The First Crystal Structure of an Anti-Geometric Homoleptic Zinc Complex from an Unsymmetric Curcuminoid Ligand

Obregón Mendoza, Marco A.; Escamilla, Gabriela Marmolejo; Tavera-Hernández, Rosario; Sánchez-Obregón, Rubén; Toscano, Rubén A.; Enríquez, Raúl G.

doi:10.3390/cryst14090751

Open AccessArticle

The First Crystal Structure of an Anti-Geometric Homoleptic Zinc Complex from an Unsymmetric Curcuminoid Ligand

by

Marco A. Obregón Mendoza

^†

,

Gabriela Marmolejo Escamilla

^†,

Rosario Tavera-Hernández

,

Rubén Sánchez-Obregón

,

Rubén A. Toscano

and

Raúl G. Enríquez

^*

Instituto de Química, Universidad Nacional Autonomous University of Mexico, Mexico City 04510, Mexico

^*

Author to whom correspondence should be addressed.

^†

These authors contributed equally to this work.

Crystals 2024, 14(9), 751; https://doi.org/10.3390/cryst14090751

Submission received: 10 August 2024 / Revised: 19 August 2024 / Accepted: 22 August 2024 / Published: 24 August 2024

(This article belongs to the Special Issue Structural Studies in Drug Discovery and Development: From the Lead to the Pharmaceutical Form)

Download

Browse Figures

Versions Notes

Abstract

Curcuminoids are widely studied due to their well-recognized therapeutic properties. These molecules are often derivatized with metals, producing their corresponding homoleptic metal complexes. Numerous crystal structures of homoleptic symmetric curcuminoids with physiologically essential metals are known, although the literature lacks reports of homoleptic metal complexes of unsymmetric curcuminoids (or hemi-curcuminoids) as ligands. Three unknowns must be solved when an unsymmetric curcuminoid ligand is reacted with a metal ion: (a) the degree of coordination (MLn); (b) the spatial geometry; and (c) the conformational nature (syn or anti) of the complex. Herein, we report the structure of the anti-isomer of the Zn complex of the hemi-curcuminoid 5-hydroxy-1-(4-methoxyphenyl)hexa-1,4-dien-3-one. While the NMR shows only one set of signals for this homoleptic complex, the unambiguous stereochemistry was established through single-crystal X-ray diffractometry, revealing an anti-hexacoordinated octahedral ML₂ structure.

Keywords: hemi-curcuminoids; curcuminoids; homoleptic zinc metal complex; unsymmetric zinc complex

Graphical Abstract

Share and Cite

MDPI and ACS Style

Obregón Mendoza, M.A.; Escamilla, G.M.; Tavera-Hernández, R.; Sánchez-Obregón, R.; Toscano, R.A.; Enríquez, R.G. The First Crystal Structure of an Anti-Geometric Homoleptic Zinc Complex from an Unsymmetric Curcuminoid Ligand. Crystals 2024, 14, 751. https://doi.org/10.3390/cryst14090751

AMA Style

Obregón Mendoza MA, Escamilla GM, Tavera-Hernández R, Sánchez-Obregón R, Toscano RA, Enríquez RG. The First Crystal Structure of an Anti-Geometric Homoleptic Zinc Complex from an Unsymmetric Curcuminoid Ligand. Crystals. 2024; 14(9):751. https://doi.org/10.3390/cryst14090751

Chicago/Turabian Style

Obregón Mendoza, Marco A., Gabriela Marmolejo Escamilla, Rosario Tavera-Hernández, Rubén Sánchez-Obregón, Rubén A. Toscano, and Raúl G. Enríquez. 2024. "The First Crystal Structure of an Anti-Geometric Homoleptic Zinc Complex from an Unsymmetric Curcuminoid Ligand" Crystals 14, no. 9: 751. https://doi.org/10.3390/cryst14090751

APA Style

Obregón Mendoza, M. A., Escamilla, G. M., Tavera-Hernández, R., Sánchez-Obregón, R., Toscano, R. A., & Enríquez, R. G. (2024). The First Crystal Structure of an Anti-Geometric Homoleptic Zinc Complex from an Unsymmetric Curcuminoid Ligand. Crystals, 14(9), 751. https://doi.org/10.3390/cryst14090751

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Menu

The First Crystal Structure of an Anti-Geometric Homoleptic Zinc Complex from an Unsymmetric Curcuminoid Ligand

Abstract

Share and Cite

Article Metrics

Article Access Statistics

Further Information

Guidelines

MDPI Initiatives

Follow MDPI