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. 2018 Apr 10;8(24):13433–13445. doi: 10.1039/c8ra01446a

Energetic (in kcal mol−1) and kinetic (in s) characteristics of the tautomerization of the classical A·T DNA base pairs into the wobble base mispairs via the sequential PT followed by DPT obtained at the MP2/aug-cc-pVDZ//B3LYP/6-311++G(d,p) level of QM theory in the continuum with ε = 1 under normal conditions (see Fig. 1).

Tautomeric transition ν i a ΔGb ΔEc ΔΔGTSd ΔΔETSe ΔΔGf ΔΔEg τ 99.9% h τ i P j
graphic file with name c8ra01446a-t18.jpg 66.5 27.71 29.12 32.86 32.49 5.15 3.37 6.62 × 10−9 9.58 × 10−10 4.72 × 10−21
graphic file with name c8ra01446a-t19.jpg 137.7 28.92 29.23 27.43 29.29 −1.49 0.06 8.83 × 10−14 1.28 × 10−14 2.91 × 10−42
A·T(rWC) ↔ A·T*(rwWC) 132.4 18.56 17.69 26.84 25.43 8.29 7.74 1.31 × 10−6 1.90 × 10−7 2.45 × 10−14
A·T*(rwWC) ↔ A*·T(rwWC) 906.3 1.61 1.24 3.00 5.08 1.39 3.85 1.08 × 10−11 1.67 × 10−12 1.60 × 10−15
A·T(H) ↔ A·T*(wH) 155.3 21.92 22.94 31.91 31.69 9.99 8.75 2.31 × 10−5 3.35 × 10−6 8.39 × 10−17
graphic file with name c8ra01446a-t20.jpg 1136.0 18.95 17.97 18.99 20.81 0.04 2.84 5.56 × 10−13 8.04 × 10−14 1.06 × 10−30
graphic file with name c8ra01446a-t21.jpg 147.1 22.68 22.44 32.46 31.63 9.78 9.19 1.62 × 10−5 2.34 × 10−6 2.32 × 10−17
graphic file with name c8ra01446a-t22.jpg 797.1 12.87 12.96 10.90 13.14 −1.97 0.18 2.54 × 10−14 3.68 × 10−15 8.45 × 10−27
graphic file with name c8ra01446a-t23.jpg 134.0 25.66 26.83 33.03 32.94 7.38 6.11 2.81 × 10−7 4.07 × 10−8 1.52 × 10−19
graphic file with name c8ra01446a-t24.jpg 1129.2 15.49 14.51 16.09 17.76 0.60 3.25 1.43 × 10−12 2.08 × 10−13 6.61 × 10−31
A·T(rH) ↔ A·T*(rwH) 159.0 18.99 18.42 31.15 30.53 12.17 12.11 9.13 × 10−4 1.32 × 10−4 1.18 × 10−14
graphic file with name c8ra01446a-t25.jpg 727.4 15.34 15.73 13.36 15.73 −1.98 0.01 3.86 × 10−14 5.58 × 10−15 6.65 × 10−26
a

The imaginary frequency at the TS of the tautomeric transition, cm−1.

b

The Gibbs free energy of the product relatively the reactant of the tautomeric transition (T = 298.15 K).

c

The electronic energy of the product relatively the reactant of the tautomeric transition.

d

The Gibbs free energy barrier for the forward tautomeric transition.

e

The electronic energy barrier for the forward tautomeric transition.

f

The Gibbs free energy barrier for the reverse tautomeric transition.

g

The electronic energy barrier for the reverse tautomeric transition.

h

The time necessary to reach 99.9% of the equilibrium concentration between the reactant and the product of the tautomerisation reaction, s.

i

The lifetime of the product of the tautomerisation reaction, s.

j

The thermal population of the tautomerised structures, which is situated on the right in the first row of the table.