ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Formation of CH(A 2Δ,B 2Σ−,C 2Σ+) by electron–ion recombination processes in the argon and krypton afterglow reactions of CH4 (1991)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 94 (1991), S. 1127-1133 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The CH(A–X,B–X,C–X) emission systems have been observed from the Ar and Kr afterglow reactions of CH4. A significant attenuation of the CH(A–X,B–X,C–X) emissions by an addition of SF6 into the discharge flow suggested that the CH(A,B,C) radicals are excited via secondary electron–ion recombination processes. Since the CH(A–X,B–X,C–X) emissions disappeared by trapping ionic active species in the discharge flow, the responsible active species for the CH(A,B,C) production were found to be Ar+ and/or (Ar+)* in the Ar flow and Kr+ and/or (Kr+)* in the Kr flow. The contribution of Ar+ and Kr+ was examined in the He afterglow, where Ar+ or Kr+ and slow electrons were simultaneously produced by the He(23S)/Ar,Kr Penning ionization. Although intense CH(A–X,B–X,C–X) emissions were observed from Ar+/CH4 where CH+n(n=2–4) were formed, they were absent from Kr+/CH4 where only CH+4 was produced. It was, therefore, concluded that CH+2 and/or CH+3 are important precursor ions for the CH(A,B,C) production. The intensity distribution of CH(A,B,C) and the CH(A,B) rovibrational distributions obtained in the Ar afterglow agreed with those through Ar+/CH4, indicating that Ar+/CH4 plays a significant role for the production of precursor ions in the Ar afterglow or (Ar+)*/CH4 provides the same precursor ions. Since the relative intensity of CH(A,B) and the rovibrational distributions of CH(A) in the Kr afterglow were different from those in the Ar afterglow, different electron–ion recombination processes dominantly take part in the CH(A,B) production.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.460018
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Thermal-energy chemiluminescent reaction of N(2D) with OCS: Nascent vibrational and rotational distributions of the NS(B 2Π) product (1988)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 89 (1988), S. 257-261 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: NS(B 2Π–X 2Π) chemiluminescence has been observed from the thermal-energy reaction between N(2D) atoms and OCS molecules under single collision conditions. The vibrational populations of NS(B) decrease monotonically with increasing vibrational quantum numbers from v'=0 to 4, while the rotational temperature is constant at about 1000 K for all vibrational levels. The observed vibrational distribution is more excited than the statistically predicted ones, suggesting that the reaction proceeds by a direct mode.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.455519
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Dissociative excitation of CH4 by collisions with helium active species (1991)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 94 (1991), S. 277-282 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Dissociative excitation of CH4 by collisions with He(2 3S), He+, and He+2 has been studied by observing CH(A 2Δ–X 2Πr, B 2Σ−–X 2Πr, and C 2Σ+–X 2Πr) and H (Balmer) emissions in the flowing afterglow and beam apparatus. The effect of SF6 addition into the He afterglow indicated that the formation of CH(A,B,C) in the flowing afterglow proceeds through both the primary He(2 3S)/CH4 reaction and a secondary electron–ion recombination reaction through the He+/CH4 and/or He+2/CH4 reactions. The emission rate constants of A–X, B–X, and C–X of CH, Hα, and Hβ produced from the He(2 3S)/CH4 reaction were determined to be 5.6, 1.5, 0.011, 0.46, and 0.072×10−13 cm3 s−1 in the beam experiment, respectively. The nascent vibrational distribution of CH(A) from He(2 3S)/CH4 was determined as N0:N1=100:37±5. The rotational distributions were expressed by single Boltzmann temperatures of 3200±200 and 2600±300 K for v'=0,1 of CH(A) and 3300±200 K for v'=0 of CH(B).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.460732
