| History of the AFRL/USC DARPA Program on Polynitrogen Chemistry. Volume 2 |
OCT 2004 |
143 pages |
| Authors:
Karl O. Christe; Ashwani Vij; ENGINEERING RESEARCH AND CONSULTING INC(ERC INC) EDWARDS AFB CA
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 | In the course of the High Energy Density Matter (HEDM) Program, which was initiated in 1986 by the Air Force, the potential of polynitrogen compounds for HEDM was recognized by numerous theoretical studies. However, no systematic efforts were undertaken to synthesize any of the potential candidates predicted by the theoreticians. This changed in 1998, when Dr. Oestmark from the Swedish Defense Research Agency proposed to DARPA an experimental study to ... |
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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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| European Symposium on Fluporine Chemistry, Pizbab (Poland) (14th). Self Assembly of ULtrahydrophobic |
15 JUL 2004 |
53 pages |
| Authors:
Ashwani Vij; Joseph Mabry; AIR FORCE RESEARCH LAB EDWARDS AFB CA SPACE AND MISSILE PROPULSION DIV
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| Solid State Structural Studies of Some New Derivatives of HN(SO2CF3)2 and HOTeF5 |
07 JUN 2004 |
41 pages |
| Authors:
Vandana Viji; Ashwani Vij; Jerry Boatz; ENGINEERING RESEARCH AND CONSULTING INCHUNTSVILLE AL
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| The cisoid form is less common. In the CCDC, only 6 structures show this conformation whereas the transiod form occurs in 15 remaining structures The cisoid conformation results from stronger cation-anion interaction Cisoid observed exclusively when anion is chelated to the metal center The transoid form dominates in structures containing a free anion NO structure known containing both cisoid AND transoid geometry |
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| Polynitrogen and High Nitrogen Chemistry: A New World of Challenges |
25 MAR 2004 |
85 pages |
| Authors:
Ashwani Vij; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE
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| Polynitrogen compounds contain only nitrogen atoms and are expected to have unusual properties. Most important among these are: High endothermicity Green propellant combustion product is only gaseous N2 High density High Isp values when compared to other monopropropellants or bipropellants High detonation velocity |
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| Polynitrogen Chemistry: Recent Development in Pentazole and Polyazide Chemistry |
24 MAR 2004 |
18 pages |
| Authors:
Ashwani Vij; Vandan Vij; R. Haiges; Karl O. Christe; ENGINEERING RESEARCH AND CONSULTING INC(ERC INC) EDWARDS AFB CA
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| Partial contents: Polynitrogen Chemistry: Recent Development in Pentazole and Polyazide Chemistry, Why Polynitrogen Compounds?, Geometry of the N5+ cation , (In) Compatabillty of N5+, New Polynitrogen Anions as Counterparts for N5+, Synthetic Challenge How do we make These New Anions??, Formation and Stabillty of Sllyl Diazonium Salts, Synthesis of Aryldiazonium Salts, Pentazole Formation.. Not a Trivial Chore!!!, Identification of Arylpentazoles, Cleavage of the Aryl-Pentazole Bond with Retention of the Pentazole ... |
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| Effect of Ligand Coordination on Complex Formation: Synthesis and Structural Studies of Metal(I) Salts Containing the N(SO2CF3)2 and OTeF5 Groups |
23 MAR 2004 |
40 pages |
| Authors:
Ashwani Vij; Vandana Vij; William W. Wilson; Fook S. Tham; ENGINEERING RESEARCH AND CONSULTING INCHUNTSVILLE AL
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| The cisoid form is less common. In the CCDC, only 6 structures show this conformation where as the transiod form occurs in 15 remaining structures The cisoid conformation results from stronger cation-anion interaction The cisoid exclusively when anion is chelated to the metal center The transoid form dominates in structures containing a free anion NO structure known with both cisoid AND transoid geometry |
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| Experimental and Theoretical Study of 1.5-Diamino-4-H-Tetrazolium Perchlorate |
