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Updated: Jan 14, 2026

Line Shape Analysis of Dynamic NMR Spectra for Characterizing Coordination Sphere Rearrangements at a Chiral Rhenium Polyhydride Complex
Published on: July 27, 2022
Rhenium Chalcogenide Clusters Containing para-Substituted Phenylacetylide Ligands: Synthesis, Characterization, and
Katherine L Helmink1, Cory A Hicks1, B Sage Lauper-Cook1
1Department of Chemistry, Illinois State University, Normal, Illinois 61790-4160, United States.
Abstract:
Four new organometallic [Re6Se8]2+-based cluster complexes containing para-substituted phenylacetylide ligands, [Re6Se8(PEt3)5(CC-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(CC-C6H4-NO2)]+, [Re6Se8(PEt3)5(CC-C6H4-CO2Me)]+, and [Re6Se8(PEt3)5(CC-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(CC-C6H5)]-(SbF6), reveal a correlation between the Hammett parameter σp 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(CC-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.
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