The Experts below are selected from a list of 54 Experts worldwide ranked by ideXlab platform

Sandra Brünken - One of the best experts on this subject based on the ideXlab platform.

  • laboratory detection of thiocyanic Acid hscn
    The Astrophysical Journal, 2009
    Co-Authors: Zhenhong Yu, C A Gottlieb, Sandra Brünken, M C Mccarthy, Patrick Thaddeus
    Abstract:

    The rotational spectrum of thiocyanic Acid HSCN, a highly polar isomer of the well-known astronomical molecule Isothiocyanic Acid HNCS, has been measured in two radio bands: in the centimeter-wave band by Fourier transform microwave spectroscopy in a molecular beam, and in the millimeter-wave band by long-path absorption spectroscopy in a low-pressure glow discharge. Twelve spectroscopic constants were derived from more than 60 a-type rotational transitions between 11 and 346 GHz with J up to 30 and Ka ≤ 6, including seven centimeter-wave transitions with resolved hyperfine structure. With these constants the rotational spectrum in the Ka = 0 and Ka = 1 ladders—those most likely to be observed in space—can now be calculated up to 400 GHz with formal uncertainties of less than 0.2 km s–1 in equivalent radial velocity. Thiocyanic Acid was recently identified in Sgr B2 by Halfen et al. following the laboratory measurements, and there is possible evidence for it in cold dark clouds, with the implication that HSCN may be detectable in many galactic sources.

  • detection of a new interstellar molecule thiocyanic Acid hscn
    The Astrophysical Journal, 2009
    Co-Authors: D T Halfen, C A Gottlieb, Lucy M Ziurys, Sandra Brünken, M C Mccarthy, Patrick Thaddeus
    Abstract:

    A new interstellar molecule, HSCN (thiocyanic Acid), an energetic isomer of the well-known species HNCS, has been detected toward Sgr B2(N) with the Arizona Radio Observatory 12 m telescope. Eight rotational transitions in the Ka = 0 ladder were observed in the 2 mm and 3 mm bands. Five consecutive transitions in the 3 mm band are unblended, but three in the 2 mm band are partially masked by lines of other molecules. The peak intensity of all eight transitions are well described by a rotational temperature that is in very good agreement with that of many other molecules in this source. The line width and radial velocity of HSCN match closely with those of the ground state isomer HNCS (Isothiocyanic Acid), HNCO (isocyanic Acid), and HOCN (cyanic Acid); preliminary maps indicate that all four molecules are similarly distributed in Sgr B2. Although HSCN is calculated to lie over 3000 K higher in energy than HNCS, its column density of 1.3 × 1013 cm–2 in Sgr B2(N) is only three times lower than that of HNCS. The fractional abundances of HSCN and HNCS relative to H2 are 4.5 × 10–12 and 1.1 × 10–11. By analogy with the isomeric pair HCN and HNC, these two sulfur-bearing isomers are plausibly formed from a common cation precursor.

Patrick Thaddeus - One of the best experts on this subject based on the ideXlab platform.

  • laboratory detection of thiocyanic Acid hscn
    The Astrophysical Journal, 2009
    Co-Authors: Zhenhong Yu, C A Gottlieb, Sandra Brünken, M C Mccarthy, Patrick Thaddeus
    Abstract:

    The rotational spectrum of thiocyanic Acid HSCN, a highly polar isomer of the well-known astronomical molecule Isothiocyanic Acid HNCS, has been measured in two radio bands: in the centimeter-wave band by Fourier transform microwave spectroscopy in a molecular beam, and in the millimeter-wave band by long-path absorption spectroscopy in a low-pressure glow discharge. Twelve spectroscopic constants were derived from more than 60 a-type rotational transitions between 11 and 346 GHz with J up to 30 and Ka ≤ 6, including seven centimeter-wave transitions with resolved hyperfine structure. With these constants the rotational spectrum in the Ka = 0 and Ka = 1 ladders—those most likely to be observed in space—can now be calculated up to 400 GHz with formal uncertainties of less than 0.2 km s–1 in equivalent radial velocity. Thiocyanic Acid was recently identified in Sgr B2 by Halfen et al. following the laboratory measurements, and there is possible evidence for it in cold dark clouds, with the implication that HSCN may be detectable in many galactic sources.

