Compositions and methods and uses relating thereto

1. A compound of formula (I):

wherein p is 2 or 4, n is at least 1 and less than or equal to p; Ar is a polycyclic aromatic moiety based on a fluorene, anthracene or pyrene moiety, or an isomer thereof, R 1 is hydrogen or an unsubstituted alkyl, alkenyl or aralkyl group and each of R 2 , R 3 and R 4 is independently an unsubstituted alkyl, alkenyl or aralkyl group, provided that at least one of R 2 , R 3 and R 4 has at least 6 carbon atoms.

2. A method of preparing a compound of formula (I):

the method comprising admixing (a) a quaternary ammonium salt, a tertiary amine or a tertiary amine salt with (b) a sulfonated polycyclic aromatic compound; wherein p is 2 or 4, n is at least 1 and less than or equal to p; Ar is a polycyclic aromatic moiety based on a fluorene, anthracene or pyrene moiety, or an isomer thereof, R 1 is hydrogen or an unsubstituted alkyl, alkenyl or aralkyl group and each of R 2 , R 3 and R 4 is independently an unsubstituted alkyl, alkenyl or aralkyl group, provided that at least one of R 2 , R 3 and R 4 has at least 6 carbon atoms.

3. The method of preparing a compound of formula (I) according to claim 2 , wherein component (a) comprises a quaternary ammonium salt or a tertiary amine salt, and the method involves admixing a compound of formula (III):

and compound of formula (IV):

Ar SO 3 − ] p [X + ] p   (IV)

wherein Ar is a polycyclic aromatic moiety based on a fluorene, anthracene or pyrene moiety, or an isomer thereof, p is 2 or 4, X + is a proton, an ammonium ion or a metal ion, R 1 is hydrogen or an unsubstituted alkyl, alkenyl or aralkyl group, each of R 2 , R 3 and R 4 is independently an unsubstituted alkyl, alkenyl or aralkyl group, provided that at least one of R 2 , R 3 and R 4 has at least 6 carbon atoms and Y − is an anion.

4. A composition comprising a compound of formula (I):

wherein p is 2 or 4, n is at least one and is less than or equal to p; Ar is a polycyclic aromatic moiety based on a fluorene, anthracene or pyrene moiety, or an isomer thereof, R 1 is hydrogen or an unsubstituted alkyl, alkenyl or aralkyl group and each of R 2 , R 3 and R 4 is independently an unsubstituted alkyl, alkenyl or aralkyl group, provided that at least one of R 2 , R 3 and R 4 has at least 6 carbon atoms.

5. The composition according to claim 4 , wherein said composition is an additive composition for a fuel and said composition further comprises one or more fuel additives.

6. A fuel composition comprising a fuel, one or more additives and a compound of formula (I):

wherein p is at least 1, n is at least 1 and is less than or equal to p; Ar is a polycyclic aromatic moiety, R 1 is hydrogen or an optionally substituted hydrocarbyl group and each of R 2 , R 3 and R 4 is independently an optionally substituted hydrocarbyl group, provided that at least one of R 2 , R 3 and R 4 has at least 6 carbon atoms.

7. The fuel composition according to claim 6 wherein the fuel comprises gasoline, ethanol or mixtures thereof.

8. The fuel composition according to claim 6 wherein the fuel comprises diesel.

9. A method of preparing a fuel composition, the method comprising:

preparing an additive composition comprising a compound of formula (I):

wherein p is at least 1, n is at least 1 and is less than or equal to p; Ar is a polycyclic aromatic moiety, R 1 is hydrogen or an optionally substituted hydrocarbyl group and each of R 2 , R 3 and R 4 is independently an optionally substituted hydrocarbyl group, provided that at least one of R 2 , R 3 and R 4 has at least 6 carbon atoms; and

dosing said additive composition into a fuel.

10. The method according to claim 9 wherein said dosing step comprises dosing said additive composition into an ethanol component of a fuel composition; and wherein said method further comprises blending said ethanol component with a gasoline fuel.

