caa a22 4500 605510865 CHVBK 20210128100648.0 cr unu---uuuuu 210128e20150601xx s 000 0 eng 10.1007/s00894-015-2709-y doi (NATIONALLICENCE)springer-10.1007/s00894-015-2709-y Structural-topological preferences and protonation sequence of aliphatic polyamines: a theoretical case study of tetramine trien [Elektronische Daten] [Adedapo Adeyinka, Ignacy Cukrowski] A large set of lowest and medium energy conformers of aliphatic tetramine trien was used to uncover structural-topological preferences of poliamines. Numerous common structural features among HL and H 2 L tautomers were identified, e.g., H-atoms of protonated functional groups are always involved in intramolecular NH•••N interactions and they result in as large and as many as possible rings in lowest energy conformers. Largest, 11-membered, molecular rings stabilize a molecule most and they appeared to be strain free whereas 5-memebred intramolecular rings were most strained (all formed due to NH•••N interactions). The CH•••HC interactions with QTAIM-defined atomic interaction lines were also found but, surprisingly, mainly in the lowest energy conformers of HL tautomers. According to the non-covalent interaction-based (NCI) analysis, 5-memebered rings formed by CH•••HC interactions are not strained and, in general, 3D NCI isosurfaces mimic those obtained for weaker NH•••N interactions. Also, 3D NCI isosurfaces found for NH•••N and CH•••HC interactions, regardless whether linked or not by an atomic interaction line, appeared to be indistinguishable. Using lowest energy conformers, theoretically predicted mixture of primary (HL p ) and secondary (HL s ) forms of trien was found to be in accord with the literature reports; using linear conformers resulted in predicting HL s as the only tautomer formed. In contrast to HF, the overall performance of B3LYP was found satisfactory for the purpose of the study. Springer-Verlag Berlin Heidelberg, 2015 DFT nationallicence Linear aliphatic polyamines nationallicence Linear polyamines nationallicence NCI nationallicence Protonation sequence nationallicence QTAIM nationallicence Structural preferences nationallicence Topological preferences nationallicence Trien nationallicence Adeyinka Adedapo Department of Chemistry, Faculty of Natural and Agricultural Sciences, University of Pretoria, Lynnwood Road, 0002, Hatfield, Pretoria, South Africa aut Cukrowski Ignacy Department of Chemistry, Faculty of Natural and Agricultural Sciences, University of Pretoria, Lynnwood Road, 0002, Hatfield, Pretoria, South Africa aut Journal of Molecular Modeling Springer Berlin Heidelberg 21/6(2015-06-01), 1-18 1610-2940 21:6<1 2015 21 894 https://doi.org/10.1007/s00894-015-2709-y text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00894-015-2709-y text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Adeyinka Adedapo Department of Chemistry, Faculty of Natural and Agricultural Sciences, University of Pretoria, Lynnwood Road, 0002, Hatfield, Pretoria, South Africa aut NATIONALLICENCE 700 1- Cukrowski Ignacy Department of Chemistry, Faculty of Natural and Agricultural Sciences, University of Pretoria, Lynnwood Road, 0002, Hatfield, Pretoria, South Africa aut NATIONALLICENCE 773 0- Journal of Molecular Modeling Springer Berlin Heidelberg 21/6(2015-06-01), 1-18 1610-2940 21:6<1 2015 21 894