Fluorenyl cyanine dyes

A compound of Formula 1a or 1b:

• wherein:
• X1 is O, S, NR1 or CR2R3;
• R1, R2 and R3 are independently substituted or unsubstituted alkyl, (R)p—(L)q—, or R2 and R3 taken together form a 3-8 membered ring optionally substituted by (R)p-(L)q—;
• R4, R5, R6, and R7 are independently hydrogen, halo, —CN, alkoxy, alkyl, aryl, heteroaryl, amino, alkylamino, dialkylamino, alkanecarboxamido, alkanesulfonamido, aminocarbonyl, N-alkylaminocarbonyl, N,N-dialkylaminocarbonyl, N,N,N-trialkylammoniumalkyl, aminosufonyl, N-alkylaminosulfonyl, N,N-dialkylaminosulfonyl, phosphonyl, carboxylate, azide, nitro, arylazo, or (R)p—(L)q—;
• at least one substituent pair of R4 and R5, R5 and R6, or R6 and R7, taken together with the atoms it is attached to, is a substituent pair forming a fused ring system according to Formula 1c:
• where the dashed lines represent the bonds of the substituent pair connecting to Formula 1a or 1b;
• R9 is halo, —CN, alkoxy, alkyl, aryl, heteroaryl, amino, alkylamino, dialkylamino, alkanecarboxamido, alkanesulfonamido, aminocarbonyl, N-alkylaminocarbonyl, N,N-dialkylaminocarbonyl, N,N,N-trialkylammoniumalkyl, aminosufonyl, N-alkylaminosulfonyl, N,N-dialkylaminosulfonyl, phosphonyl, sulfonate, carboxylate, azide, nitro, arylazo, or (R)p—(L)q—;
• a is 0, 1, 2, 3, or 4;
• X2 is CR11R12, where each R11 and R12 is substituted or unsubstituted alkyl, (R)p—(L)q—, or R11 and R12 taken together form a 3-8 membered ring, optionally substituted by (R)p—(L)q—;
• Y is a bridge unit that permits electron delocalization optionally comprising (R)p—(L)q—;
• Q is optionally substituted aryl or heteroaryl;
• R8 is H, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, or (R)p—(L)q—;
• or
• R8 taken together with R7 forms a saturated or unsaturated 5- or 6-membered ring, optionally substituted;
• or
• R8, taken together with a substituent on the moiety Y, forms a 5- or 6-membered saturated or unsaturated ring;
• or
• R8, taken together with a substituent on the moiety Q, forms a macrocycle;
• W is a counter ion;
• c is an integer indicating the number of W such that the overall charge of Formula 1 is zero;
• each R of each (R)p—(L)q— substituent is independently i) a reactive group capable of forming a covalent bond upon reacting with a reaction substrate;
• ii) a water-soluble group;
• or iii) a biopolymer;
• each L of each R)p—(L)q— substituent is independently a linking moiety formed of one or more chemical bonds and containing about 1-100 atoms;
• each p of each R)p—(L)q— is independently an integer of about 1 to about 20;
• each q of each R)p—(L)q— is independently an integer of 0 to about 20;
• and
• the compound of Formula 1a or 1b comprises at least one substituent which is R)p—(L)q—.