Molecular geometry seesaw

Because equatorial and axial positions differ, two molecular geometries are possible for SF4. As Figure 9-22 shows, placing the lone pair in an axial position gives a trigonal pyramid, whereas placing the lone pair in an equatorial position gives a seesaw shape. 

Sulfur tetrafluoride has two possible molecular geometries. The stable isomer is the seesaw form. 

C09-0129. Tellurium compounds, which are toxic and have a hideous stench, must be handled with extreme care. Predict the formula of the tellurium-fluorine molecule or ion that has the following molecular geometry (a) bent (b) T-shaped (c) square pyramid (d) trigonal bipyramid (e) octahedron and (Q seesaw. 

The Lewis formula shows 5 electron groups around the central S atom and its electronic geometry is trigonal bipyramidal. The molecular geometry is a seesaw due to the presence of 1 lone pair of electrons on the central S atom. 

Seesaw molecular geometty Example SF4 T-shaped molecular geometry Examples CIF3, Brp3 Linear molecular geometry Examples XeF2, F ... 

Seesaw A term used to describe the molecular geometry of a molecule or polyatomic ion that has four atoms bonded to a central atom and one unshared pair on the central atom (AB4U). 

The sulfur has five electron domains around it four from the S — F bonds and one from the nonbonding pair. Each domain points toward a vertex of a trigonal bipyramid. The domain from the nonbonding pair wUl point toward an equatorial position. The four bonds point toward the remaining four positions, resulting in a molecular geometry that is described as seesaw-shaped ... 

In all of the above cases, the feometry is in afreement with the expectations of the valence shell electron pair repulsion (VSEPR) model of Gillespie and Nyholm [77]. The VSEPR model accounts for the molecular geometry in nearly all cases for main group elements in free molecules. Deviations are observed in solids because of the contribution from the lattice energy. For example, in SnO and red PbO, the coordination MO4E is square pyramidal, instead of seesaw expected by the VSEPR model [78,79]. 

I The seesaw molecular geometry Is sometimes I called an irregular tetrahedron. 

Practice Problem B For which molecular geometries (linear, bent, trigonal planar, trigonal pyramidal, tetrahedral, square planar, T-shaped, seesaw-shaped, trigonal bipyramidal, square pyramidal, octahedral) can an AB, molecule be nonpolar if there are (a) two drflerent types of terminal atoms and (b) three different types of terminal atoms ... 

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