Precursor compounds for molecular coatings

1. A composition comprising:

(i) one or more compounds of Formula II:

and

(ii) one or more compounds of Formula I:

wherein the composition comprises at least 90% by mass of the one or more compounds of Formula II and the one or more compounds of Formula I, and for both Formula I and Formula II:

each R a is independently —H or —C 1 -C 6 alkyl;

each R b is independently selected from —H, —C 1 -C 6 alkyl, or —OH;

R 1 , R 2 , R 5 , R 6 , R 9 , R 10 , R 11 , R 12 and R 13 are each independently, at each occurrence, —H, —OR 14 , —NR 14 R 15 , —SR 14 , halogen, —C 1 -C 6 alkyl, —C 2 -C 6 alkenyl, —C 2 -C 6 alkynyl, —C 3 -C 7 cycloalkyl, aryl, or heteroaryl, wherein each alkyl, alkenyl, alkynyl, cycloalkyl, aryl, or heteroaryl is optionally substituted with one or more —OR 14 , —NR 14 R 15 , —SR 14 , or halogen;

R 3 , R 4 , R 7 , and R 8 are each independently, at each occurrence, —H, —OR 14 , —NR 14 R 15 , —SR 14 , halogen, —C 1 -C 6 alkyl, —C 2 -C 6 alkenyl, —C 2 -C 6 alkynyl, —C 3 -C 7 cycloalkyl, aryl, or heteroaryl wherein each alkyl, alkenyl, alkynyl, cycloalkyl, aryl, or heteroaryl is optionally substituted with one or more —OR 14 , —NR 14 R 15 , —SR 14 , or halogen; or

R 3 and R 4 can combine with the carbon atoms to which they are attached to form a C 3 -C 6 cycloalkyl, a C 4 -C 6 cycloalkenyl, or 3- to 6-membered ring heterocycle; and/or

R 7 and R 8 can combine with the carbon atoms to which they are attached to form a C 3 -C 6 cycloalkyl, a C 4 -C 6 cycloalkenyl, or 3- to 6-membered ring heterocycle;

R 14 and R 15 are each independently, at each occurrence, —H, —C 1 -C 6 alkyl, —C 2 -C 6 alkenyl, or —C 2 -C 6 alkynyl;

the symbol represents a single bond or a cis or trans double bond;

n is 0, 1, 2, 3, 4, 5, 6, 7 or 8;

m is 0, 1, 2 or 3;

q is 0, 1, 2, 3, 4 or 5; and

r is 0, 1, 2, 3, 4, 5, 6, 7 or 8.

2. The composition of claim 1 , further comprising an additive selected from fatty acids, esters, amides, amines, thiols, carboxylic acids, ethers, aliphatic waxes, alcohols, organic salts, and inorganic salts, wherein the additive is different from the one or more compounds of Formula II and the one or more compounds of Formula I.

3. The composition of claim 1 , wherein a carbon chain length of one or more of the compounds of Formula II is different from a carbon chain length of one or more of the compounds of Formula I.

4. The composition of claim 1 , wherein the one or more compounds of Formula II comprise one or more of 2,3-dihydroxypropan-1-yl octadecanoate, 2,3-dihydroxypropan-1-yl tetradecanoate, and 2,3-dihydroxypropan-1-yl (9Z)-octadecenoate.

5. The composition of claim 2 , wherein the additive is an organic salt.

6. The composition of claim 1 , wherein the composition comprises less than about 10% by mass of proteins, polysaccharides, phenols, lignans, aromatic acids, terpenoids, flavonoids, carotenoids, alkaloids, alcohols, alkanes, and aldehydes.

7. The composition of claim 1 , wherein the composition is a solid at 25° C. and 1 atmosphere of pressure.

8. The composition of claim 7 , wherein the solid includes crystals having an average diameter less than about 2 millimeters.

