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
    The ultraviolet photolysis of acetyl and propionyl radicals studied by infrared emission spectroscopy (1997)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 106 (1997), S. 5943-5946 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The photodissociation of acetyl and propionyl radicals at 248 and 266 nm has been studied by time-resolved Fourier transform infrared spectroscopy. A vibrationally excited product CO(v≤8) was observed in the emission spectra. The vibrational temperatures of the nascent CO products were about 7400 K for the acetyl radical and 6930 K for the propionyl radical. The vibrational energy partitioning of the CO fragments fits a soft impulsive model. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.473259
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    The formation, photodissociation, and bond structure of cobalt–sulfur cluster ions (1994)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 101 (1994), S. 9528-9533 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The formation and photodissociation of cobalt–sulfur cluster ions (ConS+m) produced by laser ablation on a tablet of well-mixed cobalt and sulfur powder were studied with a home-built tandem time-of-flight (TOF) mass spectrometer. In the mass spectrum, there are many intense peaks of more stable cluster ions ConS+m signified as follows: n=2–5,7, m=n−1; n=6,8–11, m=n−2; n=12–13, m=n−3; n=14–16, m=n−4. The photolysis of the mass-selected cluster ions was performed with a 248 nm excimer laser. The dissociation patterns support the above composition results. Previous theories about clusters do not explain the experimental results. A relationship between the electron number and orbital number of more stable clusters was recognized. Ab initio calculations were performed on two small cluster ions to determine stable geometries. © 1994 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.467984
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    The ultrafast intramolecular dynamics of phthalocyanine and porphyrin derivatives (1996)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 105 (1996), S. 5377-5379 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The internal conversion and intramolecular vibrational relaxation processes of nitro-tri-tert-butylphthalocyanine, tetra-phenylporphyrin (TPP), and tetra-tert-butylphthalocyanine (BuPc) in chloroform solution were investigated with an ultrafast time-resolved fluorescence depletion method. A regular fluorescence depletion was observed, indicating that the vibrational relaxation in the S1 state takes a few hundred femtoseconds to several picoseconds. For TPP and BuPc, an additional sharp dip superposes on the regular depletion. It is explained by an ultrafast internal conversion process from the S2 state to the S1 state with a time of a few tens of femtoseconds. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.472378
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    The gaseous reaction of vinyl radical with oxygen (2001)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 115 (2001), S. 1742-1746 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The gaseous reaction of vinyl radical with oxygen has been experimentally investigated. C2H3 radical was produced by laser photolysis of C2H3Br at 248 nm. The vibrationally excited products of the reaction were detected by time-resolved Fourier transform infrared emission spectroscopy. H2CO(ν1), HCO(ν1,ν3), and CO2(ν3) are ascertained as the main emitters. The most favorable product channel is HCO and H2CO. The reaction channel leading to CO2+CH3 has been found for the first time. The minor reactions leading to C2H2+HO2, C2H3O+O, and C2H2O2+H may also occur. A secondary reaction product of CO is observed, which is generated from the primary reaction product HCO. Combining theoretical analysis with the present experimental results, the reaction pathways are clarified. The results are of importance for understanding the combustion processes of hydrocarbon. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1382814
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    The production and photodissociation of iron–sulfur cluster ions (1993)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 99 (1993), S. 1765-1770 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Iron–sulfur cluster ions FenSm+ (n=1–13, m=1–13) were produced by direct laser ablation on a solid sample containing a mixture of iron and sulfur powder. UV photodissociation of the cluster ions was studied with a tandem time-of-flight mass spectrometer. It was found that all the cluster ions with compositions of m=n, m=n−1, or m=n+5 were relatively more abundant, indicating that they were stable. The photodissociation results of the FenSm+ ions showed that, for parent ions with n(very-much-less-than)m, the main channels were sequential losses of neutral S atoms until n∼m, while for parent ions with n∼m, the main product ions had compositions of smaller m=n or m=n−1. From these experimental results, it is proposed that the FenSn+ cluster ions might have structures similar to those of the FenS*n cores in iron–sulfur proteins, while the FenSm+ (m(approximately-greater-than)n) cluster ions could be considered to have structures with the FenSn+ cores surrounded by some peripheral S atoms.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.465293