2004 |
29 pages |
| Authors:
Greg Drake; Tommy Hawkings; Leslie Hall; Jerry Boatz; Ashwani Vij; AIR FORCE RESEARCH LAB EDWARDS AFB CA SPACE AND MISSILE PROPULSION DIV
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| The synthesis and characterization of 1 ,5-diamino- 1,2,3 ,4- tetrazolium perchlorate were carried out. Experimental evidence strongly supports the protonation of a nitrogen atom of the tetrazole ring, including the structure observed in a single crystal x-ray diffraction study of the title compound. Quantum chemical calculations were performed at the CCSD(T)/6- 311G(2df,p)//MP2/6-311G(d,p) level of theory to determine the relative energies of all possible N-protonated structures of the 1,5.-diamino- 1,2,3,4-tetrazole ring. ... |
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| 1-Alkyl-4-Amino-1.2.4-Triazolium Salts, New Families of Ionic Liquids |
01 DEC 2003 |
28 pages |
| Authors:
Greg W. Drake; Tommy Hawkins; Kerri Tollison; Leslie Hall; Ashwani Vij; AIR FORCE RESEARCH LAB EDWARDS AFB CA MOTOR BRANCH
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| New classes of ionic liquids based upon the halide and nitrate salts of 1-alkyl substituted-4 amino-1,2,4-triazolium cations (n-alkyl =methyl -decyl, isopropyl, ally, and methylcylcopropyl) have been synthesized, characterized by vibrational spectra, multinuclear nmr, elemental analysis, and DSC studies. Single crystal x-ray diffraction studies were carried out on 1-isopropyl-4- amino-1,2,4-triazolium bromide, 1 -ethyl-4-amino- 1 ,2,4-triazolium bromide, 1 - n-propyl-4-amino- 1 ,2,4-triazolium bromide, 1-n- hexyl-4-amino-1 ,2,4- triazolium bromide, and 1-n-heptyl-4-amino-1,2,4-triazolium bromide, as ... |
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| Methyl Tin(IV) Derivatives of HOTeF5 and HN(SO2CF3)2 |
11 SEP 2003 |
19 pages |
| Authors:
Ashwani Vij; William W. Wilson; Vandana Vij; Jerry A. Boatz; Robert C. Corley; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE
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| New Ionic Liquids |
09 SEP 2003 |
28 pages |
| Authors:
Greg Drake; Tommy Hawkins; Kerri Tollison; Leslie Hall; Ashwani Vij; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE
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| Preparation and Characterization of the Argentates: Ag?P(CF3)2!2(-), Ag?(mu-P(CF3)2)M(CO)5!2(-) (M = Cr, W) and Ag?mu-P(C6F5)2)W(CO)5!2(-): X-Ray Crystal Structure of K(18-Crown-6)Ag?mu-P(CF3)2)Cr(CO)5!2 |
16 JUL 2003 |
54 pages |
| Authors:
Berthold Hoge; Christoph Thoesen; Tobias Herrmann; Ashwani Vij; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE
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| The novel bis?bis(trifluoromethyl)phosphanido !argentate, Ag(P(CF3) 2!2(-), is obtained via the reaction of HP(CF3)2 with Ag(CN)2(-) and isolated as its K(18-crown-6) salt. If the cyclic phosphane (PCF3)4 is reacted with a slight excess of K(18-crown-6)Ag?P(CF3)2!2 a selective insertion of one PCF3 unit into each silver phosphorus bond is observed, giving NMR spectroscopic evidence for the Ag?P(CF3)P(CF3)2!2(-) ion. On treatment of the phosphane complexes M(CO) 5PH(CF3)2 (M= Cr, W) with K(18- crown-6)Ag(CN)2 ... |
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| Polynitrogen Chemistry |
21 APR 2003 |
3 pages |
| Authors:
Karl Christie; William Wilson; Ashwani Vij; Vandana Vij; Robert Corley; ENGINEERING RESEARCH AND CONSULTING INC(ERC INC) EDWARDS AFB CA
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| Under combined DARPA, AFOSR, NSF, and DOE sponsorship, we have continued our work in polynitrogen chemistry. We have successfully prepared and characterized numerous polyazido compounds, such as As(N3)3, Sb(N3)3, As(N3)5, Sb(N3)5, As(N3)6(-), Sb(N3)6(-), Te(N3)4, Te(N3)6(2-) P(N3)6(-), and B(N3)4(-), and have studied the combination of N5(+) with some of these among. Most of these compounds are extremely energetic and shock sensitive. We have studied the reactions of the NF4(+) and N2F3(+) ... |
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| Polynitrogen Chemistry. Preparation and Characterization of (N5)2SnF6, N5SnF5, and N5B(CF3)4 |
21 MAR 2003 |
22 pages |
| Authors:
William W. Wilson; Ashwani Vij; Vandana Vij; Eduard Bernhardt; Karl O. Christe; ENGINEERING RESEARCH AND CONSULTING INC(ERC INC) EDWARDS AFB CA
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| The successful synthesis of the 2:1 salt (N5+)2SnF6(2-) demonstrates that compounds with touching polynitrogen cations can be prepared, and that the synthesis of an ionic, all nitrogen compound is in principal possible. This paper also shows that N5+ salts, other than N5SbF6 and N5AsF6, can be prepared by metathetical reactions. This method was applied to the syntheses of N5B(CF3) 4, N5+SnF(5), and (N5(+))2SnF6(2-). |
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| On the Existence of FN5, a Theoretical and Experimental Study |
11 FEB 2003 |
38 pages |
| Authors:
Heather M. Netzloff; Mark S. Gordon; Karl Christe; William W. Wilson; Ashwani Vij; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE WEST
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| The possible existence of FN(5) was studied by ab initio electronic structure theory. Calculations were carried out at the MP2/6-31+G(d) and CCSD(T) /aug-cc-pVDZ levels of theory for the N(5)+AsF(6) ion pair and its decomposition to FN(5) and AsF(5). Six different vibrationally stable isomers of FN(5) were identified. Intrinsic reaction coordinate (IRC) and dynamic reaction path (DRP) calculations were used to study the isomerization of FN(5) and its decomposition to FN(3) ... |
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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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| Methyl Tin(IV) Derivatives of HOTeF5 and HN(SO2CF3)2: A Solution Multi- NMR Study and X-ray Crystal Structures of (CH3)2SnC1(OTeF5) and (CH3)3Sn(H2O) 2N(SO2CF3)2 |
03 JAN 2003 |
53 pages |
| Authors:
Ashwani Vij; William W. Wilson; Vandana Vij; Robert C. Corley; Fook S. Tham; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE WEST
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| The new tin(IV) species, (CH3)2SnCl(OTeF5), was prepared via solvolysis of (CH3)3SnCl in HOTeF5 or from the reaction of (CH3)3SnCl with ClOTeF5 and was characterized by NMR and vibrational spectroscopy, mass spectrometry, and single crystal X-ray diffraction. (CH3)2SnCl(OTeF5) crystallizes in the monoclinic space group P2(sub 1)/n (a = 5.8204(8) A, b =10. 782(1) A, c =15.493(2) A, beta=91.958(2), V =971.7(2) A (exp 3), Z = 4). NMR spectroscopy of (CH3)3SnX, prepared ... |
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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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| Enthalpies of Formation of Gas Phase N3, N3(-), N3(+), and N5(-) from Ab Initio Molecular Orbital Theory, Stability( Predictions for N5(+) N3(-) and N5(+) N5(-), and Experimental Evidence for the Instability of N5(+) N3(-) |
2003 |
36 pages |
| Authors:
David A. Dixon; Davied Feller; Karl O. Christe; William W. Wilson; Ashwani Vij; ENGINEERING RESEARCH AND CONSULTING INC(ERC INC) EDWARDS AFB CA
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| Ab initio molecular orbital theory has been used to calculate accurate enthalpies of formation and adiabatic electron affinities or ionization potentials for N3, N3(-), N5(+), and N5(-) from total atomization energies. Born-Haber cycle calculations, using estimated lattice energies and the adiabatic ionization potentials of the anions and electron affinities of the cations, permit for the first time reliable stability predictions for the hypothetical N5(+) N3(-) and N5(+)N5(-) salts. Contrary to ... |
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| Structures of the BrF4(+) and IF4(+) Cations |
AUG 2002 |
39 pages |
| Authors:
Karl Christe; Ashwani Vij; Fook S. Tham; Vandana Vij; William W. Wilson; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE WEST
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| The large discrepancies between the calculated and observed structures for BrF4(+) and IF4(+) (J. Am. Chem. Soc. 2001, 123, 6338) prompted a redetermination of the crystal structures of BrF4(+)Sb2F11(-) (monoclinic, P2 sub 1/c, a = 5.2289(6) A, b = 14.510(2) A, c = 14.194(2) A, * = 90.280(1)(sup o) , Z = 4) and IF4(+)SbF6(-) (orthorhombic, Ibca, a = 8.2702(9) A, b = 8.3115(9) A, c = 20.607(2) A, z ... |
