Gas-phase tautomeric equilibrium of 4-hydroxypyrimidine with its ketonic forms: a free jet millimeterwave spectroscopy study.
4-Hydroxypyrimidine (4HP) has two conformational forms (the hydroxyl hydrogen cis or trans with respect to the adjacent nitrogen), which are in tautomeric equilibrium with two ketonic forms, 4-pyrimidinone (4PO) and 6-pyrimidinone (6PO). We have investigated the free jet absorption millimeterwave spectrum of this system, assigning the rotational spectra of 4HPcis and 4PO; the latter species is more stable by 2.0(9) kJ/mol. No lines corresponding to the trans isomer of 4-hydroxypyridine and to 6PO have been observed.
Sanchez
Raquel
R
Dipartimento di Chimica "G. Ciamician" dell'Università, Via Selmi 2, I-40126 Bologna, Italy.
Giuliano
B Michela
BM
Melandri
Sonia
S
Favero
Laura B
LB
Caminati
Walther
W
D005740:Gases; D007536:Isomerism; D007659:Ketones / Q000737:chemistry*; D008956:Models, Chemical; D015394:Molecular Structure; D011744:Pyrimidinones / Q000737:chemistry*; D013057:Spectrum Analysis
D005740:Gases; D007659:Ketones; D011744:Pyrimidinones; C108140:4-hydroxypyrimidine