Research Article

Koopmans' Analysis of Chemical Hardness with Spectral-Like Resolution

Table 2

Molecular structures of paradigmatic aromatic hydrocarbons [66], ordered downwards according with their Hückel first-order HOMO-LUMO gap [69], along their first three highest occupied (HOMOs) and lowest unoccupied (LUMOs) (in electron-volts (eV)) computationally recorded levels within semiempirical AM1 method [68].

Formula
Name
CAS
Index (mw [g/mol])
Molecular
Structure
HOMO(1)HOMO(2)HOMO(3)LUMO(1)LUMO(2)LUMO(3)

C6H6
Benzene
71-43-2
I (78.11)
348415.table.002a−9.652904−9.653568−11.8874570.5548350.5552462.978299

C4H4N2
Pyrimidine
289-95-2
II (80.088)
348415.table.002b−10.578436−10.614932−11.602985−0.234993−0.0814212.543489

C5H5N
Pyridine
110-86-1
III (79.10)
348415.table.002c−9.932324−10.642881−10.7163730.1387050.2782732.791518

C6H6O
Phenol
108-95-2
IV (94.11)
348415.table.002d−9.114937−9.851116−11.9402660.3975170.5079862.839472

C6H7N
Aniline
62-53-3
V (93.13)
348415.table.002e−8.213677−9.550989−11.5016200.7584360.8889212.828224

C10H8
Naphthalene
91-20-3
VI (128.17)
348415.table.002f−8.710653−9.340973−10.658237−0.2656490.1806181.210350

C10H8O
2-Naphthol
135-19-3
VII (144.17)
348415.table.002g−8.641139−9.194596−10.673578−0.3484900.1417281.117961

C10H8O
1-Naphthol
90-15-3
VIII (144.17)
348415.table.002h−8.455599−9.454717−10.294406−0.2471710.1006441.184179

C10H9N
2-Naphthalenamine
91-59-8
IX (143.19)
348415.table.002i−8.230714−8.984826−10.346699−0.1777220.2787851.298534

C10H9N
1-Naphthalenamine
134-32-7
X (143.19)
348415.table.002j−8.109827−9.343444−9.940875−0.1763310.2304241.235745