9. The composition of claim 1 , further comprising one or more fatty acids.

10. A mixture comprising a composition in a solvent, the composition comprising:

(i) one or more compounds of Formula II:

and

(ii) one or more compounds of Formula I:

wherein the composition comprises at least 90% by mass of the one or more compounds of Formula II and the one or more compounds of Formula I, and for both Formula I and Formula II:

each R a is independently —H or —C 1 -C 6 alkyl;

each R b is independently selected from —H, —C 1 -C 6 alkyl, or —OH;

R 1 , R 2 , R 5 , R 6 , R 9 , R 10 , R 11 , R 12 and R 13 are each independently, at each occurrence, —H, —OR 14 , —NR 14 R 15 , —SR 14 , halogen, —C 1 -C 6 alkyl, —C 2 -C 6 alkenyl, —C 2 -C 6 alkynyl, —C 3 -C 7 cycloalkyl, aryl, or heteroaryl, wherein each alkyl, alkenyl, alkynyl, cycloalkyl, aryl, or heteroaryl is optionally substituted with one or more —OR 14 , —NR 14 R 15 , —SR 14 , or halogen;

R 3 , R 4 , R 7 , and R 8 are each independently, at each occurrence, —H, —OR 14 , —NR 14 R 15 , —SR 14 , halogen, —C 1 -C 6 alkyl, —C 2 -C 6 alkenyl, —C 2 -C 6 alkynyl, —C 3 -C 7 cycloalkyl, aryl, or heteroaryl wherein each alkyl, alkenyl, alkynyl, cycloalkyl, aryl, or heteroaryl is optionally substituted with one or more —OR 14 , —NR 14 R 15 , —SR 14 , or halogen; or

R 3 and R 4 can combine with the carbon atoms to which they are attached to form a C 3 -C 6 cycloalkyl, a C 4 -C 6 cycloalkenyl, or 3- to 6-membered ring heterocycle; and/or

R 7 and R 8 can combine with the carbon atoms to which they are attached to form a C 3 -C 6 cycloalkyl, a C 4 -C 6 cycloalkenyl, or 3- to 6-membered ring heterocycle;

R 14 and R 15 are each independently, at each occurrence, —H, —C 1 -C 6 alkyl, —C 2 -C 6 alkenyl, or —C 2 -C 6 alkynyl;

the symbol represents a single bond or a cis or trans double bond;

n is 0, 1, 2, 3, 4, 5, 6, 7 or 8;

m is 0, 1, 2 or 3;

q is 0, 1, 2, 3, 4 or 5; and

r is 0, 1, 2, 3, 4, 5, 6, 7 or 8.

11. The mixture of claim 10 , further comprising an additive selected from fatty acids, esters, amides, amines, thiols, carboxylic acids, ethers, aliphatic waxes, alcohols, organic salts, and inorganic salts, wherein the additive is different from the one or more compounds of Formula II and the one or more compounds of Formula I.

12. The mixture of claim 10 , wherein at least one compound of the one or more compounds of Formula II is selected from 2,3-dihydroxypropan-1-yl octadecanoate, 2,3-dihydroxypropan-1-yl palmitate, and 2,3-dihydroxypropan-1-yl tetradecanoate.

13. A method of forming a coating on a substrate, the method comprising:

(i) providing a mixture comprising a composition in a solvent, the composition comprising:

(a) one or more compounds of Formula II:

and

(b) one or more compounds of Formula I:

wherein the composition comprises at least 90% by mass of the one or more compounds of Formula II and the one or more compounds of Formula I, and for both Formula I and Formula II:

each R a is independently —H or —C 1 -C 6 alkyl;

each R b is independently selected from —H, —C 1 -C 6 alkyl, or —OH;

R 1 , R 2 , R 5 , R 6 , R 9 , R 10 , R 11 , R 12 and R 13 are each independently, at each occurrence, —H, —OR 14 , —NR 14 R 15 , —SR 14 , halogen, —C 1 -C 6 alkyl, —C 2 -C 6 alkenyl, —C 2 -C 6 alkynyl, —C 3 -C 7 cycloalkyl, aryl, or heteroaryl, wherein each alkyl, alkenyl, alkynyl, cycloalkyl, aryl, or heteroaryl is optionally substituted with one or more —OR 14 , —NR 14 R 15 , —SR 14 , or halogen;

