Photoinduced electron transfer voltage-sensitive compounds

1. A compound comprising the structure of Formula II:

wherein,

L 1 is selected from the group consisting of:

and any combination of the foregoing;

A 1 , A 4 -A 10 are each independently selected from CH 2 , CHR′, CR′ 2 , NH, O, S, Se, Te, SiH 2 , SiHR′, SiR′ 2 , GeH 2 , GeHR′, GeR′ 2 , SnH 2 , SnHR′, SnR′ 2 , PbH 2 , PbHR′, or PbHR′ 2 , wherein R′ is selected from the group consisting of D, optionally substituted FG, optionally substituted (C 1 -C 12 )alkyl, optionally substituted (C 1 -C 11 )heteroalkyl, optionally substituted (C 1 -C 12 )alkenyl, optionally substituted (C 1 -C 11 )heteroalkenyl, optionally substituted (C 1 -C 12 )alkynyl, and optionally substituted (C 1 -C 11 )heteroalkynyl;

A 2 is selected from NH 2 , S or O;

A 3 is selected from NH 2 , OH, SH and methoxy;

X 1 -X 39 are independently selected from N or C, wherein when an X group is an N, then the R group is absent; and

R 1 -R 3 , R 5 -R 6 , R 8 -R 10 , R 12 , and R 14 -R 47 are independently selected from H, D, optionally substituted FG, optionally substituted (C 1 -C 12 )alkyl, optionally substituted (C 2 -C 10 )heteroalkyl, optionally substituted (C 1 -C 12 )alkenyl, optionally substituted (C 2 -C 10 )heteroalkenyl, optionally substituted (C 1 -C 12 )alkynyl, optionally substituted (C 2 -C 10 )heteroalkynyl, optionally substituted (C 3 -C 12 )cycloalkyl, optionally substituted (C 5 -C 12 )cycloalkenyl, optionally substituted aryl, optionally substituted heterocycle, optionally substituted mixed ring system, wherein one or more adjacent R groups can be linked together to form one or more substituted rings selected from the group comprising (C 3 -C 12 )cycloalkyl, (C 3 -C 12 )cycloalkenyl, heterocycle, aryl, and mixed ring system;

wherein R 4 and R 7 are F or Cl;

R 11 is selected from NH 2 , NH(R 50 ), N(R 50 ) 2 wherein R 50 is a (C 1 -C 3 )alkyl;

wherein R 13 is an alkoxy; and

n 1 -n 8 are independently an integer selected from 0 to 10.

2. The compound of claim 1 , wherein the compound comprises the structure of Formula III:

wherein,

A 1 is selected from CH 2 , CHR′, CR′ 2 , NH, O, S, Se, Te, SiH 2 , SiHR′, SiR′ 2 , GeH 2 , GeHR′, GeR′ 2 , SnH 2 , SnHR′, SnR′ 2 , PbH 2 , PbHR′, or PbHR′ 2 , wherein R′ is selected from the group consisting of D, optionally substituted FG, optionally substituted (C 1 -C 12 )alkyl, optionally substituted (C 2 -C 10 )heteroalkyl, optionally substituted (C 1 -C 12 )alkenyl, optionally substituted (C 2 -C 10 )heteroalkenyl, optionally substituted (C 1 -C 12 )alkynyl, and optionally substituted (C 2 -C 10 )heteroalkynyl,

A 2 is NH 2 or O;

A 3 is selected from NH 2 , OH and methoxy;

X 1 -X 17 are independently selected from N or C, wherein when an X group is an N, then the R group is absent; and

R 1 -R 3 , R 5 -R 6 , R 8 -R 10 , R 12 , and R 14 -R 21 are independently selected from H, D, optionally substituted FG, optionally substituted (C 1 -C 12 )alkyl, optionally substituted (C 2 -C 10 )heteroalkyl, optionally substituted (C 1 -C 12 )alkenyl, optionally substituted (C 2 -C 10 )heteroalkenyl, optionally substituted (C 1 -C 12 )alkynyl, optionally substituted (C 2 -C 10 )heteroalkynyl, optionally substituted (C 3 -C 12 )cycloalkyl, optionally substituted (C 5 -C 12 )cycloalkenyl, optionally substituted aryl, optionally substituted heterocycle, optionally substituted mixed ring system, wherein one or more adjacent R groups can be linked together to form one or more substituted rings selected from the group comprising (C 3 -C 12 )cycloalkyl, (C 3 -C 12 )cycloalkenyl, heterocycle, aryl, and mixed ring system;

wherein R 4 and R 7 are F or Cl;