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Aluminum–sulfur cluster ions: Formation and photolysis (1994)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 101 (1994), S. 1219-1224 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Aluminum–sulfur cluster ions were obtained by direct laser ablation (248 nm, ≥10 MW/cm2) and analyzed with a tandem time-of-flight mass spectrometer. The regular peaks of cluster ions having composition of AlS+(Al2S3)n (n=1,2,3,...,31) were shown on the first time-of-flight mass spectrum (TOF-MS). The cluster ions of a certain mass number (m/e) could be selected and photolyzed by an ArF laser (193 nm, 1 MW/cm2). The product ions were analyzed by a second TOF-MS. It was found that the cluster ions lost (Al2S3)x (x=1, 3, or 4) and became smaller cluster ions of the same stable formula AlS+(Al2S3)n−x. Cagelike structures were proposed to be possible for these stable cluster ions. Semiempirical and ab initio quantum chemical calculations have also been performed for some of the clusters.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.467814
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Reaction dynamics of electronically state-specific CH2 with NO (2000)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 113 (2000), S. 1885-1890 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: With time-resolved Fourier transform infrared emission spectroscopy and DFT B3LYP quantum calculation, the reaction dynamics of CH2(X˜ 3B1) and CH2(a˜ 1A1) with NO have been investigated. It is found that both 3CH2+NO and 1CH2+NO reactions follow the same reaction pathways and produce same products arising from the same elementary channels. The primary products of vibrationally excited CO(v), HCO(v1), HOCN(v2), OH(v), and NH2(v3) were detected for the first time and four reaction channels have thus been identified. Theoretically, a doublet potential energy surface is characterized. On the potential energy surfaces, both the 3CH2+NO and 1CH2+NO systems reach a crucial intermediate OCHNH via a CNO ring-closure and ring-opening process. From this intermediate, the four reaction pathways proceed: C–N bond rupture in OCHNH simply leads to NH+HCO; OCHNH rearranges either to H2NCO producing CO+NH2, or to HOCHN generating HOCN+H and HCN+OH. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.481992
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Photodissociation of formic acid (2000)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 113 (2000), S. 1891-1897 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The photodissociation of formic acid has been studied experimentally and theoretically. Ab initio calculations were performed to study the dissociative profiles of five reaction channels on the S0, S1, and T1 potential energy surfaces. The vibrationally excited nascent products were detected using a time-resolved Fourier transform infrared spectrometer after laser photolysis at 248 or 193 nm. In the 248 nm photolysis, the HCOOH molecule was first excited to the S1 state, but it was found that the dissociation takes place on the S0 surface after internal conversion. The products of the vibrationally excited CO, CO2(v3) and H2O(v1) were detected. During the dissociation process the vibrationally energized molecule is geometrically memorized and dynamically controlled, with the yield preference of CO and H2O over that of CO2 and H2. The ratio of CO(v≥1)/CO2(v≥1) is estimated as 〈7.5. Vibrationally excited CO (v) and CO2(v3) are also found in the 193 nm photolysis but the CO/CO2 ratio increases to 11. Most of the dissociation is thought to occur on the S0 state. At this wavelength another dissociation channel which produces OH and HCO radicals on S1 surface has been identified. The dissociation is unlikely to occur on the T1 surface, as the energy barriers are fairly high. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.482076
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    The formation and photolysis of tantalum sulfide cluster ions (1993)
    Springer
    The European physical journal 26 (1993), S. 246-248 
    Details
    ISSN: 1434-6079
    Keywords: 82.30.N ; 36.40 ; 82.50.F
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Tantalum sulfide cluster ions were produced by direct laser ablation, and were studied with a tandem time-of-flight mass spectrometer. The main dissociation channel of the UV-photolysis (248 nm) of tantalum sulfide cluster ions is sequent S2 loss. Structures with Ta3S4 and Ta4S6 as frameworks were suggested for the large tantalum sulfide cluster ions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01425679
    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...