Work

Mending Ties with Halogens. HALO–DP4+: An Approach for DP4+ Calculations in Organohalogenated Molecules

Year: 2025

Type: article

Abstract: The combined use of NMR spectroscopy and quantum chemical calculations has become a powerful strategy for structural elucidation. However, halogenated compounds pose a particular challenge due to the so-called HALA effect, where heavy atoms distort the shielding of nearby light atoms, often leading to misleading predictions. Although a common workaround is to discard affected signals, this approach fails in polyhalogenated systems, where too much valuable information is lost. In this study, we systematically explored a range of strategies to mitigate the HALA effect across different levels of theory and probability-based methods: DP4, MM-DP4+, and DP4+. This comprehensive analysis led us to develop HALO-DP4+, a simple yet robust correction protocol that significantly improves performance and can be universally applied regardless level of theory used. To streamline its use, we updated our DP4+App to fully automate the correction process, making HALO-DP4+ readily accessible for routine structure determination, even in challenging halogenated frameworks.

Source: The Journal of Organic Chemistry

DOI: 10.1021/acs.joc.5c01979

Authors: Lucas Passaglia, Bruno A. Franco, María M. Zanardi, Ariel M. Sarotti

Institutions: Consejo Nacional de Investigaciones Científicas y Técnicas, Pontificia Universidad Católica Argentina, National University of Rosario

Language: English

Topic: Molecular spectroscopy and chirality

Subfield: Spectroscopy

Field: Chemistry

Domain: Physical Sciences

Open Access status: green

Funders: Consejo Nacional de Investigaciones Científicas y Técnicas, Agencia Nacional de Promoción Científica y Tecnológica

Awards: G2439223879, G395359323, G4439121747, G555897400