Why does it minimize electron repulsion for lone pairs to be located on the equatorial axis in a t-shaped molecule?

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Katherine Fitzgerald 1A
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Why does it minimize electron repulsion for lone pairs to be located on the equatorial axis in a t-shaped molecule?

Postby Katherine Fitzgerald 1A » Tue Jul 30, 2019 10:11 am

Why does it minimize electron repulsion for lone pairs to be located on the equatorial axis in a t-shaped molecule? I would think placing them at the "north" and "south" poles of the equator would minimize repulsion between the lone pairs since they would be 180 degrees apart

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Re: Why does it minimize electron repulsion for lone pairs to be located on the equatorial axis in a t-shaped molecule?

Postby Chem_Mod » Tue Jul 30, 2019 12:48 pm

90 degree interactions between lone pairs and bonding pairs should be avoided. If the lone pairs occupy the axial positions, there will be 6 of these. If the lone pairs occupy the equatorial positions, the number of these unfavorable interactions will be reduced to 4 (and though the lone pairs themselves will be 120 rather than 180 degrees apart, this is acceptable).


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