The molecular structure of gaseous 2-bromofuran as studied from electron diffraction and microwave data

Abstract

The molecular structure of 2-bromofuran has been studied by the gas phase electron diffraction method. The results were used in conjunction with the rotational constants in combined structure analysis. Experimental vibrational frequencies were used to conduct a normal coordinate analysis. The obtained general valence force field was employed for calculating the mean amplitudes of vibrations, coefficients of perpendicular amplitudes and corrections for vibration—rotation interaction. The force constants reproduce well the experimental frequencies of the molecule under study and of the furan molecule and its deuterated analogs. The following values of geometrical parameters are obtained assuming C 2V molecular symmetry for the furan ring. The distances r ev are given in Å, angles in degrees. The parenthesized values are three times the standard deviations. CBr 1.848(4); CC 1.425(13); CC 1.379(10); CO 1.358(9); ∠COC 106.4(4); ∠OCC 111.0(5); ∠CCBr 132.4(5). The mean amplitudes were fixed on calculated values. A comparison has been made of the obtained geometrical parameters with molecules of related structure.