The molecular structure of ortho- and meta-fluorobenzaldehyde by joint analysis of gas electron diffraction, microwave spectroscopy and ab initio molecular orbital calculations

• Published in: Journal of molecular structure 1998-02, Vol.443 (1), p.9-16
• Main Authors: Strand, T.G., Tafipolsky, M.A., Vilkov, L.V., Volden, H.V.
• Format: Article
• Language: English
• Subjects: Ab initio calculations; Benzene derivatives; Electron diffraction
• ISSN: 0022-2860; 1872-8014
• DOI: 10.1016/S0022-2860(97)00365-7

The molecular structures of gaseous o-fluorobenzaldehyde and m-fluorobenzaldehyde have been determined by a joint analysis of gas electron diffraction data, rotational constants from microwave spectroscopy, and constrained by results from ab initio calculations (at HF/6-331G∗∗ level). The torsion of the formyl group has been treated as a large-amplitude motion. The most important structure parameters ( r g)) from the joint analysis with estimated total errors (in parentheses) are for o-fluorobenzaldehyde: ( C C) mean = 1.3999(2) A ̊ , C F = 1.334(5) A ̊ , C C( O = 1.515(6) A ̊ , C O = 1.216(3) A ̊ , ∠CC FC = 122.0(2)°, ∠CC CHOC = 120.3(6)° and for m-fluorobenzaldehyde: ( C C) mean = 1.394(2) A ̊ , C F = 1.346(4) A ̊ , C C( O = 1.494(4) A ̊ , C O = 1.201(2) A ̊ , ∠CC FC = 122.3(1)°, and ∠CC CHOC = 120.6(3)°. The scaled molecular force fields have been determined.