厦门大学：《结构化学 Structural Chemistry》课程教学资源（课件讲稿）Chapter 3 Molecular symmetry and symmetry point group

For example The principle rotation axis is the axis of the highest fold. 6

C5 For example The principle rotation axis is the axis of the highest fold. C6

4)Reflection and the Mirror plane (o) If reflection of an object through a plane produces an indistinguishable configuration then that plane is a plane of symmetry(mirror plane) denoted o. (xy,z) 6 0 0 (x,y,-z) 6对

 If reflection of an object through a plane produces an indistinguishable configuration then that plane is a plane of symmetry (mirror plane) denoted . 4) Reflection and the Mirror plane ()     0 0 1 0 1 0 1 0 0  xy         zyx zyx zyx xy 0 0 1 0 1 0 1 0 0  （x, y,-z） z （x,y,z） y x

>There are three types of mirror planes: -If the plane is perpendicular to the vertical principle axis then it labeled o -If the plane contains the principle axis then it is labeled o -If a o plane contains the principle axis and bisects the angle between two adjacent 2-fold axes then it is labeled oa

There are three types of mirror planes: If the plane is perpendicular to the vertical principle axis then it labeled h. If the plane contains the principle axis then it is labeled v. If a  plane contains the principle axis and bisects the angle between two adjacent 2-fold axes then it is labeled d

If the plane is perpendicular to the vertical principle axis then it labeled on. Example:BF3 also has a on plane of symmetry. C3 m s M9

If the plane is perpendicular to the vertical principle axis then it labeled h. • Example: BF3 also has a h plane of symmetry

If the plane contains the principle axis then it is labeledo. ·Example:Water -Has a C2 principle axis. -Has two planes that contain the principle axis,o ando. ………

If the plane contains the principle axis then it is labeled v. • Example: Water – Has a C2 principle axis. – Has two planes that contain the principle axis, v and v’. H H O v v