Melt-castable energetic compounds comprising oxadiazoles and methods of production thereof

1. A melt-castable energetic material, comprising at least one of:

3,5-bis(4-nitro-1,2,5-oxadiazol-3-yl)-1,2,4-oxadiazole (DNFO); and

3-(4-amino-1,2,5-oxadiazol-3-yl)-5-(4-nitro-1,2,5-oxadiazol-3-yl)-1,2,4-oxadiazole (ANFO),

wherein DNFO has a chemical structure of:

and

wherein ANFO has a chemical structure of:

2. The melt-castable energetic material as recited in claim 1 , comprising both ANFO and DNFO.

3. The melt-castable energetic material as recited in claim 1 , further comprising a metal selected from a group consisting of: aluminum, boron, and magnesium.

4. An article, comprising:

a housing for directing an explosion; and

the melt-castable energetic material as recited in claim 1 for providing the explosion.

5. The article as recited in claim 4 , wherein the melt-castable energetic material further comprises a zero valence metal.

6. A method for forming the melt-castable energetic material as recited in claim 1 , the method comprising:

reacting 3,5-bis(4-amino-1,2,5-oxadiazol-3-yl)-1,2,4-oxadiazole (DAFO) with oxygen or an oxygen-containing compound to form a mixture of at least:

the 3,5-bis(4-nitro-1,2,5-oxadiazol-3-yl)-1,2,4-oxadiazole (DNFO); and

the 3-(4-amino-1,2,5-oxadiazol-3-yl)-5-(4-nitro-1,2,5-oxadiazol-3-yl)-1,2,4-oxadiazole (ANFO),

wherein the DNFO has a chemical structure of:

wherein the ANFO has a chemical structure of:

and

wherein the DAFO has a chemical structure of:

7. The method as recited in claim 6 , further comprising:

forming the DAFO by reacting 4-amino-1,2,5-oxadiazole-3-carboxamidoxime (AOCA) and 3-amino-4-cyano-1,2,5-oxadiazole (ACOD) with an acid,

wherein the AOCA has a chemical structure of:

and

wherein the COD has a chemical structure of:

8. The method as recited in claim 7 , wherein the acid comprises zinc chloride (ZnCl 2 ).

9. The method as recited in claim 6 , wherein the reacting with oxygen comprises:

mixing the DAFO with a solvent, wherein the solvent is chosen from a group consisting of: trifluoroacetic acid (TFA) and sulfuric acid; and

adding a 50%-90% hydrogen peroxide (H 2 O 2 ) solution to the DAFO and the solvent to form a reaction solution.

10. The method as recited in claim 9 , further comprising cooling the reaction solution to maintain a temperature of less than about 50° C. while stirring the reaction solution for a period of at least 8 hours.

11. The method as recited in claim 6 , further comprising:

extracting the DNFO and the ANFO using an organic solvent;

separating the DNFO using short column chromatography while eluting with a methylene chloride (CH 2 Cl 2 ) and pentane (C 5 H 12 ) solution in about a 2:3 ratio; and

separating the ANFO using short column chromatography while eluting with methylene chloride.

12. The method as recited in claim 9 , wherein the organic solvent comprises at least one of: methylene chloride, toluene (C 6 H 5 CH 3 ), ether (CH 3 —CH 2 —O—CH 2 —CH 3 or R—O—R′, wherein R and R′ are an alkyl group or an aryl group), and ethyl acetate (CH 3 COOCH 2 CH 3 ).

13. The method as recited in claim 9 , further comprising:

purifying the DNFO using at least one of: vacuum sublimation and recrystallization from chloroform (CHCl 3 ); and

purifying the ANFO using recrystallization from ethanol (C 2 H 5 OH).

14. The method as recited in claim 6 , further comprising purifying the DNFO using at least one of: vacuum sublimation and recrystallization.

15. The method as recited in claim 6 , wherein the reacting with oxygen comprises:

suspending the DAFO in an acid, wherein the acid is chosen from a group consisting of: trifluoroacetic acid (TFA) and sulfuric acid; and

adding a 50%-90% hydrogen peroxide (H 2 O 2 ) solution to the DAFO and the acid to form a reaction solution.

16. The method as recited in claim 15 , further comprising cooling the reaction solution to maintain a temperature of less than about 50° C. while stirring the reaction solution for a period of at least 8 hours.

17. The method as recited in claim 15 , further comprising:

adding the reaction solution to water at a temperature of less than about 5° C.;

extracting the DNFO and the ANFO using methylene chloride to provide a product;

washing the product with water;

drying the product over sodium sulfate;

removing solvent from the product using a rotary evaporator; and

separating the DNFO using column chromatography while eluting with methylene chloride.

18. The method as recited in claim 6 , wherein the reacting further comprises adding a zero valence metal to the mixture such that at least one of the DNFO and the ANFO becomes metal-loaded.