Comparative study of structure and photo-induced reactivity of malonaldehyde and acetylacetone isolated in nitrogen matrices

• Veröffentlicht in: Физика низких температур
• Datum: 2006
• ISSN: 0132-6414
• Hauptverfasser: Trivella, A., Coussan, S., Chiavassa, T., Theule, P., Manca, C., Roubin, P.
• Format: Artikel
• Sprache: Englisch
• Veröffentlicht: Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України 2006
• Schlagworte: Molecular Solids
• Online Zugang: https://nasplib.isofts.kiev.ua/handle/123456789/120884
• Назва журналу: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Zitieren: Comparative study of structure and photo-induced
 reactivity of malonaldehyde and acetylacetone isolated
 in nitrogen matrices / A. Trivella, S. Coussan, T. Chiavassa, P. Theule, C. Manca, P. Roubin // Физика низких температур. — 2006. — Т. 32, № 11. — С. 1372–1381. — Бібліогр.: 59 назв. — англ.

Structure and reactivity of the eight enolic forms (one chelated and seven non-chelated) of
 malonaldehyde and acetylacetone are compared through theoretical and experimental data.
 Ground-state geometries, energies, and vibrational frequencies are calculated with the
 B3LYP/6–311++G(2d,2p) model chemistry. The electronic delocalisation as well as the
 cis/trans rotamer properties are analysed. The hydrogen bond strength of the chelated forms can
 be estimated by the energy difference between chelated and non-chelated forms, and its enhancement
 due to methyl-induced electron release is estimated at 1.7 kcal·mol⁻¹. UV- and
 IR-induced reactivity of molecules isolated in nitrogen matrices is studied by means of FT–IR
 spectrometry. Interconversion between rotamers is the main process observed for both molecules,
 only some among the seven non-chelated forms being created.