Point groups assignment

Figure B.2 Flow chart for point-group assignment. A symmetry plane that is perpendicular to a proper axis of rotation is a <7 , plane, one that includes the unique proper axis of rotation is a cr plane, and one that includes the highest order proper axis of rotation and bisects the remaining two-fold axes of rotation is a a, plane...

A chemist isolated an unknown transition metal complex with a formula of ABe. Five potential structures were considered, belonging to point groups C, Dih, D6h, Dlh, and Djj. Spectroscopic studies led to the conclusion that the p orbitals originating on A in the complex were completely nondegenerate. Sketch a structural formula that is consistent with each of the five point group assignments and decide which structures can be eliminated on the basis of the experimental results. 

Figure 2.32. Examples of symmetry group elements and molecular point group assignments.

FIGURE 4-7 Diagram of the Point Group Assignment Method. 

Matching the symmetry operations of a molecule with those listed in the top row of the character table will confirm any point group assignment. 

While Figure 3.10 provides a point group assignment using certain diagnostic symmetry elements, it may be necessary to establish whether any additional symmetry elements are exhibited by a molecule in a given point group. 

By considering the structures of the following molecules, confirm that the point group assignments are correct ... 

While point group assignments have not yet been made, the molecules are now divided into two major categories, the D set and the C or 5 set. 

We have only one example in our list that falls into the S2 groups, as seen in Figure 4.12. A flowchart that summarizes this point group assignment method is given in Figure 4.7, and more examples are given in Table 4.4. 

More detailed questions can be added to these broad categorizations to allow a point group assignment to be made. One strategy is summarized in the flow diagram shown in Figure 3.29, and in the following sections we will apply this approach to some example structures. 

Example Point Group Assignments 3.11.1 Example 1 Conformations of Cyclohexane... 

Figure 3.29 Flow diagram for point group assignment.

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