Library

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
    Photodissociation of 2-bromoethanol and 2-chloroethanol at 193 nm (1990)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 92 (1990), S. 2280-2286 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: 2-Bromoethanol and 2-chloroethanol were photodissociated in a molecular beam at 193 nm. Only one primary reaction channel was observed, elimination of the halogen atom, with an average translational energy release of 33 kcal/mol. In the case of 2-bromoethanol, some of the C2 H4 OH partner fragment survived and some underwent secondary dissociation to produce C2 H4 and OH. The surviving C2 H4 OH contained up to 43 kcal/mol of internal energy, far more than the expected C2 H4 -OH bond energy of ∼28 kcal/mol. The initial C–Br recoil occurs with a large exit impact parameter and leaves most of the internal energy in C2 H4 OH rotation, creating rotationally metastable fragments. The angular distributions of the secondary C2 H4 and OH products were strongly forward–backward peaked with respect to the primary (C2 H4 OH) velocity vector, consistent with the decay of a long-lived complex in which the total angular momentum is perpendicular to the velocity vector and mainly carried away as orbital angular momentum. This effect is analogous to that observed in the decay of similar long-lived complexes in crossed molecular beam experiments.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.458020
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    High resolution vacuum ultraviolet Stark measurement of the dipole moment of A˜ 1A‘ HCN (1992)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 96 (1992), S. 7209-7217 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: We report here the first measurement of the electric dipole moment of the A˜ 1A‘ state of HCN. Fluorescence excitation spectra of the A˜←X˜ 210K10 band were recorded using narrow band (〈0.1 cm−1) vacuum ultraviolet (VUV) produced by four-wave sum mixing in an improved strontium heat pipe. Accurate (±0.007 cm−1) term values for this band are reported. Surprisingly, we found that the asymmetry doubling of the upper state does not extrapolate to zero at J=0. We suggest that the most plausible explanation for this anomalous asymmetry doubling is a spin–orbit perturbation by a nearly degenerate level of the 1 3A' state. The a component of the dipole moment has been determined by the Stark splitting of the Q(1) transition as a function of electric field in a novel Stark cell capable of sustaining high electric fields (41 kV/cm) at pressures of 50 mTorr. The observed value of the dipole moment μa=0.99(10) D is in agreement with simple molecular orbital expectations and a semiempirical study.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.462425
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    High resolution vacuum ultraviolet fluorescence excitation spectrum and predissociation of A˜ 1A‘ HCN (1990)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 92 (1990), S. 3988-3989 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The A˜–X˜ fluorescence excitation spectrum of HCN has been recorded using 4-wave mixing in Sr vapor as a tunable vacuum ultraviolet source. The excitation spectra are notable for the high signal to noise ratio, resolution (FWHM ∼0.3 cm−1) of nearly all previously blended lines, and accuracy of wavelength calibration (±0.03 cm−1). Measured lifetimes for the first three bending levels of the A˜ state [τ(000)1=13±7 ns, τ(010)1=130±24 ns, and τ(020)1〈2 ns] qualitatively confirm the results of Hsu, Smith, and Wallace [Chem. Phys. Lett. 111, 219 (1984)]. Stern–Volmer fluorescence quenching studies reported here yield a best fit quenching constant for the A˜(000)1 rotational levels of Kq =73/μs⋅Torr, which is similar to the quenching constant of the A˜(010)1 level (Kq =24.3±0.4/μs⋅Torr).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.457809
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Dissociation of cyclohexene and 1,4-cyclohexadiene in a molecular beam (1989)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 91 (1989), S. 4118-4127 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Molecular-beam photofragmentation translational spectroscopy of cyclohexene and 1,4-cyclohexadiene was carried out using 193 nm and IR multiphoton excitation. At 193 nm, both the retro-Diels–Alder reaction of cyclohexene and H2 elimination from both molecules were observed in the ground electronic state, indicating the occurrence of internal conversion from the initially excited electronic states. The retro-Diels–Alder reaction is shown to be concerted up to an internal energy higher than 148 kcal/mol. Hydrogen-atom elimination was also observed for both molecules following 193 nm excitation. The H atom is eliminated from an excited state of cyclohexene and is assigned to be from a carbon adjacent to the double bond, with a corresponding C–H bond energy of 87±3 kcal/mol. It is shown that the peak of the translational energy distribution for concerted dissociation in the ground state is determined mainly by the dynamics of the potential-energy release along the reaction coordinate, and is not sensitive to either the amount of internal energy or the form of excitation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.456841