  • detection of a new interstellar molecule thiocyanic Acid hscn
    The Astrophysical Journal, 2009
    Co-Authors: D T Halfen, C A Gottlieb, Lucy M Ziurys, Sandra Brünken, M C Mccarthy, Patrick Thaddeus
    Abstract:

    A new interstellar molecule, HSCN (thiocyanic Acid), an energetic isomer of the well-known species HNCS, has been detected toward Sgr B2(N) with the Arizona Radio Observatory 12 m telescope. Eight rotational transitions in the Ka = 0 ladder were observed in the 2 mm and 3 mm bands. Five consecutive transitions in the 3 mm band are unblended, but three in the 2 mm band are partially masked by lines of other molecules. The peak intensity of all eight transitions are well described by a rotational temperature that is in very good agreement with that of many other molecules in this source. The line width and radial velocity of HSCN match closely with those of the ground state isomer HNCS (Isothiocyanic Acid), HNCO (isocyanic Acid), and HOCN (cyanic Acid); preliminary maps indicate that all four molecules are similarly distributed in Sgr B2. Although HSCN is calculated to lie over 3000 K higher in energy than HNCS, its column density of 1.3 × 1013 cm–2 in Sgr B2(N) is only three times lower than that of HNCS. The fractional abundances of HSCN and HNCS relative to H2 are 4.5 × 10–12 and 1.1 × 10–11. By analogy with the isomeric pair HCN and HNC, these two sulfur-bearing isomers are plausibly formed from a common cation precursor.

C A Gottlieb - One of the best experts on this subject based on the ideXlab platform.

  • laboratory detection of thiocyanic Acid hscn
    The Astrophysical Journal, 2009
    Co-Authors: Zhenhong Yu, C A Gottlieb, Sandra Brünken, M C Mccarthy, Patrick Thaddeus
    Abstract:

    The rotational spectrum of thiocyanic Acid HSCN, a highly polar isomer of the well-known astronomical molecule Isothiocyanic Acid HNCS, has been measured in two radio bands: in the centimeter-wave band by Fourier transform microwave spectroscopy in a molecular beam, and in the millimeter-wave band by long-path absorption spectroscopy in a low-pressure glow discharge. Twelve spectroscopic constants were derived from more than 60 a-type rotational transitions between 11 and 346 GHz with J up to 30 and Ka ≤ 6, including seven centimeter-wave transitions with resolved hyperfine structure. With these constants the rotational spectrum in the Ka = 0 and Ka = 1 ladders—those most likely to be observed in space—can now be calculated up to 400 GHz with formal uncertainties of less than 0.2 km s–1 in equivalent radial velocity. Thiocyanic Acid was recently identified in Sgr B2 by Halfen et al. following the laboratory measurements, and there is possible evidence for it in cold dark clouds, with the implication that HSCN may be detectable in many galactic sources.

  • detection of a new interstellar molecule thiocyanic Acid hscn
    The Astrophysical Journal, 2009
    Co-Authors: D T Halfen, C A Gottlieb, Lucy M Ziurys, Sandra Brünken, M C Mccarthy, Patrick Thaddeus
    Abstract:

    A new interstellar molecule, HSCN (thiocyanic Acid), an energetic isomer of the well-known species HNCS, has been detected toward Sgr B2(N) with the Arizona Radio Observatory 12 m telescope. Eight rotational transitions in the Ka = 0 ladder were observed in the 2 mm and 3 mm bands. Five consecutive transitions in the 3 mm band are unblended, but three in the 2 mm band are partially masked by lines of other molecules. The peak intensity of all eight transitions are well described by a rotational temperature that is in very good agreement with that of many other molecules in this source. The line width and radial velocity of HSCN match closely with those of the ground state isomer HNCS (Isothiocyanic Acid), HNCO (isocyanic Acid), and HOCN (cyanic Acid); preliminary maps indicate that all four molecules are similarly distributed in Sgr B2. Although HSCN is calculated to lie over 3000 K higher in energy than HNCS, its column density of 1.3 × 1013 cm–2 in Sgr B2(N) is only three times lower than that of HNCS. The fractional abundances of HSCN and HNCS relative to H2 are 4.5 × 10–12 and 1.1 × 10–11. By analogy with the isomeric pair HCN and HNC, these two sulfur-bearing isomers are plausibly formed from a common cation precursor.

M C Mccarthy - One of the best experts on this subject based on the ideXlab platform.

