829523.fig.002a
(a)
829523.fig.002b
(b)
829523.fig.002c
(c)
Figure 2: Potential energy surface of the side chain of [DEME]+ as a function of (a) CN+CC, (b) N+COO, and (c) CCOC dihedral angles. Here, two CCN+C angles for the ethyl-group of [DEME]+ are fixed at 180°, whose angle corresponds to form.