4,4-disubstituted cyclohexyl bridged heptamethine cyanine dyes and uses thereof

A fluorescent compound represented by Formula I-B:

• or a salt thereof, wherein:
• X1 and X2 are each independently O, S, Se, or C(C1-4 alkyl)2;
• W1 and W2 are a benzo, naphtha, or pyridyl ring;
• R1 and R2 are independently hydrogen or —C1-C10 alkyl optionally substituted with one or two substituents independently selected from the group consisting of halogen, —SO3H, —SO3−, —COOH, —CO2−, and —OH;
• R5 and R7 are each independently hydrogen or —C1-C22 alkylene-X3;
• R3, R4, R13 and R14 are each independently hydrogen, —C1-C22 alkylene-X3, —SO3H, —SO3−, —SO2N(R12)-alkylene-X3, halogen, or —NO2;
• X3 represents independently for each occurrence H, halogen, —CH3, —SO3H, —SO3−, —COOH, —CO2−, —NCS, —NCO, N-hydroxysuccinimidyl ester, N-hydroxysulfosuccinimidyl ester, —OH, —SH, maleimide, phthalimide, —NHCO—(CH2)m-(halogen), —CONHNH2, —CN, —NH2, —NO2, —CON(H)R12, alkynyl, —N3, a polyethyl glycol, optionally substituted aryl, or optionally substituted heterocyclyl;
• R9 and R10 are H, halogen, or alkyl, or R1 and R9 or R2 and R10 are taken together with their interconnecting atoms to form a 5-, 6- or 7-membered ring;
• R11 is —COOH, —CN, halogen, —NO2, —C(O)-haloalkyl, haloalkyl, —COOR15, —CON(H)R15, or —CO(CH2)nR15;
• R12 represents independently for each occurrence hydrogen or alkyl;
• R15 is H, —COOH, —SO3H, —NH2, —SH, alkyl, or aryl optionally substituted with X3 and/or a polyethylene glycol;
• m represents independently for each occurrence 0, 1, 2, 3, or 4;
• and
• n represents independently for each occurrence 1-10.