  • laboratory detection of thiocyanic Acid hscn
    The Astrophysical Journal, 2009
    Co-Authors: Zhenhong Yu, C A Gottlieb, Sandra Brünken, M C Mccarthy, Patrick Thaddeus
    Abstract:

    The rotational spectrum of thiocyanic Acid HSCN, a highly polar isomer of the well-known astronomical molecule Isothiocyanic Acid HNCS, has been measured in two radio bands: in the centimeter-wave band by Fourier transform microwave spectroscopy in a molecular beam, and in the millimeter-wave band by long-path absorption spectroscopy in a low-pressure glow discharge. Twelve spectroscopic constants were derived from more than 60 a-type rotational transitions between 11 and 346 GHz with J up to 30 and Ka ≤ 6, including seven centimeter-wave transitions with resolved hyperfine structure. With these constants the rotational spectrum in the Ka = 0 and Ka = 1 ladders—those most likely to be observed in space—can now be calculated up to 400 GHz with formal uncertainties of less than 0.2 km s–1 in equivalent radial velocity. Thiocyanic Acid was recently identified in Sgr B2 by Halfen et al. following the laboratory measurements, and there is possible evidence for it in cold dark clouds, with the implication that HSCN may be detectable in many galactic sources.

  • detection of a new interstellar molecule thiocyanic Acid hscn
    The Astrophysical Journal, 2009
    Co-Authors: D T Halfen, C A Gottlieb, Lucy M Ziurys, Sandra Brünken, M C Mccarthy, Patrick Thaddeus
    Abstract:

    A new interstellar molecule, HSCN (thiocyanic Acid), an energetic isomer of the well-known species HNCS, has been detected toward Sgr B2(N) with the Arizona Radio Observatory 12 m telescope. Eight rotational transitions in the Ka = 0 ladder were observed in the 2 mm and 3 mm bands. Five consecutive transitions in the 3 mm band are unblended, but three in the 2 mm band are partially masked by lines of other molecules. The peak intensity of all eight transitions are well described by a rotational temperature that is in very good agreement with that of many other molecules in this source. The line width and radial velocity of HSCN match closely with those of the ground state isomer HNCS (Isothiocyanic Acid), HNCO (isocyanic Acid), and HOCN (cyanic Acid); preliminary maps indicate that all four molecules are similarly distributed in Sgr B2. Although HSCN is calculated to lie over 3000 K higher in energy than HNCS, its column density of 1.3 × 1013 cm–2 in Sgr B2(N) is only three times lower than that of HNCS. The fractional abundances of HSCN and HNCS relative to H2 are 4.5 × 10–12 and 1.1 × 10–11. By analogy with the isomeric pair HCN and HNC, these two sulfur-bearing isomers are plausibly formed from a common cation precursor.

Pokol György - One of the best experts on this subject based on the ideXlab platform.

  • Comparative evolved gas analyses on thermal degradation of thiourea by coupled TG-FTIR and TG/DTA-MS instruments
    'Springer Science and Business Media LLC', 2007
    Co-Authors: Madarász János, Pokol György
    Abstract:

    Identification and monitoring of gaseous species released during thermal decomposition of pure thiourea, (NH2)(2)C=S in argon, helium and air atmosphere have been carried out by both online coupled TG-FTIR and simultaneous TG/DTA-MS apparatuses manufactured by TA Instruments (USA). In both inert atmospheres and air between 182 and 240 degrees C the main gaseous products of thiourea are ammonia (NH3) and carbon disulfide (CS2), whilst in flowing air sulphur dioxide (SO2) and carbonyl sulphide (COS) as gas phase oxidation products of CS2, and in addition hydrogen cyanide (HCN) also occur, which are detected by both FTIR spectroscopic and mass spectrometric EGA methods. Some evolution of Isothiocyanic Acid (HNCS) and cyanamide (NH2CN) vapours have also observed mainly by EGA-FTIR, and largely depending on the experimental conditions. HNCS is hardly identified by mass spectrometry. Any evolution of H2S has not been detected at any stage of thiourea degradation by either of the two methods. The exothermic heat effect of gas phase oxidation process of CS2 partially compensates the endothermicity of the corresponding degradation step producing CS2

  • Evolved gas analysis of dichlorobis(thiourea)zinc(II) by coupled TG-FTIR and TG/DTA-MS techniques
    'Akademiai Kiado Zrt.', 2004
    Co-Authors: Madarász János, Krunks M., Niinisto L., Pokol György
    Abstract:

    Identification and monitoring of gaseous species released during thermal decomposition of the title compound 1, Zn(tu)(2)Cl-2, (tu=thiourea, (NH2)(2)C=S) have been carried out in flowing air atmosphere up to 800degreesC by both online coupled TG-EGA-FTIR and simultaneous TG/DTA-EGA-MS. The first gaseous products of 1, between 200 and 240degreesC, are carbon disulfide (CS2) and ammonia (NH3). At 240degreesC, an exothermic oxidation of CS2 vapors occurs resulting in a sudden release of sulphur dioxide (SO2) and carbonyl sulphide (COS). An intense evolution of hydrogen cyanide (HCN) and beginning of the evolution of cyanamide (H2NCN) and Isothiocyanic Acid (HNCS) are also observed just above 240degreesC. Probably because of condensation and/or polymerization of cyanamide vapors on the windows and mirrors of the FTIR gas cell optics, some strange baseline shape changes are also occurring above 330degreesC. Above 500degreesC the oxidation process of organic residues appears to accelerate which is indicated by the increasing concentration of CO2, while above 600degreesC zinc sulfide starts to oxidize resulting in the evolution of SO2. All species identified by FTIR gas cell were also confirmed by mass spectrometry, except for HNCS

  • Comparative online coupled TG-FTIR and TG/DTA-MS analyses of the evolved gases from thiourea complexes of SnCl2.
    'Elsevier BV', 2004
    Co-Authors: Madarász János, Bombicz P., Okuya M., Kaneko S., Pokol György
    Abstract:

    Identification and monitoring of gaseous species released during thermal decomposition of title compound 1, Sn-2(tu)(5)Cl(4)(.)2H(2)O (tu stands for thiourea (NH2)(2)C=S)) in flowing air atmosphere have been carried out up to 600 degreesC by both online coupled TG-EGA-FTIR and simultaneous TG/DTA-EGA-MS apparatuses. The first gaseous products of the dehydrated 1, evolved around 190 degreesC, are carbonyl sulphide (COS), carbon disulfide (CS2), and cyanamide (NH2CN). At 240 degreesC Isothiocyanic Acid, HNCS becomes the main product, accompanied by CS2, ammonia (NH3) a small amount of hydrogen cyanide (HCN) and traces of hydrogen chloride (HCI), according to EGA-FTIR spectroscopic analysis. At 250 degreesC formation of sulphur dioxide (SO2) has been observed by EGA-mass spectrometry. SO2 as air oxidation product of tin sulphides, formed in the previous stages, occurs also around 430 degreesC, while gaseous oxidation products of the organic residues, such as CO2 and NH2CN are released at 515 degreesC. Both oxidation processes are accompanied by an exothermic heat effect. All species identified by FTIR gas cell are also confirmed by mass spectrometry, except HNCS. (C) 2004 Elsevier B.V. All rights reserved

  • Online coupled TG-FTIR and TG/DTA-MS analyses of the evolved gases from dichloro(thiourea) tin(II)
    'Elsevier BV', 2004
    Co-Authors: Madarász János, Bombicz P., Okuya M., Kaneko S., Pokol György
    Abstract:

    Identification and monitoring of gaseous species released during thermal decomposition of title compound 1, dichloro(thiourea) tin(II), Sn(tU)Cl-2, [thiourea (tu), (NH2)(2)C=S] in flowing air atmosphere have been carried out by both online coupled TG-FTIR and simultaneous TG/DTA - MS evolved gas -analysis (EGA) instruments. The first gaseous products of 1, evolved from 170 degreesC, are cyanamide (NH2CN), carbonyl sulphide (COS), carbon disulfide (CS2) and water (H2O). At 240 degreesC Isothiocyanic Acid (HNCS) becomes the main product, accompanied by CS2, hydrogen cyanide (HCN) and traces of hydrogen chloride (HCI) according to EGA-FTIR analysis. Ammonia (NH3) occurs first only above 250 degreesC, while sulfur dioxide (SO2) formation is not observed till 400 degreesC. Air oxidation products of tin sulphides and organic residues, such as SO2, carbon dioxide (CO2) and NH2CN, occur suddenly at 425 degreesC together with a very sharp exothermic heat effect. All species identified by FTIR gas cells are confirmed by mass spectrometry, except HNCS. Evolution of H2S has not been observed at any stage of the degradation of 1 by either of the EGA methods. (C) 2004 Elsevier B.V. All rights reserved