176
5 Vibrational Up-Pumping in Polymorphic Materials
A more detailed analysis of the impact-induced polymorphism of γ-FOX-7 can
also be suggested, with the aim of identifying the mechanism for the γ → α transition.
This can be done by monitoring the material during impact by spectroscopic or Xray techniques. Understanding this transformation may be critical to fully rationalise
the transformation that was observed in this work. Additionally, it will be worth
considering the role of the -form (which forms when FOX-7 is exposed to pressure
[21]) in this transformation, and its impact sensitivity relative to the α- and γ-forms.
Furthermore, it is apparent that a deeper correlation between the predicted impact
sensitivity and experimental values must be sought. This can only be obtained by
expanding the set of compounds studied using these models. However, this also
requires accurate capture of the experimental impact sensitivities of EMs, which can
prove difficult in many cases.
References
1. McCrone WC (1965) Polymorphism. In: Fox D, Labes MM, Weissenberg AA (eds) Polymorphism in physics and chemistry of the organic solid state. Interscience, New York, p
726
2. Fabbiani FPA, Pulham CR (2006) High-pressure studies of pharmaceutical compounds and
energetic materials. Chem Soc Rev 35(10):932–942
3. Bernstein J (2002) Polymorphism in molecular crystals. Claredon Press, Oxford
4. Bishop MM, Chellappa RS, Liu Z, Preston DN, Sandstrom MM, Dattelbaum DM, Vohra
YK, Velisavljevic N (2014) High pressure-temperature polymorphism of 1,1-diamino-2,2dinitroethylene. J Phys Conf Ser 500(5):052005
5. Boldyreva EV (2016) Non-ambient conditions in the investigation and manufacturing of drug
forms. Curr Pharm Des 22:1–20
6. Pudipeddi M, Serajuddin ATM (2005) Trends in solubility of polymorphs. J Pharm Sci
94(5):929–939
7. Joiris E, Di Martino P, Berneron C, Guyot-Hermann A-M, Guyot J-C (1998) Compressive
behaviour of orthorhombic paracetamol. Pharm Res 15(7):1122–1130
8. Davidson AJ, Oswald IDH, Francis DJ, Lennie AR, Marshall WG, Millar DIA, Pulham CR,
Warren JE, Cumming AS (2008) Explosives under pressure—the crystal structure of γ-RDX
as determined by high-pressure X-ray and neutron diffraction. CrystEngComm 10(2):162–165
9. Millar DIA, Oswald IDH, Barry C, Francis DJ, Marshall WG, Pulham CR, Cumming AS (2010)
Pressure-cooking of explosives—the crystal structure of ε-RDX as determined by X-ray and
neutron diffraction. Chem Commun 46(31):5662–5664
10. Howard C, Smith L (1961) Studies on the polymorphs of HMX. Los Alamos
11. Soni P, Sarkar C, Tewari R, Sharma TD (2011) HMX polymorphs: gamma to beta phase
transformation. J Energ Mater 29(3):261–279
12. Asay BW, Henson BF, Smilowitz LB, Dickson PM (2003) On the difference in impact
sensitivity of beta and delta HMX. J Energ Mater 21(4):223–235
13. Scott PD (1998) Impact sensitivity testing. Los Alamos
14. Rice BM, Hare JJ (2002) A quantum mechanical investigation of the relation between impact
sensitivity and the charge distribution in energetic molecules. J Phys Chem A 106(9):1770–1783
15. Matyáš R, Pachman J (2013) Primary explosives. Springer, Berlin
16. Herrmann M, Engel W, Eisenreich N (1992) Thermal expansion, transitions, sensitivities and
burning rates of HMX. Propellants Explos Pyrotech 17:190–195
17. Yoo CS, Cynn H (1999) Equation of state, phase transition, decomposition of βHMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine) at high pressures. J Chem Phys
111(22):10229–10235
5 Vibrational Up-Pumping in Polymorphic Materials
A more detailed analysis of the impact-induced polymorphism of γ-FOX-7 can
also be suggested, with the aim of identifying the mechanism for the γ → α transition.
This can be done by monitoring the material during impact by spectroscopic or Xray techniques. Understanding this transformation may be critical to fully rationalise
the transformation that was observed in this work. Additionally, it will be worth
considering the role of the -form (which forms when FOX-7 is exposed to pressure
[21]) in this transformation, and its impact sensitivity relative to the α- and γ-forms.
Furthermore, it is apparent that a deeper correlation between the predicted impact
sensitivity and experimental values must be sought. This can only be obtained by
expanding the set of compounds studied using these models. However, this also
requires accurate capture of the experimental impact sensitivities of EMs, which can
prove difficult in many cases.
References
1. McCrone WC (1965) Polymorphism. In: Fox D, Labes MM, Weissenberg AA (eds) Polymorphism in physics and chemistry of the organic solid state. Interscience, New York, p
726
2. Fabbiani FPA, Pulham CR (2006) High-pressure studies of pharmaceutical compounds and
energetic materials. Chem Soc Rev 35(10):932–942
3. Bernstein J (2002) Polymorphism in molecular crystals. Claredon Press, Oxford
4. Bishop MM, Chellappa RS, Liu Z, Preston DN, Sandstrom MM, Dattelbaum DM, Vohra
YK, Velisavljevic N (2014) High pressure-temperature polymorphism of 1,1-diamino-2,2dinitroethylene. J Phys Conf Ser 500(5):052005
5. Boldyreva EV (2016) Non-ambient conditions in the investigation and manufacturing of drug
forms. Curr Pharm Des 22:1–20
6. Pudipeddi M, Serajuddin ATM (2005) Trends in solubility of polymorphs. J Pharm Sci
94(5):929–939
7. Joiris E, Di Martino P, Berneron C, Guyot-Hermann A-M, Guyot J-C (1998) Compressive
behaviour of orthorhombic paracetamol. Pharm Res 15(7):1122–1130
8. Davidson AJ, Oswald IDH, Francis DJ, Lennie AR, Marshall WG, Millar DIA, Pulham CR,
Warren JE, Cumming AS (2008) Explosives under pressure—the crystal structure of γ-RDX
as determined by high-pressure X-ray and neutron diffraction. CrystEngComm 10(2):162–165
9. Millar DIA, Oswald IDH, Barry C, Francis DJ, Marshall WG, Pulham CR, Cumming AS (2010)
Pressure-cooking of explosives—the crystal structure of ε-RDX as determined by X-ray and
neutron diffraction. Chem Commun 46(31):5662–5664
10. Howard C, Smith L (1961) Studies on the polymorphs of HMX. Los Alamos
11. Soni P, Sarkar C, Tewari R, Sharma TD (2011) HMX polymorphs: gamma to beta phase
transformation. J Energ Mater 29(3):261–279
12. Asay BW, Henson BF, Smilowitz LB, Dickson PM (2003) On the difference in impact
sensitivity of beta and delta HMX. J Energ Mater 21(4):223–235
13. Scott PD (1998) Impact sensitivity testing. Los Alamos
14. Rice BM, Hare JJ (2002) A quantum mechanical investigation of the relation between impact
sensitivity and the charge distribution in energetic molecules. J Phys Chem A 106(9):1770–1783
15. Matyáš R, Pachman J (2013) Primary explosives. Springer, Berlin
16. Herrmann M, Engel W, Eisenreich N (1992) Thermal expansion, transitions, sensitivities and
burning rates of HMX. Propellants Explos Pyrotech 17:190–195
17. Yoo CS, Cynn H (1999) Equation of state, phase transition, decomposition of βHMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine) at high pressures. J Chem Phys
111(22):10229–10235