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    The SiH+(A 1Π–X 1Σ+) emission produced from the thermal energy reaction of He+ with SiH4 under single collision conditions (1987)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 86 (1987), S. 4952-4956 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: A flowing afterglow reactor has been coupled to a low-pressure chamber for an optical spectroscopic study of the charge–transfer reaction of He+ with SiH4 at thermal energy. The SiH+(A 1Π–X 1Σ+) emission was observed in the 380–610 nm region. The nascent vibrational and rotational distributions of SiH+(A) have been determined. The vibrational distribution for 0≤v'≤3 was approximately exponential with an effective vibrational temperature of 820±60 K. The rotational temperature decreased from 600 K for v'=0 to 300 K for v'=3. These data indicated that only about 3% of the excess energy is released as internal energy of SiH+(A). From the emission rate constant, SiH+(A) represents about 25% of the total SiH+ ion in the He++SiH4 reaction.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.452666
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Rotational energy distribution of CO(c 3Π:v'=0) in the near-resonant Ar(3P2)+12CO and 13CO electronic energy transfer (1989)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 90 (1989), S. 5891-5892 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.456403
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Nascent rovibrational distribution of O+2(A 2Πu) produced by He(2 3S) Penning ionization of O2 (1988)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 89 (1988), S. 6753-6757 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The He(2 3S) Penning ionization of O2 to give O+2(A 2Πu) has been studied by observing the O+2(A 2Πu–X 2Πg) emission in beam and flowing afterglow apparatus. A comparison of beam and flowing afterglow data indicates that the nascent rovibrational distribution is lost in the flowing afterglow due to collisional relaxation. The nascent vibrational distribution of O+2(A 2Πu) shifts to lower vibrational levels in comparison with the Franck–Condon factors for vertical O2(X)→O+2(A) ionization. The rotational temperature decreases from 4200 K for v'=0 to 400 K for v'=13. Vibrational relaxation of O+2(A) accompanied by a significant rotational excitation is explained as a result of a short-range repulsive interaction [He–O+2(A)→He+O+2(A)] in the exit channel.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.455349
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Nascent rovibrational distributions of HCl+(A 2∑+) and HBr+(A 2∑+) produced from He(2 3S) Penning ionization of HCl and HBr (1987)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 87 (1987), S. 2695-2699 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: He(2 3S) Penning ionization of HCl and HBr leading to HCl+(A) and HBr+(A) has been investigated spectroscopically by using a low-pressure experimental apparatus coupled with a flowing afterglow source. The vibrational distribution of HCl+(A) agrees well with the result obtained by Penning ionization electron spectroscopy (PIES), which shows a Franck–Condon like distribution. In contrast, the vibrational distribution of HBr+(A) is more deexcited than the PIES one shifting to lower vibrational levels relative to Franck–Condon factors for ionization. These findings indicate that the collisional perturbation occurs only at the entrance channel for the He(2 3S)/HCl system, while at both entrance and exit ones for the He(2 3S)/HBr system. The rotational temperature of HCl+(A) decreases from 600±100 K for v′=0 to 300±100 K for v′=5, while that of HBr+(A) is 450±50 K for v′=0 and 400±50 K for v′=1.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.453108
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Formation of NO(A 2Σ+, C 2Πr, D 2Σ+) by the ion–ion neutralization reaction between NO+ and C6F6− at thermal energy (1995)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 102 (1995), S. 6013-6020 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The ion–ion neutralization reaction between NO+ (X 1Σ+:v‘=0) and C6F−6 has been spectroscopically studied in the flowing helium afterglow. In addition to the NO(A 2Σ+–X 2Πr) emission system, which has been found in the previous studies on the NO+/NO−2 and NO+/SF−6 reactions, the NO(C 2Πr–X 2Πr, D 2Σ+–X 2Πr) emission systems are observed in the NO+/C6F−6 reaction. The relative formation rates of NO(A), NO(C), and NO(D) are evaluated to be 