7789-25-5Relevant articles and documents
A quantum mechanical, time-dependent wave packet interpretation of the diffuse structures in the S0 --> S1 absorption spectrum of FNO: Coexistence of direct and indirect dissociation
Suter, Hans Ulrich,Huber, J. Robert,Dirke, Michael von,Untch, Agathe,Schinke, Reinhard
, p. 6727 - 6734 (1992)
We have investigated the photodissociation of FNO in the first absorption band (S0 --> S1) by a two-dimensional wave packet study based on an ab initio potential energy surface.The quantum chemical calculations were performed in the multiconfiguration self-consistent field (MCSCF) approach including the N-O and the F-NO bond distances with the FNO bond angle being fixed.The most striking feature of the time-dependent dynamical analysis is a bifurcation of the wave packet near the Franck-Condon point: while one part of the wave packet leaves the inner region of the potential energy surface very rapidly, a second part remains trapped for several periods in an extremely shallow well at short F-NO distances.The direct part leads to a broad background in the absorption spectrum while the trapped portion of the wave packet gives rise to relatively narrow resonances, i.e., well resolved diffuse vibrational structures.The bandwidth decreases with the degree of internal excitation.The calculated spectrum agrees well with the measured one.
SPECTRAL OUTPUT FROM A PREMIXED CHAIN REACTION cw HF LASER.
Stanton,Bien
, p. 3536 - 3540 (1980)
Spectral measurements of the output from a purely chemical chain reaction cw HF laser are presented. The laser is a subsonic H//2-F//2 flame, with supersonic premixing and spatially uniform initiation by a stationary normal shock. Initial chemical production of fluorine atoms is by the bimolecular reaction of F//2 with NO. The results indicate an approximate rate of 5 multiplied by 10** minus **1**3** plus or minus **0**. **5 cm**3/sec for deactivation of HF ( upsilon equals 2) by NO.
Experimental and theoretical studies of the reaction between CF3 and NO2 at 298 K
Pagsberg, Palle,Jodkowski, Jerzy T.,Ratajczak, Emil,Sillesen, Alfred
, p. 138 - 144 (1998)
The title reaction has been studied by pulse radiolysis combined with time-resolved infrared diode laser spectroscopy. The kinetics of CF3 were analysed taking into account the two competing reactions CF3+ CF3+M → C2F6+M (1) and CF3+NO2 → CF2O+FNO (2a). Based on studies of the yield and kinetics of CF3 we determined values of the absorption cross section, σ(CF3)=(1.96±0.20)×10-17 cm2 molecule-1 at 1263.567 cm-1 and the bimolecular rate constant, k1=(1.04±0.12)×10-11 cm3 molecule-1 s-1 with a bath gas pressure of 20 mbar at 298 K. Reaction (2a) was studied under pseudo-first-order conditions and the value of k2a=(1.53±0.20)×10-11 cm3 molecule-1 s-1 was found to be independent of bath gas pressure in the range 4-22 mbar. Based on the characteristic absorption spectra of the products, the branching ratio of reaction (2a) was found to be 0.95.
EFFICIENT PURELY CHEMICAL CW LASER OPERATION
COOL TA,STEPHENS RR
, p. 55 - 58 (1970)
Continuous-wave laser operation at 10. 6U has been achieved in the DF-CO//2 and HF- CO//2 molecular systems by purely chemical means. No external energy sources are required; both lasers operate solely by the simple mixing of bottled gases. Experimental r
Mapping of parent transition-state wave functions into product rotations: An experimental and theoretical investigation of the photodissociation of FNO
Ogai, Amy,Brandon, James,Reisler, Hanna,Suter, Hans Ulrich,Huber, J. Robert,et al.
, p. 6643 - 6653 (1992)
We study experimentally and theoretically reflection-type structures in the rotational distributions of NO following the photodissociation of FNO via excitation of the S1 state.Exciting quasibound states with zero quanta of bending vibration in the FNO(S1) state yields Gaussian-type rotational distributions, while excitation of states with one bending quantum leads to bimodal distributions.In the latter case, the ratio of the two intensity maxima depends on the number of NO stretching quanta in the S1 state.The accompanying calculations employing a three-dimensional ab initio potential energy surface for the S1 state of FNO are performed in the time-dependent wave packet approach.They reproduce the main features of the experimental distributions, especially the bimodality.The analysis of two-dimensional calculations for a frozen NO bond distance shows that the final rotational state distributions can be explained as the result of a dynamical mapping of the stationary wave function on the transition line onto the fragment rotational quantum number axis.Here the transition line is defined as the line which separates the inner part of the FNO(S1) potential energy surface from the strongly repulsive F + NO product channel.
