Table 2: Bond critical point parameters of intermolecular hydrogen bonds: electron density, Laplacian of the electron density, and hydrogen bond strength (kJ/mol) (calculated from B3LYP/6-311++G(d,p) wave function in gas phase) for anthraquinone and its derivatives.

SpeciesBCP parameters
(au) (au) (kJ/mol) (kJ/mol) (kJ/mol) (kJ/mol)

O6-H…O2
B20.04930.1483−3.342100.662−104.0030.9652.001
C20.04590.1412−1.06093.737−94.7970.9847.398
D20.04850.1464−2.79398.896−101.6900.9750.845
E20.04500.1381−0.69291.347−92.0390.9946.019
F20.04360.13470.00688.417−88.4101.0044.205
G20.04620.1416−1.19894.155−95.3530.9847.676
J20.04380.1343−0.228588.389−88.6170.9944.308
L20.04660.1417−1.60494.631−96.2360.9848.118
O10-H…O2
B20.04370.13540.022388.841−88.8191.0044.409
C20.04370.13570.00489.048−89.0431.0044.521
D20.04440.1374−0.265190.438−90.7030.9945.351
E20.04410.1360−0.209089.449−89.6580.9944.829
F20.04490.138−0.644891.163−91.8080.9945.904
G20.04350.13470.069088.337−88.26811.0044.135
J20.04390.1346−31.817288.694−89.01220.9944.506
L20.04660.1417−1.61194.648−96.26000.9848.130