Guanine tautomers

Marian CM (2007) The guanine tautomer puzzle quantum chemical investigation of ground and... [Pg.334]

TABLE XVIB Electronic Properties of Guanine Tautomers (CNDO Method) ... [Pg.139]

Figure 13 presents the distribution of electronic charges, as evaluated by the CNDO/2 method in the most significant guanine tautomers. [Pg.140]

Fig. 13. Net electronic charges in guanine tautomers evaluated by the CNDO/2 method. Upper numbers a charges lower numbers tt charges.

An interesting feature of the gas-phase guanine tautomers is that their amino group is nonplanar. The sum of the angles about the amine nitrogen is less than 348° for the tautomers 14a-i, and specifically 340.4° and 337.4° in 14a and 14b, respectively. This is more pyramidal than for any of the other nucleic acid bases. [Pg.474]

TABLE 7.14 Relative Energies (in kcal moi of Guanine Tautomers (14a-j)... [Pg.475]

Figure 7.12 Structures of mono- and dihydrated guanine tautomers 14a-c. ...

Figure 4. Structure of guanine tautomers (a) geometry of the keto-N9H tautomer in the Si(7C7C ) state, (b) hydrated form of keto-N9H tautomer in the ground state (top indices) and Si(7CJt ) state (bottom indices) (c) hydrated form of keto-N7H tautomer in the ground state (top indices) and Si(jui ) state (bottom indices).

Figure 5. Energy level diagrams of guanine tautomers, (A) isolated form (B) hydrated form. In the ease of isolated tautom s, (a),... [Pg.289]

P.G. Mezey and J.J. Ladik, A non-empirical molecular orbital study on the relative stabilities of adenine and guanine tautomers, Theor. Chim. Acta 52 (1979), pp. 129-145. [Pg.153]

Fie 1 a-h- IR frequencies for the eight lowest eneigy guanine tautomers, as calculated by Marian r-iTn j, -s uown in the structures on the fr/t. Color coding of the structures is... [Pg.275]

Selected values of torsional angles MP2/6-31G(d) level. of 7-guanine tautomers calculated at the... [Pg.189]

Relative stability (Kcal-mol ) and dipole moments (D) of guanine tautomers and their mono- ... [Pg.196]

Marian, C. M. (2007). The guanine tautomer puzzle Quantum chemical investigation of ground and excited states. The Journal of Physical Chemistry A, 111, 1545. [Pg.1273]

Zhou, J., Kostko, O., Nicolas, C., Tang, X., Belau, L., de Vries, M. S., 8c Ahmed, M. (2009). Experimental observation of guanine tautomers with VUV photoionization. The Journal of Physical Chemistry A, 113, 4829. [Pg.1275]

Orientation and size of the isolated NA bases (a) guanine, (b) N7 protonated guanine tautomer, (c) adenine, (d) cytosine, (e) thymine, (f) uracil. Standard atom numbering is used (e.g., textbook of Saenger 1983)... [Pg.1282]

The rotational constants and dipole moments of the normal tautomer of adenine and four lower-energy tautomeric forms of guanine are presented in Tables 6 and 7. While the calculated data are in good agreement with available experimental parameters for adenine, the experimental data for guanine tautomers are not accessible. On the basis of a comparison of the DFT, MP2, and experimental rotational constants for all other NABs, similar accuracy is expected for the predicted parameters of the guanine tautomers. [Pg.2955]

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