NQR/NMR Studies of Solid Phase Energetic Materials

1990 ◽  
pp. 715-738 ◽  
Author(s):  
R. A. Marino
Keyword(s):  
Energetic Materials ◽  
Solid Phase ◽  
Nmr Studies

Bis-phosphonio-isophosphindolide Copper Complexes

1999 ◽  
Vol 54 (10) ◽  
pp. 1244-1252 ◽  
Author(s):  
Dietrich Gudat ◽  
Andreas W. Holderberg ◽  
Nikolaus Korber ◽  
Martin Nieger ◽  
Martin Schrott
Keyword(s):  
Copper Complexes ◽  
Dynamic Equilibrium ◽  
Solid Phase ◽  
Lone Pair ◽  
Binuclear Complexes ◽  
Exchange Reactions ◽  
Nmr Studies ◽  
Bonding Parameters ◽  
Stability Of Complexes ◽  
The Stability

Bis-triphenylphosphonio-isophosphindolide salts 1[X] react with Cu(I)-halides CuX to give isolable products of composition [(1)Cu2X3 ]. X-ray crystal structure analyses confirmed that for X = Br, Cl dinuclear complexes [(μ-1 )(μ-X)Cu2X2] with μ2, η1(P)-bridging cations 1 are formed, while for X = I a solid phase containing a salt (1)2[Cu4I6] and a complex [(1)2Cu4I6] with a terminal η1(P)-coordinated ligand 1 was obtained. The bonding parameters in the two types of complexes suggest that l i s a hybrid between a phosphenium cation and a phospholide anion whose π-system is less nucleophilic than the phosphorus lone-pair.31P NMR studies revealed that in solution in all cases binuclear complexes [(1)Cu2X3] are in dynamic equilibrium with small amounts of mononuclear species and free 1. The same equilibria were detected in the system 1[OTf]/CuOTf. NMR studies of ligand exchange reactions indicated that the stability of complexes [(1)Cu2X3 ] increases in the order X = OTf < I < Br, Cl, and titration of [(1)Cu2Br3] with Et4NBr allowed to determine the equilibrium constant of the complex formation reaction.

scholarly journals An Energetic Model for Detonation of Granulated Solid Propellants

Energies ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4459 ◽  
Author(s):  
López-Munoz ◽  
García-Cascales ◽  
Velasco ◽  
Otón-Martínez
Keyword(s):  
Energetic Materials ◽  
Solid Phase ◽  
Constitutive Relations ◽  
Particle Interaction ◽  
Combustion Process ◽  
Numerical Schemes ◽  
Mass Generation ◽  
Interphase Heat Transfer ◽  
Early Stages ◽  
Granular Solid

Unexpected detonation of granular solid energetic materials is a key safety issue in the propellants manufacturing industry. In this work, a model developed for the characterization of the early stages of the detonation process of granular solid energetic materials is presented. The model relies on a two-phase approach which considers the conservation equations of mass, momentum, and energy and constitutive relations for mass generation, gas-solid particle interaction, interphase heat transfer, and particle-particle stress. The work considers an extension of approximated Riemann solvers and Total Variation Diminishing (TVD) schemes to the solid phase for the numerical integration of the problem. The results obtained with this model show a good agreement with data available in the literature and confirm the potential of the numerical schemes applied to this type of model. The results also permit to assess the effectiveness of different numerical schemes to predict the early stages of this transient combustion process.

FT-IR Standoff Detection of Thermally Excited Emissions of Trinitrotoluene (TNT) Deposited on Aluminum Substrates

2013 ◽  
Vol 67 (2) ◽  
pp. 181-186 ◽  
Author(s):  
John R. Castro-Suarez ◽  
Leonardo C. Pacheco-Londoño ◽  
Miguel Vélez-Reyes ◽  
Max Diem ◽  
Thomas J. Tague ◽  
...  
Keyword(s):  
Energetic Materials ◽  
Solid Phase ◽  
Detection System ◽  
Target Surface ◽  
Least Squares Regression ◽  
Passive Mode ◽  
Standoff Detection ◽  
Highly Energetic Materials ◽  
Aluminum Plates ◽  
Aluminum Substrates

A standoff detection system was assembled by coupling a reflecting telescope to a Fourier transform infrared spectrometer equipped with a cryo-cooled mercury cadmium telluride detector and used for detection of solid-phase samples deposited on substrates. Samples of highly energetic materials were deposited on aluminum substrates and detected at several collector-target distances by performing passive-mode, remote, infrared detection measurements on the heated analytes. Aluminum plates were used as support material, and 2,4,6-Trinitrotoluene (TNT) was used as the target. For standoff detection experiments, the samples were placed at different distances (4 to 55 m). Several target surface temperatures were investigated. Partial least squares regression analysis was applied to the analysis of the intensities of the spectra obtained. Overall, standoff detection in passive mode was useful for quantifying TNT deposited on the aluminum plates with high confidence up to target–collector distances of 55 m.

