Water soluble mono-branched and di-branched complexing agents, and corresponding lanthanide complexes

A lanthanide complex consisting of a complexing agent of formula (I) and a lanthanide:

• wherein:
• Chrom1, Chrom2 and Chrom3, independently of one another, represent a group of formula:
• provided that the compound of formula (I) comprises (i) one or two groups selected from the groups (Ia) and (Ib) and (ii) at least one L1-CO—R group;
• R is a —OR2 or —NH-E group;
• R1 is a —CO2H or —P(O)(OH)R3 group;
• R2 is H or a (C1-C4)alkyl;
• R3 is a (C1-C4)alkyl;
• phenyl optionally substituted by a —SO3− group;
• or benzyl;
• L1 is a direct bond;
• a —(CH2)r− group optionally interrupted by at least one atom selected from the group consisting of an oxygen atom, a nitrogen atom and a sulphur atom;
• a —CH═CH— group;
• a —CH═CH—CH2— group;
• a —CH2—CH═CH— group;
• or a PEG group of formula —CH2—(CH2OCH2)y—CH2OCH3, where y is an integer from 1 to 5;
• L2 is selected from the group consisting of:
• a direct bond;
• a linear or branched C1-C20 alkylene group, optionally containing one or more double or triple bonds;
• a C5-C8 cycloalkylene group;
• a C6-C14 arylene group;
• said alkylene, cycloalkylene or arylene groups optionally containing one or more heteroatoms, or one or more carbamoyl or carboxamido groups, and said alkylene, cycloalkylene or arylene groups being optionally substituted by 1 to 5 C1-C8 alkyl, C6-C14 aryl, sulfonate or oxo groups;
• and
• a divalent group of formula:
• wherein n, m, p, q are integers from 1 to 16 and e is an integer from 1 to 6;
• G is a reactive group selected from the group consisting of:
• an acrylamide, an activated ester, an aldehyde, an alkyl halide, an anhydride, an aniline, an azide, an aziridine, a carboxylic acid, a diazoalkane, a haloacetamide, a halotriazine, a hydrazine, an imido ester, an isocyanate, an isothiocyanate, a maleimide, a sulphonyl halide, a thiol, a ketone, an amine which is optionally activated, an acid halide, a succinimidyl ester, a hydroxysuccinimidyl ester, a hydroxysulfosuccinimidyl ester, an azidonitrophenyl, an azidophenyl, a 3-(2-pyridyldithio)-propionamide, a glyoxal, a triazine, and an acetylenic group;
• E is a —CH2—(CH2)s—CH2—SO3— or —(CH2)s—NmAlk1Alk2Alk3 group, or a sulfobetaine of formula
• where R4 represents a (C1-C6)alkyl, and t is equal to 1, 2, 3, 4, 5 or 6;
• r is an integer from 1 to 6;
• s is 0, 1 or 2;
• Alk1, Alk2, Alk3, which may be identical or different, represent a (C1-C6)alkyl.