Transverse Acoustic Modes of Biogenic and α,ω-Polyamines: A Study by Inelastic Neutron Scattering and Raman Spectroscopies Coupled to DFT Calculations

• Autor(a) principal: Carvalho, Luís A. E. Batista de
• Data de Publicação: 2006
• Outros Autores: Marques, M. Paula M., Tomkinson, John
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10316/10488; https://doi.org/10.1021/jp064837d
• topic: Algorithms; Biogenic Polyamines; Molecular Structure; Neutron Diffraction; Polyamines; Quantum Theory; Spectrum Analysis, Raman; Spermidine; Spermine

A complete analysis of the transverse acoustic modes (TAMs) for the homologous series of α,ω-diamines (H2N(CH2)nNH2) (n = 2−10, n = 12) as well as for the biogenic polyamines spermidine and spermine was undertaken, by Raman and inelastic neutron scattering (INS) spectroscopies combined with density functional theory (DFT) calculations. A complete assignment of the whole set of TAMs was carried out, for both the undeuterated and N-deuterated species. 1,2-Diaminoethane was found to display exceptional behavior, probably due to the formation of dimers in the solid state. An n-even/n-odd dependence of the low frequency INS pattern was observed for these polyamines. The very good accordance between their INS experimental TAMs and the ones previously reported for the corresponding n-alkanes suggest a close conformational similarity between these systems.