Help understanding how "steric effects" are distinct from "electronic effects"?
The normal distinction between &quot;steric&quot; and &quot;electronic&quot; is based on whether the effect is transmitted through space or through bonds
All the normal physical interactions we experience are arguably electronic. When you touch your desk, you feel force because of interactions between the molecules of the desk and the molecules of your hand because the molecules of one interact &quot;electrostatically&quot; with the molecules of the other.
But your hand and your desk are not bonded together.
When a noble gas condenses into a liquid, it has a finite volume. The atoms become liquid because there are weak attractive forces (not usually described as &quot;bonds&quot;) but have a fixed volume because the strong forces between their filled electron shells repelling each other prevent the atoms packing together any more closely. This second effect is very similar to the force stopping you hand penetrating your desk.
Arguably this is all electronic interactions.
But, if you are a chemist, it is worth drawing a line because it makes it much easier to talk about the properties of molecules. Electronic interactions to a chemist are usually interactions transmitted via bonds in a molecule.
So a molecule like fluorescein (shown below) has an extended pi-system so the oxygens at either end of the three fused rings can interact via bonds (and the overall molecule has electronic transitions that make it a useful fluorescent dye).

But in a molecule like this substituted biphenyl the electronic interactions might drive the molecule to be planar (so the two pi-systems can communicate) but the steric size of the 4 methyl groups prevent that because the methyl groups would come too close in 3D space to allow a planar configuration.

So the molecule will not have two aromatic rings in the same plane but will have significant angles between the rings. A &quot;space filling&quot; view (below) shows the methyl groups take up too much space to allow the rings to be coplanar.

Chemists think of the forces trying to make this molecule planar as &quot;electronic&quot; as they are transmitted via the bonds but the forces preventing this as being &quot;steric&quot; interactions. They are more like the forces preventing your hand from penetrating your desk than they are alike the forces holding the molecule together.
It is a useful distinction even when the forces are internal to a molecule.