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| Synthesis and Structural Characterization of Nitrogen Containing High Energy Density Materials |
18 JUN 2002 |
3 pages |
| Authors:
Karl O. Christe; Ashwani Vij; Vandana Vij; William W. Wilson; Fook S. Tham; ENGINEERING RESEARCH AND CONSULTING INCEDWARDS AFB CA
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| In this paper we report the crystal structures of the novel N5+ cation in N5+Sb2F11-, which is the first stable polynitrogen species to be discovered in a century since the discovery of the azide ion. |
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| Nitrogen Fluoride Chemistry |
12 JUN 2002 |
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| Authors:
Ashwani Vij; William Wilson; Vandana Vij; Karl Christe; F. Tham; ENGINEERING RESEARCH AND CONSULTING INCEDWARDS AFB CA
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 | The isomerization of trans-N2F2 to cis-N2F2 going through N2F(+) asF6(-) is unpredictable, erratic, requires 2 steps, and consumes an equimolar amount of AsF5. It was found that catalytic amounts of SbF5 at 3OC can achieve this isomerization, but still result in substantial N2F2 losses due to N2F(+) SbF6(-) formation. When the reaction is carried out at 60C, surprisingly NF4(+) SbF6(-).nSbF5 is formed. The crystal structures of N2F(+)SbF6(-) (disordered), N2F(+)SbF6(-) (disordered), ... |
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| Studies on the Generation of the Pentazole Anion and Singlet-Delta Molecular Oxygen |
09 MAY 2002 |
3 pages |
| Authors:
Karl O. Christe; William W. Wilson; Ashwani Vij; Vandana Vij; Angelo Alfano; ENGINEERING RESEARCH AND CONSULTING INCEDWARDS AFB CA
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| Under combined DARPA, AFOSR and NSF sponsorship, we have discovered, in 1999, the novel polynitrogen cation, N5+. |
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| Experimental Detection of the Pentazole Anion, N5(-) |
01 APR 2002 |
13 pages |
| Authors:
Ashwani Vij; James G. Pavlovich; William W. Wilson; Karl O. Christe; CALIFORNIA UNIV SANTA BARBARA DEPT OF CHEMISTRY
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| The pentazole anion has been generated from para- hydroxyphenylpentazole and identified by electrospray ionization mass spectrometry. Whereas at low collision voltages the para-phenoxypentazole anion undergoes stepwise N2 elimination generating the corresponding azide and nitrene, at high collision voltages the N5(-) anion is formed. Fragmentation of the pentazole anion produces the N3(-) anion as the principal negative ion. These experiments provide the first experimental proof for the existence of the pentazole ... |
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| Polynitrogen Chemistry and the Pursuit of New High Energy Density Materials |
13 APR 2001 |
3 pages |
| Authors:
Karl O. Christe; William W. Wilson; Ashwani Vij; Vandana Vij; Jeffrey A. Sheehy; ENGINEERING RESEARCH AND CONSULTING INC(ERC INC) EDWARDS AFB CA
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| The goal of this AFOSR program is the synthesis of novel polynitrogen-derived HEDM compounds, exploiting the synergism between theory and synthesis. Under combined DARPA, AFOSR and NSF sponsorship, we have discovered in 1999 the novel polynitrogen compound, N5(+)AsF6(-). The N5(+) cation is only the third known, homoleptic polynitrogen species that can be prepared and isolated in bulk, the other two being N2 and the azide anion. N5(+)AsF6(-) was found to ... |
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| Polynitrogen Chemistry, Synthesis, Characterization, and Crystal Structure of Surprisingly Stable Fluoroantimonate Salts of N5(+) |
01 MAR 2001 |
48 pages |
| Authors:
Ashwani Vij; William W. Wilson; Vandana Vij; Fook S. Tham; Karl O. Christe; UNIVERSITY OF SOUTHERN CALIFORNIA LOS ANGELES LOKER HYDROCARBON RESEARCH INST
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| The new N5(+) salt, N5(+)SbF6(-), was prepared from N2F(+)SbF6(-) and HN3 in anhydrous HF solution. The white solid is surprisingly stable, decomposing only at 70 deg C, and is relatively insensitive to impact. Its vibrational spectrum exhibits all nine fundamentals with frequencies that are in excellent agreement with the theoretical calculations for a five-atomic V-shaped ion of C2v symmetry. The N5(+)Sb2F11(-) salt was also prepared and its crystal structure was ... |
