5.7 Experimental Section
153
Fig. 5.26 Energy levels and frontier orbitals of tetramer structures of 3G/MeOH (a LUMO,
c HOMO) and 3O scsc (b LUMO, d HOMO). All the H atoms are omitted for clarity
5.7.13 Analysis of Polarity in Crystals 3G/MeOH and 3O scsc
All molecules in the crystals exhibit a dipole moment (blue arrows in Fig. 5.27a,
b, d, and e). When these molecules crystallize to form 3G/MeOH with polar space
group that does not contain an inversion center, the tetramer units in these crystals
also exhibit a dipole moment (Fig. 5.27). Conversely, the dimer units in crystals of
3O scsc , which crystallize in a space group with an inversion center, do not exhibit a
dipole moment (Fig. 5.27).