Molecular structure of 2,4,6-trinitrotoluene

Carper, W. Robert; Davis, Larry P.; Extine, M. W.

doi:10.1021/j100393a009

Cited by 102 publications

(50 citation statements)

References 4 publications

(6 reference statements)

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“…2). 26 We have previously shown 27 that this yields well converged results compared to experiment. Diamond is modeled using a C 47 H 60 hydrogen-capped cluster, shown in Fig.…”

Section: Computational Details a Model Systemsmentioning

confidence: 71%

Local time-correlation approach for calculations of x-ray spectra

2012

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We present a local time-correlation function method for real-time calculations of core level x-ray spectra (RTXS). The approach is implemented in a local orbital basis using a Crank-Nicolson timeevolution algorithm applied to an extension of the SIESTA code, together with projector augmented wave (PAW) atomic transition matrix elements. Our RTXS is formally equivalent to ∆SCF Fermi's golden rule calculations with a screened core-hole and an effective independent particle approximation. Illustrative calculations are presented for several molecular and condensed matter systems and found to be in good agreement with experiment. The method can also be advantageous compared to conventional frequency-space methods.

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“…2). 26 We have previously shown 27 that this yields well converged results compared to experiment. Diamond is modeled using a C 47 H 60 hydrogen-capped cluster, shown in Fig.…”

Section: Computational Details a Model Systemsmentioning

confidence: 71%

Local time-correlation approach for calculations of x-ray spectra

2012

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“…The common monoclinic [6,7] and orthorhombic [8] forms both have a crystallographic repeat unit which consists of two molecules, so both groups of ν + and ν − 14 N NQR transitions consist of six lines. The monoclinic TNT is the stable polymorph up to its melting point at 81°C although the metastable orthorhombic form can survive for long periods at ambient temperatures, but it converts to monoclinic near 70°C with a low enthalpy of transformation [7] and can convert slowly at intermediate temperatures.…”

Section: Experimental Methodsmentioning

confidence: 99%

“…For example they are estimated to be larger than 31 kJ mol -1 in m-chloronitrobenzene [17] [31] have been measured. These values seem to bear little relationship to the C-N bond length; its average values in the two molecules in the monoclinic form of TNT are 147.5 pm [6] and 148.2 pm [8], in the orthorhombic form the average of the two is 147 pm and in gaseous nitrobenzene 146.8 pm [31]. Our values of E a (T 1 ) in Table 3 suggest there is little difference between the ortho and para NO 2 groups in monoclinic TNT since for both the activation energies are close to 90 kJ mol -1 but for orthorhombic TNT, at least for the para group, E a (T 1 ) is somewhat lower at 70 kJ mol -1 .…”

Section: The 14 N Nqr Relaxation Times and Signal Decay Times Of Tntmentioning

confidence: 99%

14N NQR, relaxation and molecular dynamics of the explosive TNT

Smith

Rowe

Althoefer

et al. 2015

Solid State Nuclear Magnetic Resonance

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Multiple pulse sequences are widely used for signal enhancement in NQR detection applications. Since the various 14 N NQR relaxation times, signal decay times and frequency of each NQR line have a major influence on detection sequence performance, it is important to characterise these parameters and their temperature variation, as fully as possible. In this paper we discuss such measurements for a number of the ν + and ν − NQR lines of monoclinic and orthorhombic TNT and relate the temperature variation results to molecular dynamics. The temperature variation of the 14 N spin-lattice relaxation times T 1 is interpreted as due to hindered rotation of the NO 2 group about the C-NO 2 bond with an activation energy of 89 kJ mol -1 for the ortho and para groups of monoclinic TNT and 70 kJ mol -1 for the para group of orthorhombic TNT.

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“…An X-ray diffraction study of TNT (5) again revealed the presence of two structures, denoted A and B. 16 The nitro groups were all rotated out of the ring plane, 4-nitro groups by 24˚ and 30˚, respectively, and 2-and 6-nitro groups by 43˚ -60˚. Both intramolecular H-bonding and repulsion of HMPA are expected to diminish or disappear, hence the sizable non-zero values of K eq /H for (5), (6), and (7).…”

Section: 35-trinitrobenzene and Steric Effectsmentioning

confidence: 98%

Formation constants in C–H hydrogen bonding. 4. Effects of cyano, nitro, and trifluoromethyl substituents in aromatic compounds

Lorand¹

2014

Arkivoc

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Formation constants (K eq ) have been measured using 1 H NMR for H-bond complexes with HMPA in CCl 4 of 35 aromatic compounds variously substituted with cyano, nitro, and trifluoromethyl groups; several compounds contained F and Cl. The three strongly polar groups enhance H-bonding significantly, usually in the order NO 2 > CN > CF 3 ; all are superior to Cl and F. 1,3,5-Trinitrobenzene fails to H-bond at all; however, TNT, its tert-butyl analog, and trinitro-m-xylene show significant K eq values. Coplanarity of nitro groups with the ring blocks approach of HMPA, probably via intramolecular H-bonds. The buttressing effect is evident in some crowded compounds.

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Molecular structure of 2,4,6-trinitrotoluene

Cited by 102 publications

References 4 publications

Local time-correlation approach for calculations of x-ray spectra

Local time-correlation approach for calculations of x-ray spectra

14N NQR, relaxation and molecular dynamics of the explosive TNT

Formation constants in C–H hydrogen bonding. 4. Effects of cyano, nitro, and trifluoromethyl substituents in aromatic compounds

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