O:H–N bond cooperativity in the energetic TATB under mechanical and thermal perturbation

Incorporating the mechanical and thermal perturbations to the Raman spectroscopy has enabled resolution to the response of the individually segmented C–N[dbnd]2H:2O[dbnd]N–C interactions for the 1,3,5-triamona, 2,4,6-trinitorbenzene (TATB, C₆H₆N₆O₆) assembly with “:” representing the electron lone pair of nitrogen or oxygen at the molecular interfaces. It is uncovered that: (i) the N–H bond possesses the negative compressibility and negative thermal expansivity; (ii) the C–(N[dbnd]2H) bond undergoes both compressive and thermal contraction; (iii) the (O,N):H and rest interactions follow the regular compressibility and thermal expansivity. The unusual response of the H–N bond in TATB to perturbation is the same to the H–O segment of the O:H–O bond of water ice and the N:H–O bond of the cyclo-N₅⁻:4H₃O⁺ complexes, which proves that the O:⇔:N repulsion couples the inter-(O:H) and the intramolecular (H–N) interactions and drives the O:H–N to relax cooperatively in the segmental length, energy, and vibration frequency when subjecting to perturbation. Discoveries demonstrate not only the significance of molecular coupling interactions but also the power of mechanical and thermal perturbations that enable detailed information of individual bond relaxation, advancing the engineering in chemistry and devising of functional molecular materials.