B

B. E. Douglas, D. H. McDaniel, J. J. Alexander, Concepts and Models of Inorganic Chemistry, 3^rd edition, John Wiley & Sons, New York, 1994, page 147.

Problem 3.4

Assign the species in Figure 3.4 to the appropriate point groups.

Answer:

(a)

no rotations, mirror through -Sn-Mn-CO plane, so the point group is C_s

(b)

A C₂ rotation through the inversion point, mirror through the Fe-P-P-Fe plane that is perpendicular to the C₂ axis, so the point group is C_2h.

(c)

methane has several noncoincidental C₃ axes and several _d mirrors, so the point group is T_d.

(d)

The highest rotation axis is a C₂, there is a C₂ perpendicular to this, and there is are mirrors containing the rotation axes, so the point group is D_2d.

(e)

The highest rotation axis is C₃, no C₂ perpendicular, no mirrors, but there is an S₆ axis, so the point group is S₆.