skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: 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

Journal Article · · Journal of Chemical Physics
DOI:https://doi.org/10.1063/1.5144914· OSTI ID:1800415
ORCiD logo [1];  [1]; ORCiD logo [1]; ORCiD logo [2]; ORCiD logo [1]; ORCiD logo [1]
  1. Univ. of Wisconsin, Madison, WI (United States)
  2. Univ. of Florida, Gainesville, FL (United States)
+ Show Author Affiliations

The pure rotational spectrum of pyrimidine (m-C4H4N2), the meta-substituted dinitrogen analog of benzene, has been studied in the millimeter-wave region from 235 GHz to 360 GHz. The rotational spectrum of the ground vibrational state has been assigned and fit to yield accurate rotational and distortion constants. Over 1700 distinct transitions were identified for the normal isotopologue in its ground vibrational state and least-squares fit to a partial sextic S-reduced Hamiltonian. Transitions for all four singly substituted 13C and 15N isotopologues were observed at natural abundance and were likewise fit. Deuterium-enriched samples of pyrimidine were synthesized, giving access to all eleven possible deuterium-substituted isotopologues, ten of which were previously unreported. Experimental values of rotational constants and computed values of vibration–rotation interaction constants and electron-mass corrections were used to determine semi-experimental equilibrium structures (reSE) of pyrimidine. The reSE structure obtained using coupled-cluster with single, double, and perturbative triple excitations [CCSD(T)] corrections shows exceptional agreement with the re structure computed at the CCSD(T)/cc-pCV5Z level (≤0.0002 Å in bond distance and ≤0.03° in bond angle). Of the various computational methods examined, CCSD(T)/cc-pCV5Z is the only method for which the computed value of each geometric parameter lies within the statistical experimental uncertainty (2σ) of the corresponding semi-experimental coordinate. The exceptionally high accuracy and precision of the structure determination is a consequence of the large number of isotopologues measured, the precision and extent of the experimental frequency measurements, and the sophisticated theoretical treatment of the effects of vibration–rotation coupling and electron mass. Taken together, these demanding experimental and computational studies establish the capabilities of modern structural analysis for a prototypical monocyclic aromatic compound.

Research Organization:
Univ. of Hawaii, Honolulu, HI (United States)
Sponsoring Organization:
USDOE Office of Science (SC)
Grant/Contract Number:
FG02-07ER15885; DEFG02-07ER15885
OSTI ID:
1800415
Alternate ID(s):
OSTI ID: 1604238
Journal Information:
Journal of Chemical Physics, Vol. 152, Issue 10; ISSN 0021-9606
Publisher:
American Institute of Physics (AIP)Copyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 36 works
Citation information provided by
Web of Science

References (46)

