What is the longest-wavelength electronic transition in each of the following species? Use molecular-orbital designations such as n → π*, π₁→π₂, in your answer. (Prepare a molecular-orbital energy diagram, like that in Figure 14-16, for each.) 

(a) 2-Propenyl (allyl) cation; 

(b) 2-propenyl (allyl) radical; 

(c) formaldehyde, H₂C=O; 

(d) N₂; 

(e) pentadienyl anion;

(f) 1,3,5-hexatriene.

Figure 14-16

Transcribed Image Text:

LUMO LUMO 7T hv * LUMO НОМО hv hv T2 НОМО НОМО E Decreasing HOMO-LUMO gap H,C=CH2 нн C-C `CH2 H Ethene H,C 2-Propenyl CH2 H,C 1,3-Butadiene radical