Charge Anisotropy of Nitrogen : Where Chemical Intuition Fails

For more than half a century computer simulations were developed and employed to study ensemble properties of a wide variety of atomic and molecular systems with tremendous success. Nowadays, a selection of force-fields is available that describe the interactions in such systems. A key feature of force-fields is an adequate description of the electrostatic potential (ESP). Several force-fields model the ESP via point charges positioned at the atom centers. A major shortcoming of this approach, its inability to model anisotropies in the ESP, can be mitigated using additional charge sites. It has been shown that nitrogen is the most problematic element abundant in many polymers as well as large molecules of biological origin. To tackle this issue, small organic molecules containing a single nitrogen atom were studied. In performing rigorous scans of the surroundings of these nitrogen atoms, positions where a single extra charge can enhance the ESP description the most were identified. Significant improvements are found for ammonia, amines, and amides. Interestingly, the optimal location for the extra charge does not correlate with the chemically intuitive position of the nitrogen lone pair. In fact, the placement of an extra charge in the lone-pair location does not lead to significant improvements in most cases.

Medienart:

E-Artikel

Erscheinungsjahr:

2020

Erschienen:

2020

Enthalten in:

Zur Gesamtaufnahme - volume:16

Enthalten in:

Journal of chemical theory and computation - 16(2020), 7 vom: 14. Juli, Seite 4443-4453

Sprache:

Englisch

Beteiligte Personen:

Spinn, Alexander [VerfasserIn]
Handle, Philip H [VerfasserIn]
Kraml, Johannes [VerfasserIn]
Hofer, Thomas S [VerfasserIn]
Liedl, Klaus R [VerfasserIn]

Links:

Volltext

Themen:

Journal Article

Anmerkungen:

Date Completed 14.07.2020

Date Revised 11.11.2023

published: Print-Electronic

Citation Status PubMed-not-MEDLINE

doi:

10.1021/acs.jctc.0c00204

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM310099374