Rotational spectrum of trans–trans diethyl ether in the ground and three excited vibrational states journal October 2005
Analytic energy gradients for the spin-free exact two-component theory using an exact block diagonalization for the one-electron Dirac Hamiltonian journal August 2011
Endogenous production, exogenous delivery and impact-shock synthesis of organic molecules: an inventory for the origins of life journal January 1992
Quadratic configuration interaction. A general technique for determining electron correlation energies journal November 1987
Analytic gradients for coupled‐cluster energies that include noniterative connected triple excitations: Application to c i s ‐ and t r a n s ‐HONO journal May 1991
The Photochemistry of Pyrimidine in Realistic Astrophysical ices and the Production of Nucleobases journal September 2014
Molecular equilibrium structures from experimental rotational constants and calculated vibration–rotation interaction constants journal April 2002
Millimeter-wave spectroscopy of carbonyl diazide, OC(N3)2 journal January 2014
Detection of C60 and C70 in a Young Planetary Nebula journal July 2010
Semi-Experimental Equilibrium Structure Determinations by Employing B3LYP/SNSD Anharmonic Force Fields: Validation and Application to Semirigid Organic Molecules journal February 2015
Gaussian basis sets for use in correlated molecular calculations. I. The atoms boron through neon and hydrogen journal January 1989
Integrated computational approaches for spectroscopic studies of molecular systems in the gas phase and in solution: pyrimidine as a test case journal April 2012
Accuracy and Interpretability: The Devil and the Holy Grail. New Routes across Old Boundaries in Computational Spectroscopy journal June 2019
Infrared spectra of pyrazine, pyrimidine and pyridazine in solid argon journal April 2006
Magnetic interactions in molecules and an analysis of molecular electronic charge distribution from magnetic parameters journal December 1974
Detection of the aromatic molecule benzonitrile ( c -C 6 H 5 CN) in the interstellar medium journal January 2018
Formation and photostability of N-heterocycles in space: I. The effect of nitrogen on the photostability of small aromatic molecules journal March 2005
The microwave spectrum, dipole moment, and nuclear quadrupole coupling constants of pyrimidine journal September 1970
Coupled-cluster methods including noniterative corrections for quadruple excitations journal August 2005
Semiexperimental Equilibrium Structures for Building Blocks of Organic and Biological Molecules: The B2PLYP Route journal August 2015
Precise equilibrium structure determination of hydrazoic acid (HN 3 ) by millimeter-wave spectroscopy journal September 2015
A search for interstellar pyrimidine journal October 2003
Analytic evaluation of energy gradients for the singles and doubles coupled cluster method including perturbative triple excitations: Theory and applications to FOOF and Cr 2 journal January 1991
Density‐functional thermochemistry. III. The role of exact exchange journal April 1993
[ITAL]Infrared Space Observatory's[/ITAL] Discovery of C[TINF]4[/TINF]H[TINF]2[/TINF], C[TINF]6[/TINF]H[TINF]2[/TINF], and Benzene in CRL 618 journal January 2001
Exact two-component Hamiltonians revisited journal July 2009
Polycyclic aromatic hydrocarbons, carbon nanoparticles and the diffuse interstellar bands journal January 2006
Nucleobases and Prebiotic Molecules in Organic Residues Produced from the Ultraviolet Photo-Irradiation of Pyrimidine in NH 3 and H 2 O+NH 3 Ices journal April 2012
Gaussian basis sets for use in correlated molecular calculations. V. Core‐valence basis sets for boron through neon journal September 1995
General contraction of Gaussian basis sets. I. Atomic natural orbitals for first‐ and second‐row atoms journal April 1987
The diffuse interstellar bands: A major problem in astronomical spectroscopy journal July 2006
Interfacing relativistic and nonrelativistic methods. IV. One- and two-electron scalar approximations journal November 2001
Easy assignment of rotational spectra of slightly abundant isotopic species in natural abundance: 13C and 15N isotopic species of pyrimidine journal May 1991
Rotational spectroscopy of pyridazine and its isotopologs from 235–360 GHz: Equilibrium structure and vibrational satellites journal December 2013
Astronomical searches for nitrogen heterocycles journal January 2005
Equilibrium geometries of cyclic SiC 3 isomers journal February 2001
Perspective: The first ten years of broadband chirped pulse Fourier transform microwave spectroscopy journal May 2016
Variations in the Peak Position of the 6.2 μm Interstellar Emission Feature: A Tracer of N in the Interstellar Polycyclic Aromatic Hydrocarbon Population journal October 2005
Self‐consistent molecular orbital methods 25. Supplementary functions for Gaussian basis sets journal April 1984
Laboratory confirmation of C60+ as the carrier of two diffuse interstellar bands journal July 2015
Investigation of the Rotational Spectrum of Pyrimidine from 3 to 337 GHz: Molecular Structure, Nuclear Quadrupole Coupling, and Vibrational Satellites journal June 1999
Determination of Molecular Structure from Microwave Spectroscopic Data journal January 1953
Broadband rotational spectroscopy of acrylonitrile: Vibrational energies from perturbations journal October 2012
The equilibrium structure and fundamental vibrational frequencies of dioxirane journal May 1998
Development of the Colle-Salvetti correlation-energy formula into a functional of the electron density journal January 1988
Equilibrium Structures of Three-, Four-, Five-, Six-, and Seven-Membered Unsaturated N-Containing Heterocycles journal September 2014

Similar Records

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
Chemistry
Physics
Computational methods
Astrochemistry
Ab-initio methods
Radio spectrum
Molecular structure
Density functional theory
Vibrational states
Rotational spectra
Coupling constants
Rotational spectroscopy