### Abstract

The hydrogen-bond interaction of 4-hydroxypyridine and 3-hydroxypyridine with H_{2}O is investigated with the use of a combined experimental matrix-isolation FT-IR and theoretical ab-initio method. Both of these isomeric compounds occur in the hydroxy form in low-temperature Ar matrices, in accordance with the predicted stability difference from the oxo form of 22 and 55 kJ/mol for 4-hydroxypyridine and 3-hydroxypyridine, respectively. The most stable H-bonded complex of the hydroxy tautomers of both compounds with water is the O-H⋯OH_{2} structure, and the stability differences with the nearest lying isomeric N⋯HO-H structures are 6.74 and 6.41 kJ/mol, respectively. Both complexes are identified with the use of the predicted frequency perturbations. The correlation between the predicted interaction energies and the frequency shifts of the modes of bonded water and the scaling factors of these modes is analyzed for the series pyrimidine, pyridine, 3-hydroxypyridine, 4-hydroxypyridine, and 4-aminopyridine. The relative basicity and acidity of 4-hydroxypyridine and 3-hydroxypyridine are estimated from this analysis and discussed.

Original language | English (US) |
---|---|

Pages (from-to) | 14967-14979 |

Number of pages | 13 |

Journal | Journal of Physical Chemistry |

Volume | 99 |

Issue number | 41 |

State | Published - 1995 |

### Fingerprint

### ASJC Scopus subject areas

- Physical and Theoretical Chemistry

### Cite this

_{2}O in Ar matrices.

*Journal of Physical Chemistry*,

*99*(41), 14967-14979.

**Matrix-isolation FT-IR studies and ab-initio calculations of hydrogen-bonded complexes of molecules modeling cytosine or isocytosine tautomers. 3. Complexes of 4-hydroxypyridine and 3-hydroxypyridine with H _{2}O in Ar matrices.** / Buyl, Fritz; Smets, Johan; Maes, Guido; Adamowicz, Ludwik.

Research output: Contribution to journal › Article

_{2}O in Ar matrices',

*Journal of Physical Chemistry*, vol. 99, no. 41, pp. 14967-14979.

_{2}O in Ar matrices. Journal of Physical Chemistry. 1995;99(41):14967-14979.

}

TY - JOUR

T1 - Matrix-isolation FT-IR studies and ab-initio calculations of hydrogen-bonded complexes of molecules modeling cytosine or isocytosine tautomers. 3. Complexes of 4-hydroxypyridine and 3-hydroxypyridine with H2O in Ar matrices

AU - Buyl, Fritz

AU - Smets, Johan

AU - Maes, Guido

AU - Adamowicz, Ludwik

PY - 1995

Y1 - 1995

N2 - The hydrogen-bond interaction of 4-hydroxypyridine and 3-hydroxypyridine with H2O is investigated with the use of a combined experimental matrix-isolation FT-IR and theoretical ab-initio method. Both of these isomeric compounds occur in the hydroxy form in low-temperature Ar matrices, in accordance with the predicted stability difference from the oxo form of 22 and 55 kJ/mol for 4-hydroxypyridine and 3-hydroxypyridine, respectively. The most stable H-bonded complex of the hydroxy tautomers of both compounds with water is the O-H⋯OH2 structure, and the stability differences with the nearest lying isomeric N⋯HO-H structures are 6.74 and 6.41 kJ/mol, respectively. Both complexes are identified with the use of the predicted frequency perturbations. The correlation between the predicted interaction energies and the frequency shifts of the modes of bonded water and the scaling factors of these modes is analyzed for the series pyrimidine, pyridine, 3-hydroxypyridine, 4-hydroxypyridine, and 4-aminopyridine. The relative basicity and acidity of 4-hydroxypyridine and 3-hydroxypyridine are estimated from this analysis and discussed.

AB - The hydrogen-bond interaction of 4-hydroxypyridine and 3-hydroxypyridine with H2O is investigated with the use of a combined experimental matrix-isolation FT-IR and theoretical ab-initio method. Both of these isomeric compounds occur in the hydroxy form in low-temperature Ar matrices, in accordance with the predicted stability difference from the oxo form of 22 and 55 kJ/mol for 4-hydroxypyridine and 3-hydroxypyridine, respectively. The most stable H-bonded complex of the hydroxy tautomers of both compounds with water is the O-H⋯OH2 structure, and the stability differences with the nearest lying isomeric N⋯HO-H structures are 6.74 and 6.41 kJ/mol, respectively. Both complexes are identified with the use of the predicted frequency perturbations. The correlation between the predicted interaction energies and the frequency shifts of the modes of bonded water and the scaling factors of these modes is analyzed for the series pyrimidine, pyridine, 3-hydroxypyridine, 4-hydroxypyridine, and 4-aminopyridine. The relative basicity and acidity of 4-hydroxypyridine and 3-hydroxypyridine are estimated from this analysis and discussed.

UR - http://www.scopus.com/inward/record.url?scp=33751156709&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33751156709&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:33751156709

VL - 99

SP - 14967

EP - 14979

JO - Journal of Physical Chemistry

JF - Journal of Physical Chemistry

SN - 0022-3654

IS - 41

ER -