Laser ionization of solid RDX: a density functional theory study

Akin, F. Ahu; Kıyak, Güven

doi:10.1007/s11224-018-1191-4

Cited by 6 publications

(3 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The crystal lattice of HHTT essentially contains four pairs of inverted interlocked HHTT molecules (labeled as I–II, I′–II′, I″–II″, and I‴–II‴ pairs, respectively, in Figure A) . Such an interlocked pairwise structure has been known to be important, and has been used in recent years to computationally model the crystal structure of HHTT, and to model laser ionized solid HHTT material . Thus, a representative dimer of such is taken from the HHTT unit cell in our work, which is molecule-I and molecule-II in Figure A, and is hence named “I–II dimer”.…”

Section: Resultsmentioning

confidence: 99%

“…26 Such an interlocked pairwise structure has been known to be important, and has been used in recent years to computationally model the crystal structure of HHTT, 46 and to model laser ionized solid HHTT material. 47 Thus, a representative dimer of such is taken from the HHTT unit cell in our work, which is molecule-I and molecule-II in Figure 4A, and is hence named "I−II dimer". Such an HHTT dimer is separately shown in Figure 4B, after further structural optimization, where the distances between HHTT molecule-II's O 33 and molecule-I's O 11 is 3.51 Å, and that of molecule-II's O 36 and molecule-I's H 20 is 2.47 Å.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Ultrafast Intermolecular Vibrational Energy Transfer in Hexahydro-1,3,5-trinitro-1,3,5-triazine in Molecular Crystal by 2D IR Spectroscopy

Shi

Zhao

et al. 2020

J. Phys. Chem. C

View full text Add to dashboard Cite

Cyclic nitramine hexahydro-1,3,5-trinitro-s-triazine (HHTT) is an important energetic molecule with a variety of applications. In this work, structural dynamics and vibrational-energy transfer dynamics of HHTT were investigated using steady-state infrared (IR), femtosecond time-resolved IR, and two-dimensional (2D) IR spectroscopic methods. Two different structural forms of HHTT (isolated molecules dissolved in DMSO and microcrystal dispersed in paraffin oil) were examined using the NO2 asymmetric stretching mode as a structural marker. Both intra- and intermolecular vibrational energy transfers were observed in HHTT microcrystal, where the well-known α-conformation was retained. However, less perfect α-HHTT species was found in DMSO. An intermolecular energy dissipation pathway was found to be related to Davydov splitting in the microcrystal form of HHTT, which originates from intermolecular interactions (e.g., electrostatic and hydrogen bonds). Experimental results were supported by quantum-chemistry computations. In addition, both vibrational excited-state relaxation and vibrational energy-transfer processes were found to be more efficient in HHTT microcrystal than in the solvated form. Our work provides a chemical-bond level of insight into the nitro group-containing energetic materials.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Ultrafast Intermolecular Vibrational Energy Transfer in Hexahydro-1,3,5-trinitro-1,3,5-triazine in Molecular Crystal by 2D IR Spectroscopy

Shi

Zhao

et al. 2020

J. Phys. Chem. C

View full text Add to dashboard Cite

show abstract

“…Our previous density functional theory (DFT) study of a dimeric RDX lattice cell model showed that loss of an electron could result in HONO and NO2 losses via unimolecular or bimolecular processes. 38 A DFT study on band-gap calculations of -RDX crystal has produced a band-gap of 3.0-3.1 eV at zero external pressure, less than the calculated vertical ionization energy of a single RDX molecule (10.4-10.9 eV) 39 . Molecular dynamics simulations show that amorphous Al2O3 (a-Al2O3) have smaller band gaps than the crystalline phase.…”

Section: Introductionmentioning

confidence: 95%

Hydrogen Bonding, Electron Transfer and Orbital Interactions between RDX and Al3O3-: Forces governing the initial encounter

AKIN

2023

Preprint

View full text Add to dashboard Cite

As the first step in energy transfer from oxide passivated metal nanoparticles/surface defects to an energetic molecule for the controlled dissociation of the latter, the nature of the weak interactions between RDX and Al3O3- isomers are studied as a model system by DFT method with PBE0 functional and different basis sets (TZVP, Def2-TZVPP, TZ2P). Different electron density (NCI, IGMH, QTAIM, IQA, EDA-NOCV) and charge analysis methods (Hirshfeld, Mulliken, Hirshfeld-I, NPA) reveal that partial charge-transfer from Al3O3- to RDX via the C-H···O (1.851-2.481Å, O(2p)-to-C-H(*) type) and the C-H···Al (2.836-2.871Å, Al(3p)-to-C-H(*) type) interactions are possible. Hirshfeld analysis predicts 6-25% transfer of the -1 charge to RDX while Hirshfeld-I, NPA, and Mulliken predict 7-22%, 2-7%, and 7-13% transfer, respectively. Al3O3- (HOMO)-RDX (LUMO+n, n=0-3) type interactions including the charge transfer via the (ON)O···Al (2.846-3.511Å) interactions are found to excite the Al3O3 (kite) anion. The binding energies are in the -10 to -31 kcal/mol range. Vertical detachment energies of the complexes are within 2.5-3.9 eV, higher than the bare Al3O3- isomers by 0.3-1.3 eV. Complexation weakens the RDX structure and reduces the C-H stretching frequencies by 10-350 cm-1. Modulations in the bond lengths in the Al3O3 isomers shift the frequencies in the 0-1300 cm-1 region. New intermolecular vibrations enrich the terahertz region of the IR spectra. Complexation is found to augment the resultant dipole moment from 2.7 (Al3O3- (rec)) and 8.6 (Al3O3- (kite)) to the 2.9-16.0 Debye range, signalling effects on the workfunction of the aluminum oxide surfaces upon binding.

show abstract

Interplay of thermochemistry and Structural Chemistry, the journal (volume 30, 2019, issues 1–2) and the discipline

2020

View full text Add to dashboard Cite

Laser ionization of solid RDX: a density functional theory study

Cited by 6 publications

References 43 publications

Ultrafast Intermolecular Vibrational Energy Transfer in Hexahydro-1,3,5-trinitro-1,3,5-triazine in Molecular Crystal by 2D IR Spectroscopy

Ultrafast Intermolecular Vibrational Energy Transfer in Hexahydro-1,3,5-trinitro-1,3,5-triazine in Molecular Crystal by 2D IR Spectroscopy

Hydrogen Bonding, Electron Transfer and Orbital Interactions between RDX and Al3O3-: Forces governing the initial encounter

Interplay of thermochemistry and Structural Chemistry, the journal (volume 30, 2019, issues 1–2) and the discipline

Contact Info

Product

Resources

About