ECON 1 Lecture Notes - Lecture 7: Xenon Tetrafluoride, Lewis Structure, Chlorine Trifluoride
Document Summary
Count number of e pairs (bonding or lp) in the valence shell of the central atom. Assume e arrange themselves to minimise unfavourable electrostatic repulsion. If central atom has no lp then epg and mg same. Trigonal bipyramidal = 90 bond angle and 120 bond angle (equatorial) If central atom has lone pairs need to decide which position they occupy. If 4 bp 1 lp then can either put a lp in an axial position or an equatorial position. The mg is t-shaped as the 2 lps are in the equatorial positions. The epg for xef4 is 6 regions of electron density and therefore octahedral, the molecular geometry is 4 making it square planar with the 2 lps occupying the top spaces. Bonding pairs go to the more electronegative substituents in order to occupy less space. Vsepr theory multiple bonds count as one electron region. However: higher electron density means more space. Multiple bonds placed where repulsions are minimised.