11. A method of determining the presence of an additive in a fuel composition comprising said additive and a compound of formula (I):

wherein p is at least 1, n is at least 1 and is less than or equal to p; Ar is a polycyclic aromatic moiety, R 1 is hydrogen or an optionally substituted hydrocarbyl group and each of R 2 , R 3 , and R 4 is independently an optionally substituted hydrocarbyl group, provided that at least one of R 2 , R 3 and R 4 has at least 6 carbon atoms, the method comprising applying electromagnetic radiation having a first wavelength to said fuel composition; and determining the emission of electromagnetic radiation from the compound of formula (I) at a second wavelength.

12. A method of determining the concentration of a first additive in a fuel composition comprising said first additive and a compound of formula (I):

wherein p is at least 1, n is at least 1 and is less than or equal to p; Ar is a polycyclic aromatic moiety, R 1 is hydrogen or an optionally substituted hydrocarbyl group and each of R 2 , R 3 and R 4 is independently an optionally substituted hydrocarbyl group, provided that at least one of R 2 , R 3 and R 4 has at least 6 carbon atoms, the compound of formula (I) being present in the fuel composition at a concentration that is proportional to the concentration of the first additive; the method comprising: applying electromagnetic radiation having a first wavelength to said fuel composition; measuring emission of electromagnetic radiation from the compound of formula (I) at a second wavelength; and calculating from the level of emission at said second wavelength the concentration of the first additive in the fuel composition.

13. A method of determining the concentration of an additive composition that has been dosed into a fuel composition, wherein the additive composition comprises a compound of formula (I):

wherein p is at least 1, n is at least 1 and is less than or equal to p; Ar is a polycyclic aromatic moiety, R 1 is hydrogen or an optionally substituted hydrocarbyl group and each of R 2 , R 3 and R 4 is independently an optionally substituted hydrocarbyl group, provided that at least one of R 2 , R 3 and R 4 has at least 6 carbon atoms and at least one further additive; the method comprising: applying electromagnetic radiation having a first wavelength to said fuel composition; measuring emission of electromagnetic radiation from the compound of formula (I) at a second wavelength; and calculating from the level of emission at said second wavelength the concentration of the compound of formula (I) in the fuel composition.

14. The composition according claim 4 wherein R 1 is hydrogen or an alkyl, alkenyl or alkaryl group having 1 to 12 carbon atoms and each of R 2 , R 3 and R 4 is an alkyl, alkenyl or alkaryl group having 1 to 36 carbon atoms, provided that that at least one of R 2 , R 3 and R 4 has at least 6 carbon atoms.

15. The composition according claim 4 wherein R 1 is hydrogen or an alkyl group having 1 to 4 carbon atoms, R 2 is benzyl or an alkyl group having 1 to 4 carbon atoms, and each of R 3 and R 4 is an alkyl, alkenyl or alkaryl group having 1 to 36 carbon atoms, provided that that at least one of R 3 and R 4 has at least 6 carbon atoms.

16. The composition according claim 4 wherein R 1 , R 2 , R 3 and R 4 together comprise in total from 16 to 40 carbon atoms, preferably from 20 to 36 carbon atoms, for example from 20 to 30 carbon atoms.

17. The composition according claim 4 wherein each of R 1 , R 2 , R 3 and R 4 is an unsubstituted alkyl or alkenyl group; and each of R 3 and R 4 has at least 6 carbon atoms.

18. The composition according claim 4 wherein R 1 is hydrogen or an unsubstituted alkyl group having 1 to 4 carbon atoms; R 2 is an unsubstituted alkyl group having 1 to 4 carbon atoms or an unsubstituted alkyl or alkenyl group having 6 to 36 carbon atoms, preferably 8 to 30 carbon atoms; R 3 is benzyl, an unsubstituted alkyl group having 1 to 4 carbon atoms or an unsubstituted alkyl or alkenyl group having 6 to 36 carbon atoms, preferably 8 to 30 carbon atoms; and R 4 is an unsubstituted alkyl or alkenyl group having 6 to 36 carbon atoms, preferably 8 to 30 carbon atoms.

19. The composition according claim 4 wherein n is from 1 to 4.

20. The composition according claim 4 wherein the compound of formula (I) has the structure (II):

or an isomer thereof.

21. A kit for determining the concentration of a compound of formula (I) in a fuel composition, the kit comprising means for applying electromagnetic radiation having a first wavelength to said fuel composition; and means for measuring emission of electromagnetic radiation at a second wavelength.