| Polyazide Chemistry. Preparation and Characterization of the First Binary Group 6 Azides, Mo(N3)6, W(N3)6, Mo(N3)7- and W(N3)7- and the NW(N3)4- and NMo(N3)4- Ions |
NOV 2004 |
6 pages |
| Authors:
Ralf Haiges; Jerry A. Boatz; Robert Bau; Stefan Schneider; Thorsten Schroer; Muhammed Yousufuddin; Karl O. Christe; AIR FORCE RESEARCH LAB EDWARDS AFB CA SPACE AND MISSILE PROPULSION DIV
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 | Whereas numerous binary transition-metal azido complexes have been reported,1 no binary Group 6 azides are known. Only a limited number of partially azide-substituted molybdenum and tungsten compounds have been reported. Furthermore, no heptaazido compounds have been described. Herein, we report the synthesis and characterization of the first binary Group 6 azides, Mo(N3)6, W(N3)6, Mo(N3)7-, and W(N3)7-. The last two ions represent the first examples of heptaazides. We also report the ... |
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| Polyazide Chemistry Preparation and Characterization of As(N3)5, Sb(N3)5 and P(C6H5)4Sb(N3)6 |
SEP 2004 |
19 pages |
| Authors:
Ralf Haiges; Jerry A. Boatz; Ashwani Vij; Vandana Vij; Michael Gerken; Stefan Schneider; Thorsten Schroer; Muhammed Yousufuddin; Karl O. Christe; AIR FORCE RESEARCH LAB EDWARDS AFB CA SPACE AND MISSILE PROPULSION DIV
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| The binary arsenic- and antimony azide species AS(N3)3, As(N3)4+, As(N3)4-, As(N3)6-, Sb(N3)3, Sb(N3)4+, Sb(N3)4- and Sb(N3)6- have previously been reported, and the crystal structures of As(N3)3, Sb(N3)3 and As(N3)6- were determined. In addition, the Lewis based stabilized species M(N3)5-LB (M=As,Sb; LB=pyridine, quinoline NH3, N2H4, NH2CN) were published. However, previous attempts to obtain the neat pentaazides of arsenic and antimony were not successful. Even at low temperatures, attempted syntheses resulted in ... |
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| Fluoride/Azide Ligand Exchange Reactions |
12 JUL 2004 |
22 pages |
| Authors:
Ralf Haiges; Stefan Schneider; Thorsten Schroer; Michael Gerken; Jerry Boatz; ENGINEERING RESEARCH AND CONSULTING INC(ERC INC) EDWARDS AFB CA
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| This document contains Briefing charts only which were presented at European Symposium on Fluorine Chemistry, Poznan, Poland. |
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| The NH3Cl+ Cation |
21 MAY 2004 |
20 pages |
| Authors:
Stefan Schneider; Ralf Haiges; Thorsten Schroer; Jerry Boatz; Karl O. Christe; AIR FORCE RESEARCH LAB EDWARDS AFB CA SPACE AND MISSILE PROPULSION DIV
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| Whereas at least seven simple inorganic cations, NH3F+,1,2 NH2F2+,3 NF4+,4 N2F+,5 N2F3+,6 ONF2+,7 and N3NOF+,8 which contain N-F bonds, have been prepared and well characterized, the existence of corresponding N-Cl containing cations is not well established. Thus, only two N-Cl containing cations, NCl4+9 and ONCl2+,10,11 have been reported, however, our repeated attempts to duplicate their syntheses were unsuccessful, and the crystal structure, published for ONCl2+SbCl6-,10 has been challenged on theoretical ... |
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| High Energy Density Materials |
23 MAR 2004 |
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| Authors:
Ralf Haiges; Stefan Schneider; Thorsten Schroer; Karl O. Christe; ENGINEERING RESEARCH AND CONSULTING INCHUNTSVILLE AL
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 | During the past two decades, polynitrogen compounds have received increasing attention as promising candidates for High Energy Density Materials (HEDM).1-17 While most of the efforts were devoted to theoretical studies, the long-known existence of the stable azide anion (N3-)18 and the recent syntheses of stable salts of the pentanitrogen cation (N5+)1-3 have demonstrated the feasibility of experimentally pursuing such materials. The only known direct method for preparing N5+ compounds is ... |