1.0, 0.13±0.04, and 0.24±0.04, respectively. Only the v'=0 levels of NO(A,C,D) are formed, indicating that no energy is deposited into the vibration of NO(A,C,D). The rotational distributions of NO(A:v'=0), NO(C:v'=0), and NO(D:v'=0) are expressed by single Boltzmann rotational temperature of 500±50, 300±50, and 400±50 K, respectively. The average fractions of the total available energy deposited into rotation of NO(A), NO(C), and NO(D) are evaluated to be only 1.5±0.1%, 1.4±0.2%, and 1.9±0.2%, respectively. Most of all excess energy is expected to be partitioned into translation of the products. The observed vibrational and rotational distributions are less excited than statistical prior ones, indicating that the reaction dynamics is not governed by a simple statistical theory. The excitation mechanism of NO(A,C,D) in the NO+/C6F−6 reaction is compared with those in the NO+/NO−2 and NO+/SF−6 reactions, which give only the NO(A) state. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.469335
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Formation of NO(A 2Σ+) by the neutralization reaction between NO+ and SF−6 at thermal energy (1995)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 102 (1995), S. 2479-2486 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: An optical spectroscopic study has been made of the ion–ion neutralization reaction between NO+(X 1Σ+:v‘=0) and SF−6 in the flowing afterglow. Only the NO(A 2Σ+–X 2Πr) emission from v'=0 was excited, indicating that no energy is deposited into the vibration of NO(A). The rotational distribution of NO(A:v'=0) was expressed by a single Boltzmann rotational temperature of 600±50 K. The average fraction of the total available energy deposited into rotation of NO(A) was evaluated to be only 1.9%. Most of all excess energy was expected to be partitioned into translation of the products due to a strong mutual Coulombic attractive force between NO+ and SF−6. The observed vibrational and rotational distributions were less excited than statistical prior ones, indicating that the reaction dynamics is not governed by a simple statistical theory. The mechanism of the selective excitation of NO(A) in the ion–ion neutralization reaction was discussed. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.468677
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Rovibrational distributions of CH(A 2Δ,B 2Σ−) produced in energy-transfer reactions from Ar(3P2), Kr(3P2), and Xe(3P2) atoms to CH3 radical (1991)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 95 (1991), S. 7317-7326 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Energy-transfer reactions from Ar(3P2), Kr(3P2), and Xe(3P2) to CH3 radical have been studied by observing emission spectra from excited fragments in the flowing afterglow. CH3 radicals were generated by the F+CH4 reaction. The CH(A 2Δ–X 2Πr@B:v'=0−2) and CH(B 2Σ−–X 2Πr@B:v'=0) emission systems were observed in the Ar(3P2) reaction, while only CH(A–X:v'=0,1) emission system was found in the Kr(3P2) and Xe(3P2) reactions. The nascent rovibrational distributions of CH(A:v'=0–2) were N0@B:N1@B:N2 =100(T0 =3400±400 K):28±5(T1 =1700±400 K):4±1(T2 =700±300 K) in the Ar(3P2) reaction and 100(T0 =1000±250 K):〈5(T1 〈800 K):0 in the Kr(3P2) and Xe(3P2) reactions. The rotational distribution of CH(B:v'=0) in the Ar(3P2) reaction was reproduced by a single Boltzmann temperature of 2800±300 K. The average fractions of total available energies channeled into vibration and rotation of CH(A,B) were less than 15% for all cases, suggesting that most of the available energies was deposited as relative translational energy of products and/or rovibrational energy of H2. The observed rovibrational distributions of CH(A) were colder than those predicted from statistical theories including and excluding the conservation of total angular momentum. The best agreement between the observed and statistical distributions was obtained for the mechanism giving CH(A,B) in two-body dissociation steps by assuming that 78–92% of the total available energy is released as kinetic energy in the first step, Rg(3P2)+CH3→CH@B|3+Rg, then the rest remains in the precursor CH*3 state as an internal energy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.461409
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...