Patent ID: 7771704

Claim:
A radioactive transition metal-imido hetero-diphosphine complex compound of formula (I): [( Me= N—R)L 1 L 2 ] + Z − (I), wherein: Me is a radioactive transition metal selected from the group consisting of 99m Tc, 186 Re, 188 Re; R is a C 1 -C 15 linear or branched alkyl or alkenyl residue, optionally interrupted by —O—, —S—, —N(R′)—, where R′═H or C 1 -C 6 alkyl, and/or optionally substituted with halogen, hydroxy, C 1 -C 5 alkoxy, carboxy, ester, thiol, primary or secondary amino or amido, groups, or R is phenyl or an aryl residue; L 1 is a tridentate hetero-diphosphine ligand of formula (II): wherein: R 1 , R 2 , R 3 and R 4 , which may be the same or different, are: a C 1 -C 15 linear or branched alkyl or alkenyl residue, optionally interrupted by —O—, —S—, —N(R′)—, where R′=H or C 1 -C 6 alkyl, and/or optionally substituted with halogen, hydroxy, C 1 -C 5 alkoxy, carboxy, ester, thiol, primary or secondary amino or amido groups, or R 1 , R 2 , R 3 and R 4 are a phenyl or an aryl residue, R 1 , R 2 , R 3 and R 4 being optionally substituted with a biologically active substance, wherein said biologically active substance is selected from the group consisting of sugars, amino acids, fatty acids, vitamins, hormones, peptides and catecholamines, said catecholamines being optionally conjugated, via peptidic bond, to another biologically active substance selected from the group consisting of sugars, amino acids, fatty acids, vitamins, hormones and peptides; X is oxygen, sulphur, NR 5 , wherein R 5 is hydrogen or R; n is an integer ranging from 1 to 5; L 2 is a bidentate ligand, which comprises a combination of two electron-donor atoms selected from the group consisting of [O − ,O − ], [N − ,O − ], [S − ,O − ], [N − ,N − ], [N − ,S − ] and [S − ,S − ], said atoms being separated by a 2 to 4 membered spacer, wherein said spacer is an aliphatic chain or part of an aromatic ring, L 2 being optionally conjugated to a biologically active substance as above defined; Z − is a mononegative counter-ion selected from the group consisting of Cl − , Br − , OH − , ClO 4 − , EtO − , tetrafluoroborate.