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| Preparation and Characterization of the First Binary Titanium Azides, Ti(N3)4, P(C6H5)4Ti(N3)5 and P(C6H5)42Ti(N3)6 and on Linear Ti-N-NN Coordination |
12 MAR 2004 |
21 pages |
| Authors:
Karl O. Christe; Ralf Haiges; Stefan Schneider; Thorsten Schroer; Jerry A. Boatz; ENGINEERING RESEARCH AND CONSULTING INCHUNTSVILLE AL
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| Where as numerous partially azide-substituted titanium compounds had previously been reported, 1-7 no binary titanium azides were known. In a recent theoretical study the group 4 metal tetrazides M(N3)4 (M = Ti, Zr, Hf, Th) were predicted 8 to be vibrationally stable exhibiting tetrahedral structures with unique linear M-N-NN bond angles (see Figure 1). All previously characterized covalent binary azide species possess bent M-N-NN angles. In this paper we wish ... |
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| Towards New Polynitrogen Species: The Search for Viable Precursors |
31 MAR 2003 |
22 pages |
| Authors:
Jerry A. Boatz; Karl Christie; Ralph Haiges; Stefan Schneider; Thorsten Schroer; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE
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| Towards New Polynitrogen Species: The Search for Viable Precursors |
29 JAN 2003 |
28 pages |
| Authors:
Karl Christe; Ralf Haiges; Stefan Schneider; Thorsten Schroer; Ashwani Vij; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE WEST
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| The presentation slides for the briefing concerning, Towards New Polynitrogen Species: The Search for Viable Precursors are presented. |
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| Polyazide Chemistry Preparation and Characterization of Te(N3)4 and P(C6H5)42Te(N3)6 |
2003 |
23 pages |
| Authors:
Ralf Haiges; Jerry A. Boatz; Michael Gerken; Stefan Schneider; Thorsten Schroer; ENGINEERING RESEARCH AND CONSULTING INC(ERC INC) EDWARDS AFB CA
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| The azido-group is highly energetic and adds about 70 kcal/mol to the energy content of a molecule. It is, therefore, not surprising that polyazides are highly endothermic compounds, and that their energy content increases with an increasing number 9f azido ligands. Compared to the relatively stable azide anion, which possesses two double bonds, the bonds in covalent azides are polarized towards a single and a triple bond, which greatly facilitates ... |
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| First Structural Characterization of Binary As(III) and Sb(III) Azides |
2003 |
39 pages |
| Authors:
Ralf Haige; Ashwani Vij; Jerry Boatz; Stefan Schneider; Thorsten Schroer; ENGINEERING RESEARCH AND CONSULTING INC(ERC INC) EDWARDS AFB CA
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| The highly explosive molecules As (N3)3 and Sb(N3)3 were obtained for the first time in pure form by the reactions of the corresponding fluorides with (CH3)3SiN3 in SO2 solution and purification by sublimation. The crystal structures, 14N NMR and infrared and Raman spectra were determined and the results compared to ab initio second order perturbation theory calculations. Whereas Sb(N3)3 possesses a propeller-shaped, pyramidal structure with perfect C3 symmetry, the As(N3)3 ... |
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| Tritylsulfinylamine: A New Member in the Family of Sulfinylamines |
25 SEP 2002 |
23 pages |
| Authors:
Karl O. Christe; Michael Gerken; Ralf Haiges; Stefan Schneider; Thorsten Schroer; UNIVERSITY OF SOUTHERN CALIFORNIA LOS ANGELES DEPT OF CHEMISTRY