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    A concerted triple dissociation—the photochemistry of s-tetrazine (1989)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 90 (1989), S. 5527-5535 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The method of photofragment-translational spectroscopy was used in a molecular beam study of the photochemistry of s-tetrazine. Following 1B3u ←1Ag (S1←S0 excitation) or 1B2u ←1Ag (248 nm excitation), s-tetrazine reverts to the highly vibrationally excited ground electronic state through internal conversion, then decomposes into 2HCN+N2 via concerted triple dissociation. By analyzing the experimental data with a simple model, it was found that the potential energy surface along the reaction coordinate after the transition state is very repulsive, leading to most of the available energy, on average 73.9% in the case of S1 ←S0 excitation, going into translation. The asymptotic angles between N2 and HCN with respect to the center of mass of s-tetrazine were 117.2±0.5° and 114.4±0.5° for S1 ←S0 and 248 nm excitation, respectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.456405
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Optical Second-Harmonic Generation from Langmuir-Blodgett Films of an Asymmetrically Substituted Phthalocyanine (1995)
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 99 (1995), S. 6957-6960 
    Details
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/j100018a030
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Langmuir Film-Forming and Second Harmonic Generation Properties of Lanthanide Complexes (1995)
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 99 (1995), S. 14397-14402 
    Details
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/j100039a029
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Investigation of the A˜ 3E↔X˜ 3A2 system of methylnitrene radical by laser spectroscopy (1995)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 103 (1995), S. 4418-4426 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The vibrationally resolved laser-induced fluorescence spectra of the A˜ 3E↔X˜ 3A2 system of CH3N radical were obtained experimentally. The dispersed spectra at different vibrationally excited states confirm that the system studied belongs to the CH3N radical. From the vibrational progressions in the excitation spectrum, following vibrational frequencies of the A˜ 3E state were determined: ν1′=2943 cm−1, ν2′=1239 cm−1, ν3′=759 cm−1, and ν5′=1500 cm−1. In addition, the lifetimes of the A˜ 3E state at four vibrational states (ν3′=0, 3, 4, and 6) were measured, which are, respectively 292.8±1.2, 203.4±1.2, 188.2±0.5, and 157.2±0.5 ns at a total pressure of 1.7 Torr. Our experiments show that the A˜ 3E state is bound at least up to 4800 cm−1 and is relatively free from photochemistry. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.470682
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Production and photodissociation of trichloromethyl radicals in a molecular beam (1991)
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 95 (1991), S. 2799-2802 
    Details
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/j100160a031
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Numerical quantum propagation with time-dependent Hamiltonian (1996)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 105 (1996), S. 9536-9545 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: A numerical method was proposed to propagate the quantum system with a time-dependent Hamiltonian. The propagator is composed of the time-independent-Hamiltonian-type multisplit forms, which becomes possible by realizing that the evolution operator has a close link with the time-shift operator. The present algorithm can achieve a high order of accuracy through the recurrence of multisplit forms with predetermined coefficients, and it has the advantage that only the Hamiltonian itself at different time instants is involved, while other currently available schemes need to perform either a time integration or a time differential of the Hamiltonian. This essential difference has made our proposal highly competitive. A one-dimensional model system is considered to verify the accuracy and efficiency of the numerical scheme. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.472786
    Library Location Call Number Volume/Issue/Year 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...