WorldCat Identities

Christe, Karl O.

Overview
Works: 88 works in 107 publications in 1 language and 107 library holdings
Publication Timeline
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Most widely held works by Karl O Christe
HIGH ENERGY OXIDIZERS( Book )

4 editions published between 1965 and 1966 in English and held by 4 WorldCat member libraries worldwide

Under glow discharge, F2, NF3, and AsF5 combine to form a thermally stable (but easily hydrolyzable) white solid. IR spectroscopy, elemental analysis, and preliminary thermal decomposition (at 250 degrees) indicated the probable formation of NF4+AsF6-. Work is presently aimed at obtaining Raman spectroscopy, X-ray, DTA, NMR, and density measurements to strengthen initial evidence for the existence of NF4+AsF6-. Data accumulated during attempts to obtain the Raman spectrum of ClF2+AsF6- in IF5 were inconclusive. (Author)
Experimental Evidence for Linear Metal-Azide Bonds. The Binary Group 5 Azides Nb(N3)5, Ta(N3)5, [Nb(N3)6]- and [Ta(N3)6]-, and 1:1 Adducts of Nb(N3)5 and Ta(N3)5 with CH3CN (PREPRINT)( )

3 editions published between 2005 and 2006 in English and held by 3 WorldCat member libraries worldwide

Whereas the existence of numerous binary transition metal azido-complexes has been reported, no binary Group 5 azides are known. Only a limited number of partially azide-substituted compounds of vanadium, niobium and tantalum have previously been reported. In this paper, we wish to communicate the synthesis and characterization of Nb(N3)5, Ta(N3)5 and their 1:1 adducts with CH3CN, and of the anions [Nb(N3)6]- and [Ta(N3)6]-. The crystal structures of Nb(N3)5-CH3CN and [PPh4][Nb(N3)6] and the first experimental evidence for the existence of azido compounds with linear metal-N-N bonds are also reported
Preparation, Characterization, and Crystal Structures of the SO(3)NHF- and SO(3)NF(2)-Anions (PREPRINT)( )

3 editions published in 2006 in English and held by 3 WorldCat member libraries worldwide

Recently, a new class of high-energy-containing materials, gem-bis(difluoramino)-substituted heterocyclic nitramines, has gained attention as high-energy oxidizers: HNFX and TNFX have been successfully synthesized under strongly acidic conditions from their corresponding ketone derivatives using an excess of difluoramine. HNF2 is an unpredictably shock-sensitive and thermally unstable, gaseous compound which can be generated from different precursors, e.g., tetrafluorohydrazine, N, N-difluorourea, N, N-difluorocarbamates, or trityldifluoramine. Out of these precursors, only trityldifluoramine is a stable storable solid. However, it is not useful as a general reagent for the preparation of larger quantities of gem-bis(difluoramines) because its synthesis requires the use of expensive N2F4 which is commercially unavailable and must be prepared from difluoramine, and of equivalent amounts of mercury in an organic solvent. The use of mercury presents environmental problems, and working with N2F4 in an organic solvent can be hazardous. Therefore, it is highly desirable to develop a stable, solid, readily accessible difluoramine source. Obvious candidates for HNF2 sources were difluorosulfamate salts. Although the parent free acid, HOSO2NF2, had been known since 1961 and has been widely used as a difluoroaminating reagent, no reports could be found on the existence of its salts. In this paper, we report the results from two independent studies
Inorganic Halogen Oxidizer Research by K. O Christe( Book )

2 editions published between 1972 and 1973 in English and held by 2 WorldCat member libraries worldwide

The report describes the activities during the past year at Rocketdyne in the area of halogen oxidizer chemistry. A large number of compound types were investigated including halogen perchlorate chemistry, halogen oxyfluoride synthesis, PtF6 chemistry, new fluorination catalysts, novel energetic cation synthesis, halogen oxide chemistry and halogen fluoride reactions. Most of the data have been summarized in manuscript form. A number of papers written during the year are presented in full. The compounds researched include ClF3O2, ClF6(+), ClF5O, ClF, Ozone, Cl2O4, CsIF4
Theory and Synthesis of New High Energy Density Materials( )

2 editions published between 1998 and 2000 in English and held by 2 WorldCat member libraries worldwide