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| Triphenylmethyl N-sulfinylamine (trityl-NSO) was prepared from the reaction of trityl amine and SOCl2. Trityl-NSO was characterized by 1H, 13C, and 14N NMR spectroscopy in CH2C12 solution and by Raman and infrared spectroscopy in the solid state. Crystals of trityl NSO were grown from n-heptane and characterized by single crystal X-ray diffraction (P1-bar, alpha = 8.9642(9) A, b = 9.2135(9) A, c = 11.0645(11) A, alpha = 93.578(2)0, Beta = 101.098(2)0, ... |
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| The (SO2)2N3 Anion |
AUG 2002 |
18 pages |
| Authors:
Karl O. Christie; Michael Gerken; Ralf Haiges; Stefan Schneider; Thorsten Schroer; ENGINEERING RESEARCH AND CONSULTING INCEDWARDS AFB CA
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| The recently proposed (S02)2N3(-) anion was structurally characterized by single crystal X-ray diffraction of the Cs(S02)2N3 salt (P21/c, a = 8.945(2) A, b = 10.454(2) A, c = 8.152(2) A, a(^) = 109.166(3)(sup o), Z = 4, and R1 = 0.0329 at 130 K). In the (SO2)2N3(-) anion, both SO2 ligands are coordinated to one terminal nitrogen atom of the N3-(-) anion. |
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| Triphenylmethyldifluoramine: A Stable Reagent for the Synthesis of gem- Bis(difluoramines) |
29 APR 2002 |
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| Authors:
G. K. Prakash; Markus Etzkorn; George A. Olah; Karl O. Christe; Stefan Schneider; UNIVERSITY OF SOUTHERN CALIFORNIA LOS ANGELES LOKER HYDROCARBON RESEARCH INST
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| The conversion of ketones into geminal bis(difluoramines) can be achieved under mild two phase reaction conditions by employing triphenylmethyldifluoramine as an in situ source of difluoramine. |
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| Synthesis and Characterization of the SO2N3(-), (SO2)2N3(-), and SO3N3(- ) Anions |
06 MAR 2002 |
51 pages |
| Authors:
Karl O. Christe; Jerry A. Boatz; Michael Gerken; Ralf Haiges; Stefan Schneider; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE WEST
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| SO2 solutions of azide anions are bright yellow and their Raman spectra indicate the presence of covalently bound azide. Removal of the solvent at -64 deg C from CsN3 or N(CH3)4N3 solutions produces yellow (SO2)2N3(-) salts. Above -64 deg C, these salts lose one mole of SO2, resulting in white SO2N3 salts that are marginally stable at room temperature and thermally decompose to the corresponding azides and SO2. |
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| Improved Synthesis of CsN3 |
17 DEC 2001 |
7 pages |
| Authors:
Michael Gerken; Stefan Schneider; Thorsten Schroer; Karl O. Christe; UNIVERSITY OF SOUTHERN CALIFORNIA LOS ANGELES LOKER HYDROCARBON RESEARCH INST
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| Cesium azide can conveniently be prepared from anhydrous CsF and (CH3)3SiN3 in SO2 solvent in high purity and yield. In this reaction, the initially generated SO2F(-) anion is converted in SO2 solvent to solvated azide, (SO2)(sub n)N3(-), which is labile and releases S02 under dynamic vacuum yielding pure CsN3. |
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| In Pursuit of the PO2+ Cation. The Reaction of KPO2F2 and SbF5 Leads to an Eight-Membered, Antimony-Oxygen-Phosphorus-Bridged Ring |
08 DEC 2000 |
29 pages |
| Authors:
Stefan Schneider; Ashwani Vij; Jeffrey A. Sheehy; Thorsten Schroer; Karl O. Christe; AIR FORCE RESEARCH LAB EDWARDS AFB CA SPACE AND MISSILE PROPULSION DIV
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| The reaction of KPO2F2 with the strong Lewis acid SbF3 was studied as a potential pathway to the unknown PO2(+) cation. The resulting product has the desired PO2SbF6 composition but consists of an eight-membered, oxygen-bridged ring that was characterized by vibrational and NMR spectroscopy, ab initio methods, and a single crystal x-ray diffraction study. The formation of the oxygen-bridged ring and its mechanism are discussed. |
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