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Equilibrium Structure and Spectroscopic Constants of Difluorovinylidene: An ab Initio Study
1Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr, D-45470, Germany
Journal of Molecular Spectroscopy
|January 10, 2001
Summary
This study presents highly correlated ab initio calculations for difluorovinylidene (F2CC), determining its precise equilibrium geometry and vibrational frequencies. These theoretical findings align well with experimental data, offering insights into molecular structure and reactivity.
Area of Science:
- Computational Chemistry
- Quantum Chemistry
- Molecular Spectroscopy
Background:
- Difluorovinylidene (F2CC) is a reactive intermediate.
- Accurate theoretical characterization is crucial for understanding its properties.
Purpose of the Study:
- To perform high-level ab initio calculations for difluorovinylidene (F2CC).
- To determine its equilibrium geometry, vibrational frequencies, and spectroscopic constants.
- To investigate the isomerization energy and barrier to difluoroethyne (FCCF).
Main Methods:
- Coupled cluster calculations with the singles and doubles, and perturbative triples (CCSD(T)) method.
- Large augmented correlation-consistent polarized valence quadruple zeta (aug-cc-pVQZ) basis sets.
- Core correlation effects were included for accurate geometry determination.
Main Results:
- A reliable theoretical equilibrium geometry for F2CC was derived: r(e)(CC) = 134.74(10) pm, r(e)(CF) = 131.00(10) pm, and angle(e)(FCC) = 123.23(10) degrees.
- Theoretical vibrational wavenumbers showed excellent agreement with experimental matrix-isolation data.
- Spectroscopic constants were predicted, and isomerization energetics were refined.
Conclusions:
- The study provides accurate theoretical data for difluorovinylidene.
- The findings support experimental observations and enhance understanding of F2CC's molecular characteristics.
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