R 3 , R 4 , R 7 , and R 8 are each independently, at each occurrence, —H, —OR 14 , —NR 14 R 15 , —SR 14 , halogen, —C 1 -C 6 alkyl, —C 2 -C 6 alkenyl, —C 2 -C 6 alkynyl, —C 3 -C 7 cycloalkyl, aryl, or heteroaryl wherein each alkyl, alkenyl, alkynyl, cycloalkyl, aryl, or heteroaryl is optionally substituted with one or more —OR 14 , —NR 14 R 15 , —SR 14 , or halogen; or

R 3 and R 4 can combine with the carbon atoms to which they are attached to form a C 3 -C 6 cycloalkyl, a C 4 -C 6 cycloalkenyl, or 3- to 6-membered ring heterocycle; and/or

R 7 and R 8 can combine with the carbon atoms to which they are attached to form a C 3 -C 6 cycloalkyl, a C 4 -C 6 cycloalkenyl, or 3- to 6-membered ring heterocycle;

R 14 and R 15 are each independently, at each occurrence, —H, —C 1 -C 6 alkyl, —C 2 -C 6 alkenyl, or —C 2 -C 6 alkynyl;

the symbol represents a single bond or a cis or trans double bond;

n is 0, 1, 2, 3, 4, 5, 6, 7 or 8;

m is 0, 1, 2 or 3;

q is 0, 1, 2, 3, 4 or 5; and

r is 0, 1, 2, 3, 4, 5, 6, 7 or 8;

(ii) applying the mixture to a surface of the substrate; and

(iii) causing the composition to solidify on the surface to form the coating.

14. The method of claim 13 , wherein at least one of the one or more compounds of Formula II is selected from 2,3-dihydroxypropan-2-yl octadecanoate, 2,3-dihydroxypropan-2-yl tetradecanoate, and 2,3-dihydroxypropan-2-yl (9Z)-octadecenoate.

15. The method of claim 13 , wherein the mixture further comprises an organic or inorganic salt.

16. The method of claim 13 , wherein the mixture further comprises a carboxylic acid.

17. The method of claim 13 , wherein the solvent comprises water or ethanol.

18. The method of claim 17 , wherein the solvent is at least about 25% water by volume.

19. The method of claim 13 , wherein the coating has a thickness greater than about 0.1 microns.

20. The method of claim 19 , wherein the coating has an average transmittance of at least 60% for light in the visible range.

21. The method of claim 13 , wherein causing the composition to solidify on the surface comprises removing the solvent to precipitate the composition.

22. An agricultural product having a protective coating formed over a surface thereof, the protective coating being formed from a composition comprising:

(i) one or more compounds of Formula II:

and

(ii) one or more compounds of Formula I:

wherein the composition comprises at least 90% by mass of the one or more compounds of Formula II and the one or more compounds of Formula I, and for both Formula I and Formula II:

each R a is independently —H or —C 1 -C 6 alkyl;

each R b is independently selected from —H, —C 1 -C 6 alkyl, or —OH;

R 1 , R 2 , R 5 , R 6 , R 9 , R 10 , R 11 , R 12 and R 13 are each independently, at each occurrence, —H, —OR 14 , —NR 14 R 15 , —SR 14 , halogen, —C 1 -C 6 alkyl, —C 2 -C 6 alkenyl, —C 2 -C 6 alkynyl, —C 3 -C 7 cycloalkyl, aryl, or heteroaryl, wherein each alkyl, alkenyl, alkynyl, cycloalkyl, aryl, or heteroaryl is optionally substituted with one or more —OR 14 , —NR 14 R 15 , —SR 14 , or halogen;

