AbstractThe He I and He II photoelectron spectra of 4‐methylmorpholine, 4‐morpholinecarbonitrile, and 4‐morpholinepropionitrile have been measured. The electronic structure and heteroatom lone pair interactions, in particular, were analyzed with the aid of HeII/HeI intensity variations, comparison with the spectra of related compounds, and AM1 semiempirical calculations. We present an example of combined inductive and resonance interactions operating in the morpholine ring s