TY - JOUR
T1 - Rotational spectra and nitrogen nuclear quadrupole coupling for the cyanoacetylene dimer
T2 - H-C≡C-C≡N⋯H-C≡C-C≡N
AU - Kang, Lu
AU - Davis, Philip
AU - Dorell, Ian
AU - Li, Kexin
AU - Daly, Adam
AU - Novick, Stewart E.
AU - Kukolich, Stephen G.
N1 - Funding Information:
We would like to thank Michael Barfield for his help with ab initio calculations. P.D. and I.D. wish to thank the Department of Astronomy and Physics of Kennesaw State University for the undergraduate traveling fund. S.E.N. acknowledges the support from NSF under the Grant No. CHE-1011214 . This material is based upon work partially supported by the National Science Foundation Grant No. CHE-1057796 to the University of Arizona (S.K.).
Publisher Copyright:
© 2016 Elsevier Inc.
Copyright:
Copyright 2018 Elsevier B.V., All rights reserved.
PY - 2016/3/1
Y1 - 2016/3/1
N2 - The rotational spectra of cyanoacetylene dimer, H-C≡C-C≡N⋯H-C≡C-C≡N, were recorded using Balle-Flygare type Fourier transform microwave (FTMW) spectrometers. The low J transitions were measured down to 1.3 GHz at very high resolution, FWHM ∼ 1 kHz. The spectral hyperfine structure due to the 14N nuclear quadrupole coupling interactions is well-resolved below 4 GHz using a low frequency spectrometer at the University of Arizona. The experimental spectroscopic constants were fitted as: B0 = 339.2923310(79) MHz, DJ = 32.152(82) Hz, H = -0.00147(20) Hz, eqQ(14N1) = -3.9902(14) MHz, and eqQ(14N2) = -4.1712(13) MHz. The vibrationally averaged dimer configuration is H-C≡C-C≡N⋯H-C≡C-C≡N. Using a simple linear model, the vibrational ground state and the equilibrium hydrogen bond lengths are determined to be: r0(N⋯H) = 2.2489(3) Å and re(N⋯H) = 2.2315 Å. The equilibrium center-of-mass distance between the two HCCCN subunits is rcom = 7.0366 Å. Using the rigid precession model, the vibrational ground state center-of-mass distance and the pivot angles which HCCCN subunits make with the a-axis of H-C≡C-C≡N⋯H-C≡C-C≡N are rc.m. = 7.0603 Å, θ1 = 13.0°, and θ2 = 8.7°, respectively. The calculated hydrogen bond energy of H-C≡C-C≡N⋯H-C≡C-C≡N is 1466 cm-1 using the MP2/aug-cc-PVTZ method in present work.
AB - The rotational spectra of cyanoacetylene dimer, H-C≡C-C≡N⋯H-C≡C-C≡N, were recorded using Balle-Flygare type Fourier transform microwave (FTMW) spectrometers. The low J transitions were measured down to 1.3 GHz at very high resolution, FWHM ∼ 1 kHz. The spectral hyperfine structure due to the 14N nuclear quadrupole coupling interactions is well-resolved below 4 GHz using a low frequency spectrometer at the University of Arizona. The experimental spectroscopic constants were fitted as: B0 = 339.2923310(79) MHz, DJ = 32.152(82) Hz, H = -0.00147(20) Hz, eqQ(14N1) = -3.9902(14) MHz, and eqQ(14N2) = -4.1712(13) MHz. The vibrationally averaged dimer configuration is H-C≡C-C≡N⋯H-C≡C-C≡N. Using a simple linear model, the vibrational ground state and the equilibrium hydrogen bond lengths are determined to be: r0(N⋯H) = 2.2489(3) Å and re(N⋯H) = 2.2315 Å. The equilibrium center-of-mass distance between the two HCCCN subunits is rcom = 7.0366 Å. Using the rigid precession model, the vibrational ground state center-of-mass distance and the pivot angles which HCCCN subunits make with the a-axis of H-C≡C-C≡N⋯H-C≡C-C≡N are rc.m. = 7.0603 Å, θ1 = 13.0°, and θ2 = 8.7°, respectively. The calculated hydrogen bond energy of H-C≡C-C≡N⋯H-C≡C-C≡N is 1466 cm-1 using the MP2/aug-cc-PVTZ method in present work.
KW - Hydrogen bonding
KW - Microwave spectrum
KW - Quadrupole coupling
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U2 - 10.1016/j.jms.2016.01.008
DO - 10.1016/j.jms.2016.01.008
M3 - Article
AN - SCOPUS:84957583588
VL - 321
SP - 5
EP - 12
JO - Journal of Molecular Spectroscopy
JF - Journal of Molecular Spectroscopy
SN - 0022-2852
ER -