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Titolo:
Tautomerization of nucleobase model compounds: The 4-pyridinol and 4(1H)-pyridinone monomers and their dimers
Autore:
Reimers, JR; Hall, LE; Hush, NS;
Indirizzi:
Univ Sydney, Sch Chem, Sydney, NSW 2006, Australia Univ Sydney Sydney NSWAustralia 2006 h Chem, Sydney, NSW 2006, Australia Univ Sydney, Dept Biochem, Sydney, NSW 2006, Australia Univ Sydney SydneyNSW Australia 2006 iochem, Sydney, NSW 2006, Australia
Titolo Testata:
JOURNAL OF PHYSICAL CHEMISTRY A
fascicolo: 21, volume: 104, anno: 2000,
pagine: 5087 - 5092
SICI:
1089-5639(20000601)104:21<5087:TONMCT>2.0.ZU;2-P
Fonte:
ISI
Lingua:
ENG
Soggetto:
HYDROGEN-BONDED COMPLEXES; ISOLATION FT-IR; AB-INITIO; PROTOMERIC EQUILIBRIA; ELECTRON CORRELATION; AQUEOUS-SOLUTION; GAS-PHASE; WATER; MOLECULES; ABINITIO;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
49
Recensione:
Indirizzi per estratti:
Indirizzo: Reimers, JR Univ Sydney, Sch Chem, Sydney, NSW 2006, Australia Univ Sydney Sydney NSW Australia 2006 ey, NSW 2006, Australia
Citazione:
J.R. Reimers et al., "Tautomerization of nucleobase model compounds: The 4-pyridinol and 4(1H)-pyridinone monomers and their dimers", J PHYS CH A, 104(21), 2000, pp. 5087-5092

Abstract

Nucleobases are important in many biochemical pathways, and one of their key features is that low-energy tautomerization processes can cause large changes in their chemical properties. Similar effects are also seen for photovoltaic molecules such as quinacridones, except that, in these systems, tautomerization is achieved through intermolecular proton transfer. An excellent model for both of these systems is the tautomerization between the 4-pyridinol and 4(1H)-pyridinone monomers and their dimers. Indeed, 4-pyridinol is known to be the most stable monomer in the gas phase, while chemically diverse 4(1H)-pyridinone is the most stable monomer both neat and in solution in polar solvents. We evaluate the energetics of gas-phase tautomerization of both monomers and dimers of these molecules using B3LYP, HCTH, SCF, MP2, MP4, QCISD, CCSD, and CCSD(T) methodologies. For the monomers, estimatesof the CCSD(T)/aug-cc-pVTZ energies are obtained, while for the dimers, estimates of basis-set-superposition-error-corrected CCSD/aug-cc-pVDZ energies are obtained. Vibrational analyses are performed at the B3LYP/cc-pVDZ level to determine zero-point energy corrections and OH- and NH-stretch vibrational frequency changes. The hydrogen-bond energies show a clear preferencefor 4(1H)-pyridinone-containing dimers, and the dimer in which 4-pyridinoldonates a hydrogen bond to 4(1H)-pyridinone is calculated to be only slightly higher in energy than the 4-pyridinol dimer.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 02/12/20 alle ore 14:46:52