TY - JOUR
T1 - Rotational spectrum and structure of the T-shaped cyanoacetylene carbon dioxide complex, HCCCN⋯CO2
AU - Kang, Lu
AU - Davis, Philip
AU - Dorell, Ian
AU - Li, Kexin
AU - Oncer, Onur
AU - Wang, Lucy
AU - Novick, Stewart E.
AU - Kukolich, Stephen G.
N1 - Funding Information:
P. D. and I. D. wish to thank the Department of Physics of Kennesaw State University for the undergraduate traveling fund. S. E. N. acknowledges the support from NSF under the Grant No. CHE-1565276 . This material is based upon work partially supported by NSF under the Grant No. CHE-1057796 to the University of Arizona (S. K.).
Funding Information:
P. D. and I. D. wish to thank the Department of Physics of Kennesaw State University for the undergraduate traveling fund. S. E. N. acknowledges the support from NSF under the Grant No. CHE-1565276. This material is based upon work partially supported by NSF under the Grant No. CHE-1057796 to the University of Arizona (S. K.).
Publisher Copyright:
© 2017 Elsevier Inc.
PY - 2017/12
Y1 - 2017/12
N2 - The rotational spectrum of the T-shaped cyanoacetylene carbon dioxide dimer, HCCCN⋯CO2, was measured using two Balle-Flygare Fourier transform microwave (FTMW) spectrometers between 1.4 GHz and 25 GHz. Only the Ka = 0, 2, 4 branches of spectrum from J′ = 1 ← 0 to J″ = 16 ← 15 transitions were observed. The vanishing of the Ka = 1, 3, … transitions demonstrates a C2v symmetry complex with a T-shaped alignment of the subunits. The spectroscopic constants were fit using Pickett's SPFIT/SPCAT suite of programs obtaining: A0 = 11273(18) MHz, B0 = 764.088(21) MHz, C0 = 716.254(21) MHz, ΔJ = 0.50329(34) kHz, ΔJK = 0.120867(11) MHz, ΔK = −28.17(36) MHz, δJ = 0.0613(21) kHz, δK = 44.25(95) kHz, ΦJ = 0.0053(12) Hz, ΦJK = 9.820(55) Hz, ΦKJ = −0.59325(72) kHz, ΦK = −2.3719(53) MHz, ϕJ = 0.0398(42) Hz, ϕJK = 6.9(9) Hz, and ϕK = −3.592(13) kHz. The 14N nuclear quadrupole coupling constants were fit to χaa = −4.12753(38) MHz and χbb − χcc = 0.103(15) MHz. The small negative inertial defect, Δ0 = −0.66(12) u Å2, indicates a vibrationally averaged planar complex with non-negligible low frequency out-of-plane vibrations. While maintaining near-planar orientation, both binding partners exhibit large-amplitude bending vibrations within the plane. To deal with the intermolecular dynamics, a torsional oscillation model was developed in this work for the structural analysis. According to this model, the vibrational bending amplitude for HCCCN torsional angle is 10.(1)°, with the a-axis of complex; CO2 subtending a 5.4(5)° torsional oscillation angle with the b molecular axis. The van der Waals bond length is 3.0137(3) Å. The stretching force constant, ks = 3.9 N/m, and the stretching frequency, νs = 53 cm−1, for the van der Waals bond were calculated using the pseudo-diatomic model. High-level MP2 and DFT calculations of structural parameters, rotational constants, and 14N quadrupole coupling strengths were made and the results compared with experimental results.
AB - The rotational spectrum of the T-shaped cyanoacetylene carbon dioxide dimer, HCCCN⋯CO2, was measured using two Balle-Flygare Fourier transform microwave (FTMW) spectrometers between 1.4 GHz and 25 GHz. Only the Ka = 0, 2, 4 branches of spectrum from J′ = 1 ← 0 to J″ = 16 ← 15 transitions were observed. The vanishing of the Ka = 1, 3, … transitions demonstrates a C2v symmetry complex with a T-shaped alignment of the subunits. The spectroscopic constants were fit using Pickett's SPFIT/SPCAT suite of programs obtaining: A0 = 11273(18) MHz, B0 = 764.088(21) MHz, C0 = 716.254(21) MHz, ΔJ = 0.50329(34) kHz, ΔJK = 0.120867(11) MHz, ΔK = −28.17(36) MHz, δJ = 0.0613(21) kHz, δK = 44.25(95) kHz, ΦJ = 0.0053(12) Hz, ΦJK = 9.820(55) Hz, ΦKJ = −0.59325(72) kHz, ΦK = −2.3719(53) MHz, ϕJ = 0.0398(42) Hz, ϕJK = 6.9(9) Hz, and ϕK = −3.592(13) kHz. The 14N nuclear quadrupole coupling constants were fit to χaa = −4.12753(38) MHz and χbb − χcc = 0.103(15) MHz. The small negative inertial defect, Δ0 = −0.66(12) u Å2, indicates a vibrationally averaged planar complex with non-negligible low frequency out-of-plane vibrations. While maintaining near-planar orientation, both binding partners exhibit large-amplitude bending vibrations within the plane. To deal with the intermolecular dynamics, a torsional oscillation model was developed in this work for the structural analysis. According to this model, the vibrational bending amplitude for HCCCN torsional angle is 10.(1)°, with the a-axis of complex; CO2 subtending a 5.4(5)° torsional oscillation angle with the b molecular axis. The van der Waals bond length is 3.0137(3) Å. The stretching force constant, ks = 3.9 N/m, and the stretching frequency, νs = 53 cm−1, for the van der Waals bond were calculated using the pseudo-diatomic model. High-level MP2 and DFT calculations of structural parameters, rotational constants, and 14N quadrupole coupling strengths were made and the results compared with experimental results.
UR - https://www.scopus.com/pages/publications/85025123083
UR - https://www.scopus.com/pages/publications/85025123083#tab=citedBy
U2 - 10.1016/j.jms.2017.07.001
DO - 10.1016/j.jms.2017.07.001
M3 - Article
AN - SCOPUS:85025123083
SN - 0022-2852
VL - 342
SP - 62
EP - 72
JO - Journal of Molecular Spectroscopy
JF - Journal of Molecular Spectroscopy
ER -