The broadband rotational spectrum of fully deuterated acetaldehyde (CD 3 CDO) in a CW supersonic expansion

Abstract The broadband pure rotational spectra of CD 3 CDO, 13 CD 3 CDO, CD 3 13 CDO, and CD 3 CD 18 O have been recorded using a BrightSpec W-Band (75–110 GHz) chirped-pulse Fourier transform millimeter wave (CP-FTmmW) spectrometer. The sample was enriched with deuterium, whereas the 13 C and 18 O isotopologues were observed in natural abundance (with respect to the enriched fully deuterated parent containing 12 C and 16 O). The analysis of the spectra is described and the derived molecular constants are compared to those of known acetaldehyde isotopologues. Furthermore, we have demonstrated the ability to record rotational spectra in a steady-state “CW” supersonic expansion with a duty cycle of 80%. The advantages and limitations of the segmented chirp spectrometer coupled with a CW molecular source as well as design of the vacuum and pumping system are discussed.

[1]  Blanco,et al.  The Ground and First Torsional States of CD(3)CHO. , 1999, Journal of Molecular Spectroscopy.

[2]  P. Friberg,et al.  The detection of acetaldehyde in cold dust clouds. , 1985, The Astrophysical journal.

[3]  C. Lin,et al.  Calculation of Energy Levels for Internal Torsion and Over‐All Rotation. II. CH3CHO Type Molecules; Acetaldehyde Spectra , 1957 .

[4]  L. Coudert,et al.  The microwave and far infrared spectra of acetaldehyde-d1 , 2010 .

[5]  G. B. Park,et al.  Perspective: The first ten years of broadband chirped pulse Fourier transform microwave spectroscopy. , 2016, The Journal of chemical physics.

[6]  J. T. Hougen,et al.  Selection Rules and Intensity Calculations for a Cs Asymmetric Top Molecule Containing a Methyl Group Internal Rotor , 1994 .

[7]  P. Turner,et al.  Centrifugal distortion and internal rotation in the microwave spectrum of acetaldehyde , 1976 .

[8]  B. McCall,et al.  Note: A modular and robust continuous supersonic expansion discharge source. , 2010, The Review of scientific instruments.

[9]  J. Toennies,et al.  Theoretical studies of highly expanded free jets: Influence of quantum effects and a realistic intermolecular potential , 1977 .

[10]  Bryan M. Wong,et al.  A new approach toward transition state spectroscopy. , 2013, Faraday discussions.

[11]  R. Byer,et al.  Very-high-resolution CARS spectroscopy in a molecular beam (A) , 1979 .

[12]  L. Ziurys,et al.  The spectrum of Orion-KL at 2 millimeters (150-160 GHz). , 1993, The Astrophysical journal. Supplement series.

[13]  Brooks H. Pate,et al.  A Ka-band chirped-pulse Fourier transform microwave spectrometer , 2010 .

[14]  C. Lin,et al.  Microwave Spectrum and Internal Barrier of Acetaldehyde , 1956 .

[15]  Gordon G. Brown,et al.  A broadband Fourier transform microwave spectrometer based on chirped pulse excitation. , 2008, The Review of scientific instruments.

[16]  S. Klippenstein,et al.  Decomposition of acetaldehyde: Experiment and detailed theory , 2007 .

[17]  W. Irvine,et al.  Survey Observations of c-C2H4O and CH3CHO toward Massive Star-forming Regions , 2001 .

[18]  Gordon G. Brown,et al.  Conformational isomerization kinetics of pent-1-en-4-yne with 3,330 cm−1 of internal energy measured by dynamic rotational spectroscopy , 2008, Proceedings of the National Academy of Sciences.

[19]  J. Daily,et al.  The products of the thermal decomposition of CH3CHO. , 2011, The Journal of chemical physics.

[20]  Melanie Schnell,et al.  Broadband Rotational Spectroscopy for Molecular Structure and Dynamics Studies , 2012 .

[21]  José Cernicharo,et al.  Waveguide CP-FTMW and millimeter wave spectra of s-cis- and s-trans-acrylic acid , 2015 .

[22]  U. Even,et al.  Generation and propagation of intense supersonic beams. , 2011, The journal of physical chemistry. A.

[23]  L. Coudert,et al.  Internal rotation and hyperfine coupling interaction in deuterated acetaldehyde , 2006 .

[24]  B. Turner.  A Molecular Line Survey of Sagittarius B2 and Orion--KL from 70 to 115 GHz. II. Analysis of the Data , 1991 .

[25]  L. Margulès,et al.  Millimeter and submillimeter wave spectra of mono- 13 C-acetaldehydes , 2015 .

[26]  W. Irvine,et al.  Abundances of ethylene oxide and acetaldehyde in hot molecular cloud cores. , 1998, Astronomy and astrophysics.

[27]  P. R. Westmoreland,et al.  Biofuel combustion chemistry: from ethanol to biodiesel. , 2010, Angewandte Chemie.

