Heterocyclyl polymethine IR chromophores

1. A compound of formula I:

wherein:

A and B are independently selected from:

W is O;

Y is O + ;

n is 0, 1, 2, 3, 4, or 5;

each instance of R 6 is independently selected from H, alkyl, fluoroalkyl, sulfonatoalkyl, acyl, cycloalkyl, heterocyclyl, aryl, and heteroaryl;

each instance of R 7 is independently selected from alkyl, alkoxy, acyl, cycloalkyl, heterocyclyl, aryl, heteroaryl, N(R 6 )R 6 , sulfonate, carbonate, cyano, ester, amide, and halo;

each instance of n 1 is 0 or 1;

X is H, halo or is Z—R 4 —N(R 5 )—C(O)O—Y 1 ;

Z is N(R 3 ) or S;

R 1 and R 2 are independently selected from H and alkyl; or R 1 and R 2 together complete a cycloalkenyl ring, a heterocyclyl ring, or a polycyclyl ring system;

R 3 , R 4 , and R 5 are independently selected from alkyl; and

Y 1 is a cargo moiety.

2. The compound of claim 1 , wherein at least one of A and B is not:

3. The compound of claim 1 , wherein the compound is a compound of formula II:

4. The compound of claim 1 , wherein R 1 and R 2 together complete a cycloalkenyl ring.

5. The compound of claim 1 , wherein R 7 is selected from haloalkyl, cyano, sulfonate, sulfonatoalkyl, sulfonatoalkyloxy, carboxyl, ester, amide, halo, nitro, alkylammonium, amine oxide, and haloalkyl.

6. The compound of claim 4 , wherein at least one R 7 is selected from fluoroalkyl.

7. The compound of claim 4 , wherein at least one R 7 is (CH 2 ) 3 C 6 F 13 .

8. The compound of claim 1 , wherein:

A and B are independently selected from:

9. The compound of claim 1 , wherein n is 0.

10. The compound of claim 1 , wherein X is halo or Z—R 4 —N(R 5 )—C(O)O—Y; and R 4 and R 5 are independently selected from alkyl.

11. The compound of claim 1 , wherein at least one of A and B is

12. The compound of claim 1 , wherein at least one of A and B is substituted with N(R 8 )R 9 , wherein R 8 is cycloalkyl, heterocyclyl, aryl, or heteroaryl, and R 9 is selected from H, alkyl, acyl, cycloalkyl, heterocyclyl, aryl, and heteroaryl; or wherein R 8 and R 9 together complete a heterocyclyl.

13. The compound of claim 1 , wherein at least one of A and B is substituted with a 4-8 member N-linked heteroaryl or heterocyclyl.

14. The compound of claim 1 , wherein at least one of A and B is substituted with sulfate, sulfonate, sulfonatoalkyl, or carboxylate.

15. A pharmaceutical composition comprising a compound of claim 1 and at least one pharmaceutically acceptable excipient.

16. A method of obtaining an image comprising:

illuminating a compound of claim 1 with excitation light, thereby causing the compound to emit fluorescence; and

detecting the fluorescence.

17. A method of preparing a compound of claim 1 comprising:

providing a starting material compound of formula I wherein A and B are the same:

contacting the starting material compound with a basic amine, thereby producing a half-dye intermediate;

providing a compound of formula (IV):

R 8 -D  (IV); and

contacting the half-dye intermediate with the compound of formula (IV), thereby producing the compound;

wherein:

A and B are independently selected from a bicyclic, tricyclic, and tetracyclic heteroaryl;

A and B are different;

each instance of n is 0 or 1;

X is H, halo or is Z—R 4 —N(R 5 )—C(O)O—Y 1 ;

Z is N(R 3 ) or S;

R 1 and R 2 are independently selected from H and alkyl; or R 1 and R 2 together complete a cycloalkenyl ring, a heterocyclyl ring, or a polycyclyl ring system;

R 3 , R 4 , and R 5 are independently selected from alkyl;

R 8 is alkyl; and

Y 1 is a cargo moiety.

18. The compound of claim 1 , wherein the compound is