Efforts are described to combine the NF4+ cation with highly energetic anions, such as NO(2), NO(3), and N(NO2)2. In the case of NO(3), the NO(3) anion was fluorinated already at very low temperatures by NF(4) to give fluorine nitrate in high yield. In the case of NO(2), the reaction with NF(4) yielded an unknown unstable decomposition product in low yield, but the reaction was very difficult to control and consistently exploded. In the case of N(NO2)2, again no stable salt was formed, and a thermally unstable decomposition product, probably FN(NO2)2, was observed by (19)FNMR spectroscopy
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( Book )

2 editions published in 2004 in English and held by 2 WorldCat member libraries worldwide

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 crystal structure of W(N3)6 and the controlled nitrogen loss from the heptaazido anions to give nitrido-teraazido anions. The NMo(N3)4- ion is already known but had been obtained by a different method
History of the AFRL/USC DARPA Program on Polynitrogen Chemistry. Volume 2( Book )

2 editions published in 2004 in English and held by 2 WorldCat member libraries worldwide

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 prepare tetrahedral N4. In response to this proposal and upon urging from the Air Force Research Laboratory, DARPA issued a broad solicitation for experimental efforts and funded eight programs in the polynitrogen area. One of these programs was the effort at the Air Force Research Laboratory at Edwards Air Force Base. This effort was led by Karl Christe, who is also a Research Professor at the Loker Research Institute of the University of Southern California in Los Angeles, CA, and was expanded one year later to include a program at USC. Because of the overlap and close cooperation between these two programs, the results are summarized in a single report
Polyazide Chemistry: Synthesis and Properties of [Nb(N3)7]2- and [Ta(N3)7]2- (PREPRINT)( Book )

2 editions published in 2006 in English and held by 2 WorldCat member libraries worldwide

During the last decade, inorganic polyazido compounds have received much attention. Besides being of academic interest, azides and polyazides are viable candidates for high energy-density materials (HEDM). The azido group is very energetic and polyazides are highly endothermic compounds, whose energy content increases with an increasing number of azido ligands. It is, therefore, not surprising that the synthesis of molecules with a high number of azido groups is very challenging due to their explosive nature and shock sensitivity. Despite such obstacles, a number of pentaazido and anionic hexaazido compounds had been reported. Very recently, unprecedented neutral hexaazido species M(N3)6 (M = Mo, W) have been prepared, and in case of W(N3)6 also structurally characterized. Treatment of M(N3)6 (M = Mo, W) with ionic azides yielded the first binary heptaazido compounds
High Energy Density Material Chemistry( Book )

2 editions published in 2006 in English and held by 2 WorldCat member libraries worldwide

The overall objectives of this research are the syntheses and characterization of polynitrogen, high-nitrogen and high-oxygen energetic materials, useful as propellants or explosives ingredients. Excellent results were obtained in all areas and are summarized in 38 pubications and 2 patents. The chemistry of N5+ was developed and 13 new N5+ salts were prepared and characterized. It was demonstrated that N5+ cations can be combined with doubly charged anions, thereby doubling the N5+ content of a salt. Furthermore, it was shown that N5+ can be combined with highly energetic counter-ions. Another novel polynitrogen ion, discovered under this program by electrospray ion mass spectroscopy, is the cyclo-N5 anion. Two other novel polynitrogen species, were prepared and characterized. A new method for the processing of nitrogen NMR data with greatly improved signal to noise ratios was developed and successftilly applied to N5+. A large number of novel poiyazides were prepared and characterized. A new concept for liquid monopropellants, based on oxygen-balanced energetic ionic liquids, was developed and successfiilly demonstrated. A new stable reagent, for the introduction of gem-bis NF2 groups was developed. A new solid-gas process, which avoids liquid phase quenching was invented for generating singlet delta oxygen for the COIL laser
Synthesis and Characterization of z-N3NFO+ and e-N3NFO+ (Preprint)( Book )

2 editions published in 2007 in English and held by 2 WorldCat member libraries worldwide

Only three well characterized stable nitrogen fluoride oxide molecules, FNO, FNO2 and NF3O, and one ion, NF2O+, are known in which the fluorine and oxygen atoms are directly bonded to the nitrogen atom. In this paper, we report the synthesis and characterization of N3NOF+, a novel stable nitrogen fluoride oxide cation which can exist in the form of two different configurational isomers
Crystal Structure of Hexamethylguanidinium Hexafluorosilicate Hexahydrate( )

2 editions published between 1998 and 1999 in English and held by 2 WorldCat member libraries worldwide

