Incorporating Anionic Ligands in Chemical Space Exploration with New Ligand Additivity Relationships
Name
Kulik_JCIM_2025.pdf
Description
Accepted version
Size
3.76 MB
Format
Adobe PDF
Checksum (MD5)
6957ed3a8190d82298f34174ce992464
Author(s)
Kulik, Heather J
Date Issued
June 3, 2025
Journal
Journal of Chemical Information and Modeling
Publisher
American Chemical Society
Citation
Kulik, Heather J. 2025. "Incorporating Anionic Ligands in Chemical Space Exploration with New Ligand Additivity Relationships." Journal of Chemical Information and Modeling, 65 (12).
Version
Author's final manuscript
Abstract
Chemical space exploration motivates the development of data-driven models that bypass explicit computation or experiment. Cost-efficient strategies include the concept of additivity via the many-body expansion that treats a molecule as the sum of its parts. In the context of transition metal chemistry, ligand-wise additivity has been established as a powerful tool to infer the properties of heteroleptic transition metal complexes (TMCs) from homoleptic TMCs to excellent accuracy, including spin-splitting, orbital energies, and reaction energies. Nevertheless, this framework is incompatible with anionic ligands because a stable homoleptic, and thus polyanionic, parent complex cannot be simulated readily. Here, I explore alternative approaches, first identifying the limits of stability of heteroleptic TMCs when successive Cl- anions are added in representative complexes formed with neutral H2O and CO ligands. I establish that expected linear relationships are preserved, albeit not as strongly as in complexes with neutral ligands. I propose data-efficient interpolation and extrapolation schemes for TMCs that achieve root-mean-square errors as low as 0.15-0.36 eV on HOMO/LUMO levels and gaps or ionization potentials and electron affinities and 4 kcal/mol on adiabatic spin-splitting energies for Fe(II) complexes. I show that this approach generalizes well across TMCs with 14 other 3d, 4d, and 5d metals. Finally, I extend this approach to predict properties of thousands of binary and ternary Fe(II) or Zn(II) complexes involving a single neutral ligand and up to two unique anionic ligands by leveraging a handful of calculations. I show how this interpolated space can be used to infer the limits of stable and valid complexes and to discover complexes with novel properties.
MIT Department
Massachusetts Institute of Technology. Department of Chemical Engineering
Massachusetts Institute of Technology. Department of Chemistry
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Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
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DOI of Published Version
10.1021/acs.jcim.5c00636