Dibenzo-15-crown-5 ether and its sodium thiocyanate complex. X-ray crystallographic and NMR studies in the solid phase and in solution

1991 ◽  
Vol 69 (3) ◽  
pp. 404-414 ◽  
Author(s):  
G. W. Buchanan ◽  
S. Mathias ◽  
Y. Lear ◽  
C. Bensimon
Keyword(s):  
Solid Phase ◽  
Free Ligand ◽  
Resonance Assignments ◽  
Sodium Thiocyanate ◽  
Torsional Angle ◽  
Nmr Studies ◽  
Thiocyanate Complex ◽  
X Ray ◽  
Asymmetric Structures ◽  
Temperature Solution

For the title systems, single crystal X-ray data indicate the presence of totally asymmetric structures. These features are reflected in the multiplicity of resonances in the solid phase 13C NMR spectra. Some of the 13C chemical shift trends are analyzed in terms of torsional angle influences. In solution, resonance assignments have been made with the aid of 2D methods. Stereochemical inferences are drawn from NOESY spectra and 1H–1H couplings. Low temperature solution experiments indicate that conformational interconversions in both the free ligand and the NaNCS complex are rapid on the NMR timescale down to 163 K. Key words: crown ethers, NMR, stereochemistry.

An example of conformational disorder in solids: X-ray crystallographic and 13C CPMAS NMR studies of dibenzo and dicyclohexano-13-crown-4 ethers and some lithium complexes

1990 ◽  
Vol 68 (1) ◽  
pp. 49-58 ◽  
Author(s):  
G. W. Buchanan ◽  
R. A. Kirby ◽  
J. P. Charland
Keyword(s):  
Crystal Structure ◽  
Crown Ethers ◽  
Nmr Spectra ◽  
Solid Phase ◽  
Nmr Studies ◽  
13C Cpmas Nmr ◽  
Conformational Disorder ◽  
X Ray ◽  
Lithium Complexes ◽  
Cis Isomer

For the cis–anti–cis isomer of dicyclohexano-13-crown-4 ether, disorder has been detected in the crystal structure, with two conformations being present in the ratio of ca. 3:2. Crystal structures for two Li+ complexes of the cis–syn–cis isomer have also been determined. Representative 13C solid phase NMR spectra are presented and discussed for these systems and the related dibenzo substituted compounds. Keywords: crown ethers, solids, NMR, conformation.

Benzo-9-crown-3 ether: X-ray crystal structure, NMR studies in solution and the solid phase, and ab initio calculations of isotropic 13C chemical shifts using LORG with a D95V basis set

1993 ◽  
Vol 71 (12) ◽  
pp. 1983-1989 ◽  
Author(s):  
G.W. Buchanan ◽  
A.B. Driega ◽  
A. Moghimi ◽  
C. Bensimon ◽  
R.A. Kirby ◽  
...  
Keyword(s):  
Ab Initio ◽  
Solid Phase ◽  
Chemical Shifts ◽  
Basis Set ◽  
Length Variation ◽  
Nmr Studies ◽  
Nmr Spectrum ◽  
X Ray ◽  
Localized Orbital ◽  
C Nmr

Using the X-ray crystal geometry as input, the 13C NMR chemical shifts of benzo-9-crown-3 ether have been calculated via ab initio methods using a localized orbital local origin (LORG) approach. Reasonable agreement is found between the calculated values for an isolated molecule in the gas phase and those obtained in the 13C CPMAS NMR spectrum. Solid phase 13C spectra of the C7,10-d4 derivative confirm the existence of a 7.9 ppm shift difference between these sites in the solid, whereas in solution they are conformationally averaged to one resonance. The effects of C—H bond length variation on calculated 13C shifts have been explored.

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