Single crystals of the hexamethylguanidinium hexafluorosilicate hexahydrate salt, C(NMe2)32(+)SiF6(2- )(dot) 6H2O, were isolated when a product, obtained by water removal from aqueous C(NMe2)3F in a glass vessel, was recrystallized from CH3OH. The crystal structure of this salt was determined, and the structure of the free hexamethylguanidinium cation was calculated, showing that the propeller-shaped structure of the hexamethylguanidinium cation is not caused by solid state effects but is the true minimum energy structure
Polyazide Chemistry Preparation and Characterization of As(N3)5, Sb(N3)5 and P(C6H5)4Sb(N3)6( Book )

2 editions published in 2004 in English and held by 2 WorldCat member libraries worldwide

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 explosions that were described as "so intense that only pulverized glass remained." Furthermore, As(N3)5 was predicted to be a "highly unstable compound," based on its analogy to AsCl5. In this paper, we wish to communicate the synthesis and characterization of neat As(N3)5 and Sb(N3)5, and their conversion to the As(N3)6 and Sb(N3)6 anions, respectively. We also report the crystal structure of P(C6H5)4Sb(N3)6
Synthesis and Characterization of Silyldichloramines, Their Reactions with F- Ions, Stability of N2CI2 and NCI2(-), and Formation of NCI3 (Postprint)( Book )

2 editions published in 2007 in English and held by 2 WorldCat member libraries worldwide

Only two silyldichloramines, (C6H5)3SiNCl2 and (CH3)3SiNCl2, have been reported in the literature. The synthesis of the former was successfully repeated, and its structure was established by single crystal X-ray diffraction and vibrational spectroscopy. Attempts to prepare (CH3)3SiNCl2 were unsuccessful, however, a new trialkylsilyldichloramine, t-BuMe2Si-NCl2, was prepared and characterized by Raman and multinuclear NMR spectroscopy. The reaction of t-BuMe2SiNCl2 with (CH3)4NF in CHF3 solution at -78 deg C, followed by removal of all volatile products at -30 deg C, produced the expected t-BuMe2SiF by-product and a white solid consisting of NCl3 absorbed on Me4NCl. The NCl3 could be reversibly desorbed from the substrate and was identified as a neat liquid at room temperature by Raman spectroscopy. The observed final reaction products are consistent with the formation of an unstable N(CH3)4+NCl2( - ) intermediate which decomposes to N(CH3)4+Cl( - ) and NCl molecules which can dimerize to N2Cl2. Theoretical calculations confirm that NCl2( - ) can readily lose Cl( - ) and that N2Cl2 also possesses a low barrier towards loss of N2 to give chlorine atoms and, thus, can account for the formation of NCl3
Synthesis and Characterization of Silyldichloramines, Their Reactions with F Ions, Stability of N2Cl(2) and NCl(2), and Formation of NCl(3) (PREPRINT)( Book )

2 editions published in 2007 in English and held by 2 WorldCat member libraries worldwide

Only two silyldichloramines, (C6H5)3SiNCl(2) and (CH3)3SiNCl(2), have been reported in the literature. The synthesis of the former was successfully repeated, and its structure was established by single crystal X-ray diffraction and vibrational spectroscopy. Attempts to prepare (CH3)3SiNCl(2) were unsuccessful, however, a new trialkylsilyldichloramine, t-BuMe2Si-NCl(2), was prepared and characterized by Raman and multinuclear NMR spectroscopy. The reaction of t-BuMe2SiNCl(2) with (CH3)4NF in CHF3 solution at -78 deg. C, followed by removal of all volatile products at -30 deg. C, produced the expected t-BuMe2SiF by-product and a white solid consisting of NCl(3) absorbed on Me4NCl. The NCl(3) could be reversibly desorbed from the substrate and was identified as a neat liquid at room temperature by Raman spectroscopy. The observed final reaction products are consistent with the formation of an unstable N(CH3)4+NCl(2)- intermediate which decomposes to N(CH3)4+Cl- and NCl molecules which can dimerize to N2Cl(2). Theoretical calculations confirm that NCl(2)- can readily lose Cl- and that N2Cl(2) also possesses a low barrier towards loss of N2 to give chlorine atoms and, thus, can account for the formation of NCl(3)
All Nitrogen or High Nitrogen Compounds as High Energy Density Materials( Book )

2 editions published in 2005 in English and held by 2 WorldCat member libraries worldwide

