570394.fig.001a
(a)
570394.fig.001b
(b)
570394.fig.001c
(c)
Figure 1: Optimized structures of different trimethylene glycol conformations such as (a) TMG-1, (b) TMG-2, and (c) TMG-3 using WB97XD/6-31++G(d,p) (colour legend: red = oxygen, black = carbon, and whitish grey = hydrogen, and black dotted line is hydrogen bond and hydrogen bond distance in Å).