CHEM 211 Lecture 1: 2b.docx

• School: Queen's University
• Department: Chemistry
• Course: CHEM 211
• Professor: Philip G Jessop

Document Summary

S4 = c2, categorize s group only if no cs or existing cs are dependent on the s axis, s"s must be an even number and greater than 2. Point groups: set of symmetry elements: four general categories, nonrotational groups (c1,cs,ci, single-axis groups: (cn, cnv, cnh, s2n, c v, dihedral groups (dn, dnv, dnh, d h, cubic groups (td, oh, ih,) Horizontal through the centre coming out of page between centre and upper groups no mirror plane: e, s4 principle axis, c2 is not independent of the s axis, therefore an s group called point. If n=4, then it would be s8, however an independent c axis exists. Always has n c2"s perpendicular to the principle axis. Be able to pick out c"s and s"s in a cubic point group! List symmetry elements, then find point groups cis-[pf2cl4]- c2v. Timescales: movement of the molecule and change the point group, ex. staggered and eclipse are different point groups.