Salicylamide-lanthanide complexes for use as luminescent markers

A luminescent complex formed between a lanthanide ion and a compound having a structure according to Formula I:

• wherein,
• R1 and R2 are members independently selected from the group consisting of alkyl, substituted alkyl, polyether, substituted polyether, halogen and —OR6, wherein
• R6 is a member selected from the group consisting of H, alkyl, substituted alkyl groups, polyether, substituted polyether, and a single negative charge;
• R4, R5, R7, R10 and R20 are members independently selected from the group consisting of H, polyether, substituted polyether, alkyl and substituted alkyl groups;
• R3, R6 and R9 are members independently selected from the group consisting of polyether, substituted polyether, alkyl and substituted alkyl groups;
• R11, R12, R13, R21, R22 and R23 are members independently selected from alkyl, substituted alkyl, H, —NR14R15, —NO2, —OR16, —COOR17,
• wherein, R14, R15, R16 and R17 are members independently selected from the group consisting of H, alkyl and substituted alkyl, wherein R12 can optionally form a ring with R11, R13 or both, and R22 can optionally form a ring with R21, R23 or both, said rings being members independently selected from the group of ring systems consisting of cyclic alkyl, substituted cyclic alkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclyl and substituted heterocyclyl ring systems;
• and
• Q1 is —OR18;
• Q2 is —OR19,
• wherein R18 and R19 are members independently selected from H, an enzymatically labile group, a hydrolytically labile group and a single negative charge;
• and
• a and z are independently selected from the group consisting of 0 and 1, with the proviso that when a is 0, N1′ is covalently attached directly to carbonyl 1′, and when z is 0, N2′ is covalently attached directly to carbonyl group 2′.