Question

(a) Below on the left are given the pi MOs for trans-1, 3, 5-hexatriene, in its doubly s-trans conformation (those are the top lobes of p AO's). First, occupy these six MOs on the left with the appropriate number of electrons by drawing them on the lines for the occupied MOs. Then, sketch in the pi MOs for the doubly s-cis conformation (middle) and then for the cis diastereomer in its doubly s-trans conformation (right) by drawing circles on each structure and shading them appropriately. Finally, draw a line for each MO you sketched, indicating whether that orbital is higher or lower in energy than the original MO in hexatriene (appropriately occupy these MOs as well).

Answer 1

讆 LUMO electron filled up

Pi MO'S Pi MO'S Pi MO'S Pi MO'S of hexatriene pi MO's of this Cis 1,3,5-hexatriene orbital is lower in energy than pi MO's of doubly -s-Cis 1,3,5- hexatriene again pi MO's of trans 1,3,5-hexatrene orbital are much more lower in energy than doubly-s-Cis 1,3,5 hexatrienea and Cis 1,3,5-hexatriene orbital orbital eergy