[webassignbuddy]

"Looking at diagram B and D, the letter that corresponds to the best and lowest energy representation of the electron flow for the imine formation would be B."

Why? I thought the answer would be D because oxygen is more electronegative than N.

[Babcock_Hall]

I would think about basicity.

[webassignbuddy]

I would think about basicity.

They're both sp3 hybridized, so it's hard to compare basicity.

[zsinger]

Hybridization is not the only A/B consideration when rationalizing strength/weakness .

[webassignbuddy]

Hybridization is not the only A/B consideration when rationalizing strength/weakness .

Then what is it then because I'm utterly confused? 

[Babcock_Hall]

Have you tried comparing the two bases by finding the pK_a values of the corresponding conjugate acids?

[webassignbuddy]

Have you tried comparing the two bases by finding the pK_a values of the corresponding conjugate acids?

But this was on a test. we weren't given the pKa values

[Babcock_Hall]

I am not overly fond of arguments invoking electronegativity.  However, in this case we might use electronegativity to explain why oxygen is less willing to bear a positive charge than is nitrogen.