R 11 is selected from NH 2 , NH(R 50 ), N(R 50 ) 2 wherein R 50 is a (C 1 -C 3 )alkyl;

wherein R 13 is an alkoxy; and

n 1 is an integer selected from 0 to 10.

3. The compound of claim 2 , wherein the compound comprises the structure of Formula III(a):

wherein,

A 1 is selected from CH 2 , CHR′, CR′ 2 , NH, O, S, Se, Te, SiH 2 , SiHR′, SiR′ 2 , GeH 2 , GeHR′, GeR′ 2 , SnH 2 , SnHR′, SnR′ 2 , PbH 2 , PbHR′, or PbHR′ 2 , wherein R′ is selected from the group consisting of D, optionally substituted FG, optionally substituted (C 1 -C 6 )alkyl, optionally substituted (C 2 -C 5 )heteroalkyl, optionally substituted (C 1 -C 6 )alkenyl, optionally substituted (C 2 -C 5 )heteroalkenyl, optionally substituted (C 1 -C 6 )alkynyl, and optionally substituted (C 2 -C 5 )heteroalkynyl,

A 2 is NH 2 or O;

A 3 is NH 2 or OH;

R 4 and R 7 are independently F, and/or Cl;

R 11 is selected from NH 2 , NH(R 50 ), N(R 50 ) 2 , wherein R 50 is a (C 1 -C 3 )alkyl;

R 13 is an alkoxy; and

n 1 is an integer selected from 0 to 5.

4. The compound of claim 3 , wherein the compound comprises the structure of Formula III(b):

wherein,

R 4 and R 7 are independently F, and/or Cl;

R 11 is selected from NH 2 , NH(R 50 ), N(R 50 ) 2 , wherein R 50 is a (C 1 -C 3 )alkyl; and

R 13 is a methoxy.

5. The compound of claim 1 , wherein the compound has one or more of the following characteristics:

the compound is water soluble;

the compound exhibits a tilt angle from 0° to 20°;

the compound exhibits a voltage sensitivity of 63% ΔF/F per 100 mV or greater; and

the compound can undergo photoinduced electron transfer.

6. The compound of claim 5 , wherein the compound is characterized by being water soluble; exhibits a tilt angle of about 0°; exhibits a voltage sensitivity of 63% ΔF/F per 100 mV or greater; and can undergo photoinduced electron transfer.

7. A method to image cells, comprising:

contacting the cell with a compound of claim 1 ;

illuminating the cells with light having a first wavelength;

imaging the cells by detecting light having a second wavelength,

wherein the first wavelength and second wavelength of light have different wavelengths, and wherein the light having the second wavelength is in the far red to near infrared region.

8. The method of claim 7 , wherein the method further comprises:

contacting the cells with one or more additional optogenetic tools; and

imaging the cells be detecting light emissions at one or more additional wavelengths.

9. The method of claim 8 , wherein the one or more optogenetic tools are selected from GFP, Ca 2+ indicators, voltage sensors based on cpGFP, and ChannelRhodopsin2 (ChR2).

10. A method to measure changes in membrane potential in an excitable cell comprising:

contacting the excitable cell with a compound of claim 1 ;

stimulating the cell to evoke action potentials; and

measuring action potential firing by optical or electrical sampling.

11. The method of claim 10 , wherein the optical sampling is measured using an electron multiplying charge couple device.

12. The method of claim 11 , wherein the excitable cell is stimulated using a whole-cell current clamp or by field stimulation.

13. The method of claim 10 , wherein the excitable cell is a neuron, cardiomyocyte, myocyte, or a secretory cell.

14. The method of claim 13 , wherein the method interrogates membrane potentials of a neuron.

15. A kit comprising:

a plurality of compartments which comprise a compound of claim 1 in a buffered solution, or a concentrated solution.