[28]  H. Dreizler,et al.  The Microwave Spectrum of trans-2,3-Dimethyloxirane in Torsional Excited States , 1996 .

[29]  D. W. Knight,et al.  Internal rotation in nitrosomethane and acetaldehyde: incremental effect of deuterium substitution on the potential for methyl torsion , 1988 .

[30]  R. Byer,et al.  High-resolution continuous-wave coherent anti-Stokes Raman spectroscopy in a supersonic jet. , 1982, Optics letters.

[31]  W. Green,et al.  A Signature of Roaming Dynamics in the Thermal Decomposition of Ethyl Nitrite: Chirped-Pulse Rotational Spectroscopy and Kinetic Modeling. , 2014, The journal of physical chemistry letters.

[32]  David A. Williams,et al.  The chemistry of star-forming regions , 1999 .

[33]  Nathan A. Seifert,et al.  The interplay of hydrogen bonding and dispersion in phenol dimer and trimer: structures from broadband rotational spectroscopy. , 2013, Physical chemistry chemical physics : PCCP.

[34]  J. Hougen,et al.  The laboratory spectrum of acetaldehyde at 1 millimeter (230-325 GHz) , 1993 .

[35]  B. Drouin,et al.  Spectroscopy of the ground, first and second excited torsional states of acetaldehyde from 0.05 to 1.6 THz , 2014 .

[36]  Kirill Prozument,et al.  A chirped-pulse Fourier-transform microwave/pulsed uniform flow spectrometer. II. Performance and applications for reaction dynamics. , 2014, The Journal of chemical physics.

[37]  Germany,et al.  Molecules at z = 0.89 - A 4-mm-rest-frame absorption-line survey toward PKS 1830−211 , 2011, 1104.3361.

[38]  W. Flygare,et al.  Fabry–Perot cavity pulsed Fourier transform microwave spectrometer with a pulsed nozzle particle source , 1981 .

[39]  S. Charnley.  Acetaldehyde in star-forming regions , 2004 .

[40]  E. Herbst,et al.  A new analysis and additional measurements of the millimeter and submillimeter spectrum of methanol , 1984 .

[41]  A. Bauder,et al.  Microwave spectrum of acetaldehyde-1-d1: Deuterium quadrupole splittings and internal rotation analysis , 1989 .

[42]  S. Klippenstein,et al.  Resolving Some Paradoxes in the Thermal Decomposition Mechanism of Acetaldehyde. , 2015, The journal of physical chemistry. A.

[43]  E. B. Wilson,et al.  ON THE ORIGIN OF POTENTIAL BARRIERS TO INTERNAL ROTATION IN MOLECULES. , 1957, Proceedings of the National Academy of Sciences of the United States of America.

[44]  R. Lees,et al.  Torsion–Vibration–Rotation Interactions in Methanol. I. Millimeter Wave Spectrum , 1968 .

[45]  W. Obert,et al.  Cluster Formation in Expanding Supersonic Jets: Effect of Pressure, Temperature, Nozzle Size, and Test Gas , 1972 .

[46]  R. Campargue.  Progress in overexpanded supersonic jets and skimmed molecular beams in free-jet zones of silence , 1984 .

[47]  E. Herbst,et al.  The millimeter-wave spectrum of acetaldehyde in its two lowest torsional states , 1986 .

[48]  R. Smalley,et al.  Molecular optical spectroscopy with supersonic beams and jets , 1977 .

[49]  Daniel P Zaleski,et al.  A perspective on chemistry in transient plasma from broadband rotational spectroscopy. , 2014, Physical chemistry chemical physics : PCCP.

[50]  J. Hougen,et al.  The Third and Fourth Torsional States of Acetaldehyde , 1996 .

[51]  Brooks H. Pate,et al.  Broadband Fourier transform rotational spectroscopy for structure determination: The water heptamer , 2013 .

[52]  Brooks H. Pate,et al.  The rotational spectrum of epifluorohydrin measured by chirped-pulse Fourier transform microwave spectroscopy , 2006 .

[53]  J. T. Hougen,et al.  Rho-axis-method Hamiltonian for molecules having one methyl rotor and C1 point-group symmetry at equilibrium , 2003 .

[54]  R. Garrod,et al.  Complex Chemistry in Star-forming Regions: An Expanded Gas-Grain Warm-up Chemical Model , 2008, 0803.1214.

[55]  Bernard Kirtman,et al.  Interactions between Ordinary Vibrations and Hindered Internal Rotation. I. Rotational Energies , 1962 .

[56]  D. Plusquellic,et al.  Segmented chirped-pulse Fourier transform submillimeter spectroscopy for broadband gas analysis. , 2013, Optics express.

[57]  N. Fourikis,et al.  Microwave Emission of the 211?212 Rotational Transition in Interstellar Acetaldehyde , 1974 .