Multiwfn forum / Hirshfeld Surface Analysis of Zwitterionic Forms in a Schiff Base

Re: Hirshfeld Surface Analysis of Zwitterionic Forms in a Schiff Base

dummy@example.com (may01dz) — Mon, 21 Jul 2025 21:47:30 +0000

Thank you very much for your helpful and detailed response. I truly appreciate your guidance and the references you shared. I plan to follow your advice and will proceed with the IRI analysis in Multiwfn to investigate the presence of the intramolecular hydrogen bond and assess the zwitterionic nature of the molecule.

Re: Hirshfeld Surface Analysis of Zwitterionic Forms in a Schiff Base

dummy@example.com (sobereva) — Mon, 21 Jul 2025 21:33:14 +0000

Hirshfeld surface analysis is not directly relevant to determining presence of zwitterionic forms, you should simply visually check the structure.

To determine if there is an intramolecular H-bond, I suggest using the IRI analysis in Multiwfn, see illustrative example in original paper of IRI: Chemistry-Methods, 1, 231-239 (2021) DOI: 10.1002/cmtd.202100007
and my relevant reviews:
Tian Lu and Qinxue Chen, Visualization Analysis of Weak Interactions in Chemical Systems. In Comprehensive Computational Chemistry, vol. 2, pp. 240-264. Oxford: Elsevier (2024) DOI: 10.1016/B978-0-12-821978-2.00076-3
Tian Lu, Visualization Analysis of Covalent and Noncovalent Interactions in Real Space, Angew. Chem. Int. Ed., e202504895 (2025) DOI: 10.1002/anie.202504895

Hirshfeld Surface Analysis of Zwitterionic Forms in a Schiff Base

dummy@example.com (may01dz) — Mon, 21 Jul 2025 16:18:35 +0000

Hello,

I would like to use Hirshfeld surface analysis in Multiwfn to help confirm or rule out the presence of zwitterionic forms in a Schiff base molecule (see attached image). Specifically, I aim to determine whether an intramolecular N⁺−H⋯O⁻ hydrogen bond exists, which would support the zwitterionic character of the compound.