Thermally persistent fluorosulfonyl nitrene and unexpected formation of the fluorosulfonyl radical
Zeng, Xiaoqing,Beckers, Helmut,Willner, Helge
, p. 2096 - 2099 (2013/04/23)
Thermally persistent triplet sulfonyl nitrene, FSO2N, was produced in the gas phase in high yields (up to 66%) by flash vacuum pyrolysis of FSO2N3. Surprisingly, no rearrangement of FSO 2N was observed, but the
Vibrational spectra of AuF5 complexes with nitrogen fluorides and oxofluorides
Nabiev, Sh. Sh.,Sokolov,Chaivanov
, p. 497 - 505 (2013/06/05)
Vibrational spectra and structural features of AuF5 complexes with nitrogen fluorides (NF3, N2F4) and oxofluorides (FNO, NF3O) are investigated. Vibrational frequency assignment in the solid phase and
Kinetics and mechanisms of the thermal gas-phase reactions of CF3OF and CF3OOCF3 with NO2
Czarnowski
, p. 83 - 94 (2007/10/03)
The kinetics of the reactions of CF3OF and CF3OOCF3 with NO2 have been investigated using a conventional static system. The reaction between CF3OF and NO2 has been studied in a quartz reactor in the temperature range of 313.2-334.2 K, varying the initial pressure of CF3OF between 19.4 and 165.2 Torr and that of NO2 + N2O4 between 18.2 and 179.2 Torr. Some experiments were made in presence of 506.5-600.8 Torr of N2. The total pressure had no influence on the reaction rate. COF2 and FNO2 were identified as reaction products. The expression obtained for the rate constant for the abstraction of fluorine atom from CF3OF by NO2 was: k1 = (1.1±0.2) × 109 exp(-16.4±1 kcal mol-1/ RT) dm3 mol-1 s-1. The reaction of CF3OOCF3 with NO2 has been studied in an aluminum reactor in the temperature range of 474.0-512.5 K, varying the initial pressure of CF3OOCF3 between 24.1 and 202.5 Torr and that of NO2 between 24.7 and 202.7 Torr. Several experiments were made in presence of 399.8-490.5 Torr of N2. The reaction rate was proportional to [CF3OOCF3]1/2. The reaction approached the first order with respect to NO2 at low pressure of NO2. Increasing the pressure of NO2, the ratio of the reaction rates increased more rapidly than the ratio of the corresponding concentrations of NO2. Three products were formed: COF2, FNO and O2. The expression obtained for the rate constant for the abstraction of the fluorine atom from the radical CF3O by NO2 was: k8 = (1.72±0.4) × 109 exp(-10.8±1 kcal mol-1/RT) dm3 mol-1 s-1. The mechanisms for both reactions were postulated. by Oldenbourg Wissenschaftsverlag, Muenchen.
Endothermic formation of a chemical bond by entropic stabilization: Difluoronitroxide radical in solid argon
Misochko, Eugenii Ya.,Akimov, Alexander V.,Goldschleger, Ilya U.,Boldyrev, Alexander I.,Wight, Charles A.
, p. 405 - 410 (2007/10/03)
Difluoronitroxide radical (F2NO) has been formed in solid argon matrices by successive addition of two diffusing F atoms to NO. This radical exists in dynamic equilibrium with a van der Waals complex (FFNO). Measurements of the equilibrium concentrations as a function of temperature show that the changes in enthalpy and the entropy associated with formation of the F2NO radical are ΔH = 1240 ± 180 J/mol and ΔS = 62 ± 10 J/(mol K). Because both these quantities are positive, the equilibrium favors F2NO only at elevated temperatures. This situation is a rare case in which formation of a chemical bond is stabilized only by an increase in the entropy of the system.
Seven-coordinated pnicogens. Synthesis and characterization of the SbF72- and BiF72- dianions and a theoretical study of the AsF72- dianion
Drake, Greg W.,Dixon, David A.,Sheehy, Jeffrey A.,Boatz, Jerry A.,Christe, Karl O.
, p. 8392 - 8400 (2007/10/03)
The novel seven-coordinated BiF72- and SbF72- dianions have been prepared and characterized. The Cs2BiF7, Rb2BiF7, K2BiF7, and Na2BiF7 salts were obtained in high yield by heating BiF5 with an excess of the corresponding alkali metal fluorides to about 250 °C. Attempts failed to prepare the corresponding BiF83- salts or Li2BiF7 under similar conditions. The [N(CH3)4]2BiF7 salt was obtained by the combination of excess N(CH3)4F with BiF5 in CH3CN solution at -31 °C. The (NO2)2BiF7 salt was prepared from BiF5 and a large excess of liquid FNO at -78 °C and decomposes at room temperature to NOBiF6 and FNO. The corresponding Cs2SbF7, K2SbF7, and [N(CH3)4]2SbF7 salts were also synthesized in a similar fashion, but Na2SbF7 was not formed. The pronounced fluoride ion affinity of SbF6- was further demonstrated by the formation of some Cs2SbF7 when dry CsF and CsSbF6 were ball-milled at room temperature. The BiF72- and SbF72- anions, which are the first examples of binary pnicogen compounds with coordination numbers in excess of six, were characterized by vibrational spectroscopy and ab initio electronic structure calculations. They possess pentagonal bipyramidal, highly fluxional structures of D(5h) symmetry, similar to those of IF7 and TeF7-, which are isoelectronic with SbF72-. Although our theoretical calculations indicate that AsF72- is also vibrationally stable, experiments to prepare this dianion were unsuccessful.
