the five lowest energy conformers—a phenomenon that was also observed for
monomeric naphthylisoquinoline alkaloids with antimalarial activity [16] and for
michellamine A [12]. For higher energy conformers, the electron distribution
becomes considerably different for the two naphthalene moieties. For conformers of
S/S′ symmetric pairs, electrons concentrate on one or the other of the naphthalene
moieties.
3.3 Results in Solution
Table 2 shows the relative energy of the conformers in the three solvents considered (chloroform, acetonitrile and water). The relative energy of the conformer
decreases with increasing solvent polarity—which is consistent with common
behaviours. (Acetonitrile has a greater dipole moment than water, but its effect on
solutes is often intermediate between that of chloroform and that of water; therefore,
“increasing solvent polarities” refers to the chloroform-acetonitrile-water sequence
HOMO
a-b-e-f-g-h-p-v-x
a-b-e-f-g-h-q-v-x
a-b-e-f- g-h-q-t-x
a-b-e-f-g-h-q-v-y
a-b-e-f-g-h-p-t-x
a-b-f-h-q-v-x
a-b-e-g-q-t-x
b-c-e-f-g-h- q-t-x
b-c-q-t-x
a-d-q-t-x
LUMO
a-b-e-f-g-h-p-v-x
a-b-e-f-g-h-q-v-x
a-b-e-f-g-h-q-t-x
a-b-e-f-g-h-q-v-y
a-b-e-f-g-h-p-t-x
a-b-f-h-q-v-x
b-c-e-f-g-h- q-t-x
a-b-e-g-q-t-x
b-c-q-t-x
a-d-q-t-x
Fig. 6 Shapes of the HOMO and LUMO frontier orbitals of the lowest energy conformers of
jozimine A 2 . HF/6-31G(d,p) results. The initial part of the acronyms is not reported under the
images, because of space reasons; it is the same for all the conformers (JZM)
322
M. K. Bilonda and L. Mammino
monomeric naphthylisoquinoline alkaloids with antimalarial activity [16] and for
michellamine A [12]. For higher energy conformers, the electron distribution
becomes considerably different for the two naphthalene moieties. For conformers of
S/S′ symmetric pairs, electrons concentrate on one or the other of the naphthalene
moieties.
3.3 Results in Solution
Table 2 shows the relative energy of the conformers in the three solvents considered (chloroform, acetonitrile and water). The relative energy of the conformer
decreases with increasing solvent polarity—which is consistent with common
behaviours. (Acetonitrile has a greater dipole moment than water, but its effect on
solutes is often intermediate between that of chloroform and that of water; therefore,
“increasing solvent polarities” refers to the chloroform-acetonitrile-water sequence
HOMO
a-b-e-f-g-h-p-v-x
a-b-e-f-g-h-q-v-x
a-b-e-f- g-h-q-t-x
a-b-e-f-g-h-q-v-y
a-b-e-f-g-h-p-t-x
a-b-f-h-q-v-x
a-b-e-g-q-t-x
b-c-e-f-g-h- q-t-x
b-c-q-t-x
a-d-q-t-x
LUMO
a-b-e-f-g-h-p-v-x
a-b-e-f-g-h-q-v-x
a-b-e-f-g-h-q-t-x
a-b-e-f-g-h-q-v-y
a-b-e-f-g-h-p-t-x
a-b-f-h-q-v-x
b-c-e-f-g-h- q-t-x
a-b-e-g-q-t-x
b-c-q-t-x
a-d-q-t-x
Fig. 6 Shapes of the HOMO and LUMO frontier orbitals of the lowest energy conformers of
jozimine A 2 . HF/6-31G(d,p) results. The initial part of the acronyms is not reported under the
images, because of space reasons; it is the same for all the conformers (JZM)
322
M. K. Bilonda and L. Mammino