70
3 Dopaquinone Conversion and Related Reactions
Fig. 3.19 Correlation between bond formation/activation energies for C6–N bond formation in the
cyclization and the corresponding HOMO energy levels of a dopaminequinone, b dopaquinone, c Nmethyl-dopaminequinone, and d N-formyl-dopaminequinone. Diamonds show activation energies
and square boxes show bond formation energies. The vacuum level was chosen as the origin of
energy level. The inset shows correlation between the bond formation energies and the activation
energies. Note that the bond formation/activation energies are defined for C6–N bond formation (an
elementary process) but not for the whole cyclization. Reprinted (with minor modification) from
Ref. [22] with permission from Wiley
Fig. 3.20 Isosurface plots for HOMOs of b dopaquinone and c N-methyl-dopaminequinone with
dotted lines for emphasizing anti-bonding orbital interaction (out-of-phase overlapping between
two wavefunctions) inside the hydrocarbon side chain (including amino group)
3 Dopaquinone Conversion and Related Reactions
Fig. 3.19 Correlation between bond formation/activation energies for C6–N bond formation in the
cyclization and the corresponding HOMO energy levels of a dopaminequinone, b dopaquinone, c Nmethyl-dopaminequinone, and d N-formyl-dopaminequinone. Diamonds show activation energies
and square boxes show bond formation energies. The vacuum level was chosen as the origin of
energy level. The inset shows correlation between the bond formation energies and the activation
energies. Note that the bond formation/activation energies are defined for C6–N bond formation (an
elementary process) but not for the whole cyclization. Reprinted (with minor modification) from
Ref. [22] with permission from Wiley
Fig. 3.20 Isosurface plots for HOMOs of b dopaquinone and c N-methyl-dopaminequinone with
dotted lines for emphasizing anti-bonding orbital interaction (out-of-phase overlapping between
two wavefunctions) inside the hydrocarbon side chain (including amino group)