R 3 , R 4 , R 7 , and R 8 are each independently, at each occurrence, —H, —NR 14 R 15 , —SR 14 , halogen, —C 1 -C 6 alkyl, —C 2 -C 6 alkenyl, —C 2 -C 6 alkynyl, —C 3 -C 7 cycloalkyl, aryl, or heteroaryl wherein each alkyl, alkenyl, alkynyl, cycloalkyl, aryl, or heteroaryl is optionally substituted with one or more —OR 14 , —NR 14 R 15 , —SR 14 , or halogen; or

R 3 and R 4 can combine with the carbon atoms to which they are attached to form a C 3 -C 6 cycloalkyl, a C 4 -C 6 cycloalkenyl, or 3- to 6-membered ring heterocycle; and/or

R 7 and R 8 can combine with the carbon atoms to which they are attached to form a C 3 -C 6 cycloalkyl, a C 4 -C 6 cycloalkenyl, or 3- to 6-membered ring heterocycle;

R 14 and R 15 are each independently, at each occurrence, —H, —C 2 -C 6 alkenyl, or —C 2 -C 6 alkynyl;

the symbol represents a single bond or a cis or trans double bond;

n is 0, 1, 2, 3, 4, 5, 6, 7 or 8;

m is 0, 1, 2 or 3;

q is 0, 1, 2, 3, 4 or 5; and

r is 0, 1, 2, 3, 4, 5, 6, 7 or 8; and

wherein the protective coating reduces a mass loss rate of the agricultural product.

23. The agricultural product of claim 22 , wherein the composition is precipitated from a solution to form the protective coating.

24. The agricultural product of claim 22 , wherein the agricultural product is a fruit.

25. The agricultural product of claim 22 , wherein at least one of the compounds of Formula II is selected from 2,3-dihydroxypropan-1-yl palmitate and 2,3-dihydroxypropan-1-yl octadecanoate.

26. The composition of claim 1 , wherein:

(i) the composition comprises about 25% by mass of the one or more compounds of Formula II and about 75% by mass of the one or more compounds of Formula I; or

(ii) the composition comprises about 50% by mass of the one or more compounds of Formula II and about 50% by mass of the one or more compounds of Formula I; or

(iii) the composition comprises about 75% by mass of the one or more compounds of Formula II and about 25% by mass of the one or more compounds of Formula I; or

(iv) the composition comprises about 30% by mass of the one or more compounds of Formula II and about 70% by mass of the one or more compounds of Formula I; or

(v) the composition comprises about 45% by mass of the one or more compounds of Formula II and about 45% by mass of the one or more compounds of Formula I.

27. The composition of claim 1 , wherein:

each R b is —H;

R 1 , R 2 , R 5 , R 6 , R 9 , R 10 , R 11 , R 12 and R 13 are each independently, at each occurrence, —H, —OR 14 , —C 1 -C 6 alkyl, or —C 2 -C 6 alkenyl;

R 3 , R 4 , R 7 , and R 8 are each independently, at each occurrence, —H, —OR 14 , —C 1 -C 6 alkyl, or —C 2 -C 6 alkenyl; or

R 3 and R 4 can combine with the carbon atoms to which they are attached to form a 3- to 6-membered ring heterocycle; and/or

R 7 and R 8 can combine with the carbon atoms to which they are attached to form a 3- to 6-membered ring heterocycle; and

R 14 and R 15 are each independently, at each occurrence, —H or —C 1 -C 6 alkyl.

28. The composition of claim 1 , wherein the molar ratio of the one or more compounds of Formula II to the one or more compounds of Formula I is 3 or greater.

29. The composition of claim 1 , wherein the composition comprises at least 90% by mass of the one or more compounds of Formula II.

30. The composition of claim 29 , wherein the composition comprises at least 95% by mass of the one or more compounds of Formula II.

31. The composition of claim 1 , wherein the composition comprises at least 90% by mass of the one or more compounds of Formula I.

32. The composition of claim 31 , wherein the composition comprises at least 95% by mass of the one or more compounds of Formula I.