I have the reaction below and am asked to determine the HOMO and LUMO of the two reactants. I know that the cyanide anion will be the nucleophile since it is donating an electron pair to the formaldehyde, which will be the electrophile. However, is there a way (without drawing the molecular orbital diagram) to determine which bond in each reactant will be the HOMO and the LUMO?

And also, if a lone pair is present in a compound will that always be the HOMO?

Thank you!

enter image description here

  • 1
    $\begingroup$ If it's a bond, it can't be the LUMO (the U stands for unoccupied). $\endgroup$ – Karsten Theis May 23 '19 at 17:46

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.