Fig. 2

Optimized (B3LYP/6–311 + + G(d,p)) geometry of the UDMA model (C1H2-C2H2 and C3H2-C4H2 groups are in anti and gauche conformational states, respectively).

Optimized (B3LYP/6–311 + + G(d,p)) geometry of the UDMA model (C1H2-C2H2 and C3H2-C4H2 groups are in anti and gauche conformational states, respectively).