Patent ID: 7160732

Claim:
A fluorescein-based ligand, comprising a ligand having one of the following structures: wherein, independently for each occurrence: K is optionally present and if present, is any one or more of the following substituents at one or more of the substitutable positions of the indicated aromatic ring: alkyl, alkenyl, alkynyl, amino, acyl, acyloxy, acylamino, alkylthio, alkoxyl, nitro, halogen, sulfhydryl, cyano, hydroxyl, carbamoyl and trifluoromethyl. A is —CH 2 —, —C(═O)—, —C(═S)—, —CH 2 CH 2 —, —CH 2 C(═O)—, —CH 2 C(═S)— or —C(H)═; Z is hydrogen or any hydroxyl-protecting group; Q is O, S or Se; K is optionally present and if present, is any one or more of the following substituents at one or more of the substitutable positions of the indicated aromatic ring: alkyl, alkenyl, alkynyl, amineo, acyl, acyloxy, acylamino, alkylthio, alkoxyl, nitro, halogen, sulfhydryl, cyano, hydroxyl, carbamoyl and trifluoromethyl; V is (i) a chemical moiety comprising at least three Lewis basic moieties each independently selected from the group of Lewis basic moieties consisting of: amino, amido, nitro, nitroso, amino alcohol, nitrile, imino, isonitrile, cyanate, isocyanate, phosphate, phosphonate, phosphite, phosphine, phosphine oxide, phosphorothioate, phosphoramidate, phosphonamidite, hydroxyl, carbonyl, aldehyde, ketone, ether, carbamoyl, thiol, sulfide, thiocarbonyl, thioether, mercaptan, sulfonic acid, sulfoxide, sulfate, sulfonate, sulfone, sulfonamide, sulfamoyl, sulfinyl, or heterocyclyl, wherein the at least three Lewis basic moieties are capable of forming a tridentate chelate and at least one of the Lewis basic moieties is heterocyclyl or (ii) an imino group, wherein said imino group is capable of forming a bidentate chelate; Y is O, S, Se, NR, or C(CH 3 ) 2, wherein R is an alkyl and R and the methyl groups of C(CH 3 ) 2 are optionally substituted; Z2 is N, HOOCCH 2 CH 2 C—, HOOC—CH═CH—C—, (2-carboxyphenyl)-C—, or (2-sulfophenyl)-C—, wherein for said (2-carboxyphenyl)-C— and (2-sulfophenyl)-C—, said phenyl moiety is optionally substituted with one or more E, and wherein for said HOOCCH 2 CH 2 C— and HOOC—CH═CH—C—, said hydrogen atoms of said —CH 2 —'s and —CH═'s moieties are optionally substituted; E is optionally present and if present, is any one or more of the following substituents at one or more of the substitutable positions of the indicated aromatic ring: alkyl, alkenyl, alkynyl, amino, acyl, acyloxy, acylamino, alkylthio, alkoxyl, nitro, halogen, sulfhydryl, cyano, hydroxyl, carbamoyl and trifluoromethyl; and D is —CH 2 CH 2 —or —CH═CH—, wherein said hydrogen atoms are optionally substituted.