The goals of this research were the identification of potential polynitrogen HEDM candidates and the design of strategies and experimental approaches for their attempted syntheses. This program was a Phase I Small Business Technology Transfer Program (STTR) contract with the Air Force Office of Scientific Research (Contract FA9550-04-C-0112). It was carried by ERC- Incorporated as the Small Business and the University of Southern California as the Academic Institution. The following goals have been accomplished: 1. The N3+ cation was identified as a promising HEDM target, and the feasibility of different synthetic approaches was evaluated. 2. It was shown that the previously reported claim for a bulk synthesis of N(sub 5)- is invalid, and theoretical calculations were carried out to define favorable approaches for its synthesis. 3. The usefulness of a novel nitrogen-NMR technique for recording 15N-spectra in natural abundance was demonstrated for N(SUB 5)+ and will be very useful for the identification of new polynitrogens. 4. The novel cation, N(sub 2)CN+, has been tentatively identified. 5. Numerous new polyazides have been prepared and characterized and demonstrate the potential of this family of compounds. 6. The novel N(sub 3)NOF+ cation has been prepared and characterized. Tentative evidence has been obtained for the existence of a new exciting, room- temperature-stable (N3)(sub2)N0+ cation. 7. The feasibility of using HOF for the oxygenation of nitrogen atoms was confirmed and has potential applications to polynitrogen chemistry
Relative Abilities of Fluorine and Chlorine to Stabilize Carbenium Ions. Crystal Structures of Two Fluoro-Substituted Carbocations and of As2F11( )

1 edition published in 1999 in English and held by 1 WorldCat member library worldwide

The first crystal structures of fluoro-substituted carbocations without heteroatom stabilization and of the As2F11( - ) anion are reported. The experimental geometries of the carbenium ions in (CH3)2CF(+)asF6( - ), (M-CF3C6H4)(C6H5)CF(+)asF6( - ) and (M-CF3C6H4)(C6H5)CF(+)as2F11( - ) and their comparison with that of the (0-ClC6H4)(C6H5)CCl(+) cation show that, in accord with previous theoretical calculations, chlorine stabilizes carbenium ions more efficiently than fluorine. The apparent discrepancy between these findings and a previously reached conclusion, based on an analysis of sup 13 C NMR chemical shift difference data, are reconciled by using the direct sup 13 C chemical shifts for judging the donor strength of a ligand. The sup 13 C and sup 19 F NMR spectra of the (M-CF3C6H4)(C6H5)CF(+) cation were recorded and analyzed with the help of RHF/6-31G(d, p) calculations using the GIAO method. In each of the three fluoro-substituted carbocation crystal structures studied, the carbenium centers are further stabilized by forming two fluorine bridges with the anions, resulting in pseudo-trigonal bipyramidal environments around the carbenium centers. The F5As-F-AsF5( - ) anion in (M-CF3C6H4)(C6H5)CF(+)as2F11( - ) possesses a symmetric fluorine bridge with an As-F-As angle of 156.5(13) deg and staggered AsF4 groups
Perfluoroammonium Salts of Metal Heptafluoride Anions( Book )

1 edition published in 1981 in English and held by 1 WorldCat member library worldwide

Synthesis and Properties of NF4(+)SO3F( - )( Book )

1 edition published in 1980 in English and held by 1 WorldCat member library worldwide

A New Synthesis of Anhydrous Cesium Salts( )

1 edition published in 2001 in English and held by 1 WorldCat member library worldwide

Contrary to ammonium salts many cesium salts are extremely hygroscopic. Consequently, anhydrous ammonium salts are readily available in anhydrous form by neutralizing the corresponding acids with ammonia, but their conversion to anhydrous cesium salts is difficult
Polynitrogen Chemistry: Recent Development in Pentazole and Polyazide Chemistry( )

1 edition published in 2004 in English and held by 1 WorldCat member library worldwide

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 Ring, MSMS of the Parent Ion Peak, Chemical Cleavage of the C-N Bond, Aryl-pentazole bond cleavage: N5 anion in Solution, Subsequent Decomposition of the Pentazole Anion, Pentazoles with Heterocyclic Substituents, 15N NMR of 2-pentazoly!-4, 5-dicyano- imidazole, Pentazolate Anion in Solution?, Chronology of the Pentazolate Anion, What are "normal" N-N distances in azides?, Abnormalities in azide distances: Artifacts or Structural Contaminants?, Reactivity of hexachioroantimonate (VI) - with Trimethylsilylazide, The tetraphenylarsonium antimonychioride azide case
 
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English (39)