Question

Question #43102

Answer 1

Perhaps they do, but they are constrained in different geometries and orientations.....

Explanation:

The modern covalent bond is conceived to be a region of high electron density between 2 positively charged nuclei, such that internuclear repulsion is NEGATED, and a net attractive force between the nuclei and the electron cloud results. The equilibrium distance minimizes internuclear repulsion, and maximizes electron-cloud/nucleus attraction, and this distance is the equilibrium bond length.

A single bond localizes electron density between the nuclei.

And a double bond localizes electron density above and below the plane of the atom-atom vector, and given Cartesian geometry, 2 axes are possible for this overlap, as the diagram shows.....

For the 2 `pi` bonds, there is little electron density between the atom-atom vector.

Quadruple bonding, so-called `delta-"bonding"`, is conceivable (i.e. a bond with 3 nodal planes), but rarely can be invoked.