R3 is independently selected from H, C1-C6 alkyl, heterocyclic group and phenyl;
• each R4 is independently selected from H, C1-C6 alkyl, heterocyclic group and phenyl;
• each R5 is independently selected from H, C1-C6 alkyl and a group comprising an electron donor group, which donor group is separated by two carbon atoms from the O, N, S or P atom to which R5 is attached;
• R7 is H, alkyl or cycloalkyl;
• each R10 is independently selected from H, C1-C6 alkyl, heterocyclic group and phenyl;
• and L2 is —C(O)— or a covalent bond;
• with the proviso that when X and X′ are both N, Y is S, A1 is (a′) and A2 is (d) then either the moiety represented by L1-R1 or the moiety represented by L1′-R1′ is other than H, unsubstituted alkyl or unsubstituted alkoxy.