Library

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
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 91 (1989), S. 6613-6631 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: High-resolution near-infrared spectra are reported for all of the O–H stretch vibrational bands of the water dimer. The four O–H vibrations are characterized as essentially independent proton-donor or proton-acceptor motions. In addition to the rotational and vibrational information contained in these spectra, details are obtained concerning the internal tunneling dynamics in both the ground and excited vibrational states. These results show that for tunneling motions which involve the interchange of the proton donor and acceptor molecules, the associated frequencies decrease substantially due to vibrational excitation. The predissociation lifetimes for the various states of the dimer are determined from linewidth measurements. These results clearly show that the predissociation dynamics is strongly dependent on the tunneling states, as well as the Ka quantum number, indicating that the internal tunneling dynamics plays an important role in determining the dissociation rate in this complex.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 90 (1989), S. 1478-1483 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The optothermal molecular beam technique has been used to record the near infrared spectrum of the acetylene–HF binary complex associated with the ν7 vibrational mode (asymmetric C–H stretch). A fit to this perpendicular band spectrum gives accurate rotational constants for both the ground and excited vibrational states, as well as the vibrational origin, namely A‘=1.192 60(5) cm−1 , B‘=0.157 34(1) cm−1 , C‘=0.138 10(1) cm−1 , A'=1.186 90(5) cm−1 , B'=0.157 34(1) cm−1 , C'=0.138 08(1) cm−1, and ν0 =3276.2889(30) cm−1 . From the homogeneous linewidths of the observed transitions the lifetime of the excited vibrational state has been determined to be 3.6 ns. When compared with the lifetime determined previously for the ν1 mode (0.8 ns) and the data obtained previously for several other systems, it is clear that vibrational relaxation in this molecule is mode specific. A discussion is given concerning the nature of this relaxation process.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 88 (1988), S. 2185-2195 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Sub-Doppler infrared spectra of two Fermi resonance coupled bands of carbon dioxide dimer have been obtained at 3611.5 and 3713.9 cm−1 using an optothermal molecular beam color-center laser spectrometer. The band origins for the complexes are red shifted by approximately 1 cm−1 from the corresponding ν1+ν3/2ν02+ν3 CO2 bands. The higher frequency band is perturbed while the lower frequency band appears free of extraneous perturbations as determined from a precision fit to a Watson asymmetric rotor Hamiltonian. This fit and the observed nuclear spin statistical weights reveal that the complex is planar with C2h symmetry. The C--C separation and C--C–O angle are determined to be 3.599(7) A(ring) and 58.2(8)°, respectively. The nearest neighbor O--C distance is 3.14 A(ring) which is the same as that found in the crystal. From the centrifugal distortion analysis the weak bond stretching and symmetric bending frequencies are estimated to be 32(2) and 90(1) cm−1. No interconversion tunneling is observed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 89 (1988), S. 5408-5416 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The opto-thermal detection method has been used to obtain rotationally resolved infrared spectra for both (14N14N16O)2 and (15N14N16O)2. The vibrational band observed in each case correlates with the ν1+ν3 band of the N2O monomer. A large number of A- and B-type transitions have been assigned and fit for both species yielding accurate molecular constants for both the ground and excited vibrational states. From intensity alternations associated with nuclear spin statistics and the small inertia defect [Δ‘=0.611 amu A(ring)2 for (14N14N16O)2], it is clear that the nitrous oxide dimer has a slipped parallel geometry which possesses a center of symmetry. Isotopic substitution shows that of the two such structures, only the one having the oxygen atoms close to one another is experimentally observed. The structural constants are determined to be RNN=3.493(4) A(ring) and θNNO=59.2(5)°.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 96 (1992), S. 4140-4143 
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 92 (1988), S. 46-50 
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 88 (1988), S. 8008-8009 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 86 (1987), S. 1098-1103 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The ν1 infrared spectrum of N2–HF has been observed at sub-Doppler resolution using an infrared laser–molecular beam apparatus which is based on the optothermal detection method. This spectrum has been used to obtain the following molecular constants: B1=0.107 19±0.0001 cm−1 and ν0=3918.2397±0.005 cm−1. In addition, the Stark spectrum of the R1 transition was recorded in order to determine the ground (μ0=1.991±0.008 D) and excited vibrational (μ1=2.106±0.008 D) state dipole moments of the complex. Spectra recorded at the highest resolution clearly show homogeneous broadening of the individual rotational transitions giving a predissociation lifetime of 44±10 ns.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 86 (1987), S. 4341-4346 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: An F-center laser–molecular beam spectrometer has been used to obtain a sub-Doppler resolution infrared spectrum of the carbon dioxide dimer. The vibrational mode investigated in this study corresponds to the ν1+ν3 combination mode of the monomer located at 3716 cm−1. A qualitative assignment of the spectrum shows unambiguously that the equilibrium structure of the dimer is the slipped parallel, rather than the T-shaped, geometry. The observed spectrum cannot be fit to within experimental error using conventional asymmetric rotor formalism. This may be due to a number of factors such as Fermi resonance between the upper state levels of the band and nearby levels of the dimer, such as seen in the monomer, or it could arise from tunneling effects arising from the two large amplitude motions in the dimer.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 85 (1986), S. 3338-3341 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: A computer controlled F-center laser has been used, in conjunction with a molecular beam apparatus employing optothermal detection, to obtain an accurate measurement of the vibrational predissociation lifetime of the HF dimer following ν1 vibrational excitation. The lifetime obtained in this study is 24±2 ns. This is to be compared with a lifetime for ν2 excitation of 1.0±0.1 ns.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...