Rhenium Chalcogenide Clusters Containing para-Substituted Phenylacetylide Ligands: Synthesis, Characterization, and Investigation of Substituent Effects on Spectroscopic and Electrochemical Properties

Authors

Katherine L. Helmink, Illinois State University
Cory A. Hicks, Illinois State University
B. Sage Lauper-Cook, Illinois State University
Steven J. Peters, Illinois State University
Christopher J. A. Daley, University of San Diego
Yann Molard, Universite de Rennes
Lisa F. Szczepura, Illinois State UniversityFollow

Document Type

Article

Publication Date

2025

Publication Title

Organometallics

Abstract

Four new organometallic [Re₆Se₈]²⁺-based cluster complexes containing para-substituted phenylacetylide ligands, [Re₆Se₈(PEt₃)₅(C≡C–C₆H₄–X)](SbF₆) where X = NO₂, CO₂Me, CH₃, and OMe, have been synthesized and fully characterized using ¹H, ¹³C{¹H} and ³¹P{¹H} NMR, IR, and UV–vis spectroscopy, HRMS, and elemental analysis. Three of these cluster complexes, [Re₆Se₈(PEt₃)₅(C≡C–C₆H₄–NO₂)]⁺, [Re₆Se₈(PEt₃)₅(C≡C–C₆H₄–CO₂Me)]⁺, and [Re₆Se₈(PEt₃)₅(C≡C–C₆H₄–CH₃)]⁺ were also characterized via single-crystal X-ray diffraction. Electrochemical studies of these newly reported complexes, as well as the unsubstituted phenylacetylide complex, [Re₆Se₈(PEt₃)₅(C≡C–C₆H₅)](SbF₆), reveal a correlation between the Hammett parameter σ_p and the [Re₆Se₈]^3+/2+ couple. The reversibility of this oxidative process is also significantly impacted by the nature of the para-substituent. The photophysical properties of these phenylacetylide cluster complexes (including cis- and trans-[Re₆Se₈(PEt₃)₄(C≡C–C₆H₅)₂]) in solution and in the powder-phase are reported. Our findings confirm para-substituent effects on emission; however, the trend is opposite to that found in previous studies involving [Re₆Se₈]²⁺ clusters containing para-substituted benzonitrile ligands.

Funding Source

This material is based upon work supported by the National Science Foundation under NSF RUI-2400260. Acknowledgement is also made to the donors of the American Chemical Society Petroleum Research Fund (67572-UR3) for support of this research. This article was published Open Access thanks to a transformative agreement between Milner Library and ACS.

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

DOI

10.1021/acs.organomet.5c00245

Comments

First published in Organometallics (2025): https://doi.org/10.1021/acs.organomet.5c00245

Recommended Citation

Helmink, K. L.; Hicks, C. A.; Lauper-Cook, B. S.; Peters, S. J.; Daley, C. J. A.; Molard, Y.; Szczepura, L. F. Rhenium Chalcogenide Clusters Containing Para-Substituted Phenylacetylide Ligands: Synthesis, Characterization, and Investigation of Substituent Effects on Spectroscopic and Electrochemical Properties. Organometallics 2025, 44 (19), 2209–2218. https://doi.org/10.1021/acs.organomet.5c00245.