Title: | The rotational spectre of cyanoacetylene dimer, H-C-C-C-N ••• H-C-C-C-N |

Author(s): | Davis, Philip |

Contributor(s): | Novick, Stewart E.; Kukolich, Stephen G.; Daly, Adam M.; Li, Kexin; Dorell, Ian; Kang, Lu |

Subject(s): | Spectroscopy of Large Amplitude Motions |

Abstract: | The rotational spectra of H-C-C-C-N ••• H-C-C-C-N, cyanoacetylene dimer,were recorded using Balle-Flygare type Fourier transform microwave (FTMW) spectrometers at Wesleyan and Arizona. The low-J transitions were measured down to 1.3 GHz at very high resolution, FWHM ~1 kHz using a large-cavity spectrometer. The spectral hyperfine structure due to the $^{14}$N 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: B$_0$ = 339.292331(8) MHz, D$_J$ = 32.15(8) Hz, H = -0.0015(2) Hz, eqQ($^{14}$N$_1$) = -3.990(1) MHz, and eqQ($^{14}$N$_2$) = -4.171(1) MHz. The vibrationally averaged dimer configuration is \\ H-C-C-C-N$_1$ ••• H-C-C-C-N$_2$. Using a simple linear model, the vibrational ground state and the equilibrium hydrogen bond lengths are determined to be: r$_0$(N ••• H) = 2.2489(3) \AA and r$_e$(N ••• H) = 2.2315 \AA. The equilibrium center-of-mass distance between the two HCCCN subunits is = 7.0366 \AA. 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$_1$ ••• H-C-C-C-N$_2$ are = 7.0603 \AA, $\theta$$_1$ = $13^{\circ}$, and $\theta$$_2$ = $8.7^{\circ}$, 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. |

Issue Date: | 2016-06-22 |

Publisher: | International Symposium on Molecular Spectroscopy |

Genre: | Conference Paper/Presentation |

Type: | Text |

Language: | En |

URI: | http://hdl.handle.net/2142/91067 |

Rights Information: | Copyright 2016 by the authors |

Date Available in IDEALS: | 2016-08-22 |