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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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| Theory and Synthesis of New High Energy Density Materials |
03 OCT 2000 |
5 pages |
| Authors:
Karl O. Christe; William W. Wilson; Ashwani Vij; Jeffrey A. Sheehy; Jerry A. Boatz; AIR FORCE RESEARCH LAB EDWARDS AFB CA SPACE AND MISSILE PROPULSION DIV
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| The aim of this AFOSR program is the synthesis of novel HEDM compounds, exploiting the synergism between theory and synthesis. Theoretical calculations are routinely used to guide the synthesis efforts and to facilitate the identification and characterization of the products. |
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| Chemistry of N-F Containing HEDM Materials and on Lewis Acidity of LiF |
03 OCT 2000 |
4 pages |
| Authors:
Vandana Vij; Ashwani Vij; William W. Wilson; Karl O. Christe; Jeffery A. Sheehy; AIR FORCE RESEARCH LAB EDWARDS AFB CA SPACE AND MISSILE PROPULSION DIV
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| The recent isolation of the N5+ cation is one of the most amazing discoveries of modern chemistry. This statement is justified by the fact that this is the first all nitrogen homoleptic species to be isolated in more than a century, and only the third known species of this kind besides atmospheric nitrogen (N2) and the azide ion (N3(-)). The N5(+)AsF6(-) salt is only marginally stable at room temperature. In ... |
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| Method for Solving Some Disordered Crystal Structures and its Application to the Structures of NF2O+ and SO2F- |
SEP 2000 |
3 pages |
| Authors:
Karl O. Christe; Ashwani Vij; Rudiger Mews; Xiongzhi Zhang; Jerry Boatz; AIR FORCE RESEARCH LAB EDWARDS AFB CA SPACE AND MISSILE PROPULSION DIV
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| Oxygen and fluorine ligands are similar in size and frequently exhibit positional disorder in the crystal structures of oxofluorides, resulting in a partial or complete averaging of the observed bond lengths and angles. The failure to recognize the presence of disorder has resulted in the publication of numerous incorrect structures, while the recognition of disorder problems has generally prompted researchers to abandon these data sets. In this paper, a method ... |
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| Recent Progress in Nitrogen Fluoride Chemistry |
SEP 2000 |
3 pages |
| Authors:
Vandana Vij; Ashwani Vij; William W. Wilson; Karl O. Christe; AIR FORCE RESEARCH LAB EDWARDS AFB CA SPACE AND MISSILE PROPULSION DIV
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| For the preparation of N5+ salts on a larger scale, it was necessary to prepare the corresponding precursors in an efficient manner and in large quantities. In this paper, process improvements in this direction are described. Furthermore, the catalytic conversion of trans-N2F2 to its cis-isomer is discussed. Also discovered during the isomerization studies was a novel synthetic route to NF4+ salts at relatively low temperature and pressure. A structural analysis ... |
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| The Structure of the SO2F Anion, A Problem Case |
19 JUN 2000 |
39 pages |
| Authors:
Paul G. Watson; Tobias Borrmann; Ashwani Vij; Jerry A. Boatz; Karl O. Christe; AIR FORCE RESEARCH LAB EDWARDS AFB CA SPACE AND MISSILE PROPULSION DIV
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| Recently, room-temperature crystal structures of SO2F(-) in its K(+) and Rb(+) salts were published in Z. Among. Allg. Chem. 1999, 625, 385 and claimed to represent the first reliable geometries for SO2F(-). However, their almost identical 5-O and S-F bond lengths and O-S-O and O-S-F bond angles are in sharp contrast to the results from theoretical calculations. To clarify this discrepancy, the new (CH3)2N3SO(+) and the known N(CM3)4(+), (CH3)2N3S(+) and ... |
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Reports by Author
