The rotational spectrum of pyridazine (o-C4H4N2), the ortho disubstituted nitrogen analog of benzene, has been measured and analyzed in the gas phase. For the ground vibrational state of the normal isotopolog, over 2000 individual rotational transitions have been identified between 238 and 360 GHz and have been fit to 13 parameters of a 6th-order centrifugal distortion Hamiltonian. All transitions in this frequency region can now be predicted from this model to near experimental accuracy, i.e., well enough for the purpose of any future radio-astronomical search for this species. Three isotopologs, [3-13C]-C4H4N2, [4-13C]-C4H4N2, and [1-15N]-C4H4N2, have been detected in natural abundance, and several hundred lines have been measured for each of these species and fit to 6th-order Hamiltonians. Ten additional isotopologs were synthesized with enhanced deuterium substitution and analyzed to allow for a complete structure determination. The equilibrium structure (Re) of pyridazine was obtained by correcting the experimental rotational constants for the effects of vibration-rotation coupling using interaction constants predicted from CCSD(T) calculations with an ANO0 basis set and further correcting for the effect of electron mass. The final Re structural parameters are determined with excellent accuracy, as evidenced by their ability to predict 28 independent moments of inertia (Ia and Ib for 14 isotopologs) very well from 9 structural parameters. The rotational spectra of the six lowest-energy fundamental vibrational satellites of the main isotopolog have been detected. The rotational spectra of the five lowest-energy vibrational satellites have been assigned and fit to yield accurate rotational and distortion constants, while the fit and assignment for the sixth is less complete. The resultant vibration-rotation interaction (α) constants are found to be in excellent agreement with ones predicted from coupled-cluster calculations, which proved to be the key to unambiguous assignment of the satellite spectra to specific vibration modes.
Skip Nav Destination
,
,
,
,
,
,
Article navigation
14 December 2013
Research Article|
December 10 2013
Rotational spectroscopy of pyridazine and its isotopologs from 235–360 GHz: Equilibrium structure and vibrational satellites
Brian J. Esselman;
Brian J. Esselman
1Department of Chemistry,
University of Wisconsin–Madison
, Madison, Wisconsin 53706, USA
Search for other works by this author on:
Brent K. Amberger;
Brent K. Amberger
1Department of Chemistry,
University of Wisconsin–Madison
, Madison, Wisconsin 53706, USA
Search for other works by this author on:
Joshua D. Shutter;
Joshua D. Shutter
1Department of Chemistry,
University of Wisconsin–Madison
, Madison, Wisconsin 53706, USA
Search for other works by this author on:
Mitchell A. Daane;
Mitchell A. Daane
1Department of Chemistry,
University of Wisconsin–Madison
, Madison, Wisconsin 53706, USA
Search for other works by this author on:
John F. Stanton;
John F. Stanton
2Institute for Theoretical Chemistry, Departments of Chemistry and Biochemistry,
The University of Texas–Austin
, Austin, Texas 78712, USA
Search for other works by this author on:
R. Claude Woods;
R. Claude Woods
1Department of Chemistry,
University of Wisconsin–Madison
, Madison, Wisconsin 53706, USA
Search for other works by this author on:
Robert J. McMahon
Robert J. McMahon
1Department of Chemistry,
University of Wisconsin–Madison
, Madison, Wisconsin 53706, USA
Search for other works by this author on:
Brian J. Esselman
1
Brent K. Amberger
1
Joshua D. Shutter
1
Mitchell A. Daane
1
John F. Stanton
2
R. Claude Woods
1
Robert J. McMahon
1
1Department of Chemistry,
University of Wisconsin–Madison
, Madison, Wisconsin 53706, USA
2Institute for Theoretical Chemistry, Departments of Chemistry and Biochemistry,
The University of Texas–Austin
, Austin, Texas 78712, USA
J. Chem. Phys. 139, 224304 (2013)
Article history
Received:
September 30 2013
Accepted:
November 08 2013
Citation
Brian J. Esselman, Brent K. Amberger, Joshua D. Shutter, Mitchell A. Daane, John F. Stanton, R. Claude Woods, Robert J. McMahon; Rotational spectroscopy of pyridazine and its isotopologs from 235–360 GHz: Equilibrium structure and vibrational satellites. J. Chem. Phys. 14 December 2013; 139 (22): 224304. https://doi.org/10.1063/1.4832899
Download citation file:
Pay-Per-View Access
$40.00
Sign In
You could not be signed in. Please check your credentials and make sure you have an active account and try again.
Citing articles via
DeePMD-kit v2: A software package for deep potential models
Jinzhe Zeng, Duo Zhang, et al.
CREST—A program for the exploration of low-energy molecular chemical space
Philipp Pracht, Stefan Grimme, et al.
Related Content
Millimeter-wave and high-resolution infrared spectroscopy of the low-lying vibrational states of pyridazine isotopologues
J. Chem. Phys. (May 2024)
Molecular structure determination: Equilibrium structure of pyrimidine (m-C4H4N2) from rotational spectroscopy (reSE) and high-level ab initio calculation (re) agree within the uncertainty of experimental measurement
J. Chem. Phys. (March 2020)
On equilibrium structures of the water molecule
J. Chem. Phys. (June 2005)