Chiral explosives: A theoretical investigation of structure and chiroptical properties of triacetone triperoxide and hexamethylene triperoxide diamine. Issue 4 (18th January 2023)

• Record Type: Journal Article
• Authors: Puente, Andrew R.; Polavarapu, Prasad L.
• Is Part Of: Chirality. Volume 35:Issue 4(2023)
• Page Start: 211
• Page End: 226
• Publication Date: 2023-01-18
• Subjects: explosives -- hexamethylene triperoxide diamine -- optical rotatory dispersion -- Raman optical activity -- transition states -- triacetone triperoxide -- vibrational circular dichroism; Chirality -- Periodicals; Pharmaceutical chemistry -- Periodicals; 541.22
• DOI: 10.1002/chir.23532
• Languages: English
• ISSNs: 0899-0042

Abstract

Abstract: Triacetone triperoxide (TATP) and hexamethylene triperoxide diamine (HMTD) are cyclic peroxides that exhibit atropisomerism resulting from restricted rotation around three peroxide bonds. As a result, one pair of enantiomers with D3 symmetry and another pair of enantiomers with C2 symmetry can be identified. Previous studies, based on mass spectrometry data and computational results, have shown that conformations of TATP with D3 and C2 symmetry can be isolated. Assuming that enantiomer samples of TATP and HMTD can be obtained with sufficient enantiopurity, we investigated their chiroptical properties, namely, optical rotatory dispersion (ORD), vibrational circular dichroism (VCD), and Raman optical activity (VROA). ORD curves and VCD spectra are seen to be very similar for D3 ‐ and C2 ‐symmetric atropisomers with the same overall helicity. Predicted VROA results, however, show significant differences between D3 ‐ and C2 ‐symmetric atropisomers with the same overall helicity. The D3 ‐symmetric atropisomer is predicted to exhibit considerably larger magnitude vibrational optical activity signals than the C2 ‐symmetric atropisomer. Abstract : The transition states and energy barrier for racemization of D3 ‐symmetric and C2 ‐symmetric atropisomers of TATP and HMTD are determined. The magnitudes of predicted VOA spectral intensities for D3 symmetric atropisomer are greater than those for C2 symmetric atropisomer of same overall helicity. The ROA spectra are predicted to have sufficient differences for identifying of D3 ‐ and C2 ‐symmetric atropisomers of the same overall helicity.