Molecular parameters of excited molecules and ions—III. Geometries of dihaloethylenes in some ionic states

✍ Scribed by Chau Foo Tim

• Publisher: Elsevier Science
• Year: 1984
• Tongue: English
• Weight: 592 KB
• Volume: 40
• Category: Article
• ISSN: 1386-1425
• DOI: 10.1016/0584-8539(84)80116-6

✦ Synopsis

The vibrational fine structures of the photoelectron bands ofgem-, cis-and trans-dihaloethylenes were used in FranckkCondon factor calculations leading to the deduction of ionic geometries of these molecules. Separability of electronic and nuclear motion, constancy of electronic transition moment and photoionization cross section within vibrational progressions, as well as the harmonic oscillator treatment, were assumed to be valid in the calculations. In the determination of the signs of the changes in bond lengths and bond angles of the molecules upon ionization, different criteria were utilized with the inclusion of the nodal repulsive force model for bond angle changes. Moreover, the two mechanisms, namely, the change in bond order and the change in electrostatic interaction as proposed by Coulson and Luz were investigated and were found to be important in geometric changes upon ionization.