Protonation sequence of linear aliphatic polyamines from intramolecular atomic energies and charges

Structural-topological preferences and protonation sequence of aliphatic polyamines: a theoretical case study of tetramine trien.

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 ...

Determination of protonation constants of some fluorinated polyamines by means of 13C NMR data processed by the new computer program HypNMR2000. Protonation sequence in polyamines.

The p K(a) values of 6-fluoro-4,8-diazadodecane-1,12-diamine (6-fluorospermine) (1), 6,6-difluoro-4,8-diazadodecane-1,12-diamine (6,6-difluorospermine) (2), 6-fluoro-4-azaoctane-1,8-diamine (6-fluorospermidine) (3) and 6,6-difluoro-4-azaoctane-1,8-diamine (6,6-difluorospermidine) (4) in D(2)O solution have been determined at 40 degrees C from (13)C NMR chemical shifts data using the new compute...

on the effect of linear & non-linear texts on students comprehension and recalling

چکیده ندارد.

On the Relationship between Molecular Core Binding Energies and Atomic Charges

ONIOM-based QM:QM electronic embedding method using Löwdin atomic charges: energies and analytic gradients.

In this work, we report a new quantum mechanical:quantum mechanical (QM:QM) method which provides explicit electronic polarization of the high-level region by using the Löwdin atomic charges from the low-level region. This provides an embedding potential which naturally evolves with changes in nuclear geometry. However, this coupling of the high-level and low-level regions introduces complicati...