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Updated: May 9, 2026

Line Shape Analysis of Dynamic NMR Spectra for Characterizing Coordination Sphere Rearrangements at a Chiral Rhenium Polyhydride Complex
Published on: July 27, 2022
Probing isotope shifts in 103Rh and 195Pt NMR spectra with density functional theory
John C Davis1, Michael Bühl, Klaus R Koch
1School of Chemistry, University of St. Andrews, North Haugh, St. Andrews, Fife KY16 9ST, United Kingdom.
Abstract:
Zero-point vibrationally averaged (rg(0)) structures were computed at the PBE0/SDD/6-31G* level for the [Pt(35)Cln(37)Cl5-n(H2(18)O)](-) (n = 0-5), cis-Pt(35)Cln(37)Cl4-n(H2(18)O)(H2(16)O) (n = 0-4), fac-[Pt(35)Cln(37)Cl3-n(H2(18)O)(H2(16)O)2](+) (n = 0-3), [Pt(35)Cln(37)Cl5-n((16/18)OH)](2-) (n = 0-5), cis-[Pt(35)Cln(37)Cl4-n((16/18)OH)2](2-) (n = 0-4), fac-[Pt(35)Cln(37)Cl3-n((16/18)OH)3](2-) (n = 0-3), cis-[Pt(35)Cln(37)Cl2-n((16/18)OH)4](2-) (n = 0-2), [Pt(35)Cln(37)Cl1-n((16/18)OH)5](2-) (n = 0-1), [Rh(35)Cln(37)Cl5-n(H2O)](2-) (n = 0-5), cis-[Rh(35)Cln(37)Cl4-n(H2O)2](-) (n = 0-4), and fac-Rh(35)Cln(37)Cl3-n(H2O)3 (n = 0-3) isotopologues and isotopomers. Magnetic shielding constants, computed at the ZORA-SO/PW91/QZ4P/TZ2P level, were used to evaluate the corresponding (35/37)Cl isotope shifts on the (195)Pt and (103)Rh NMR spectra, which are known experimentally. While the observed effects are reproduced reasonably well computationally in terms of qualitative trends and the overall order of magnitude (ca. 1 ppm), quantitative agreement with experiment is not yet achieved. Only small changes in M-Cl and M-O bonds upon isotopic substitution, on the order of femtometers, are necessary to produce the observed isotope shifts.
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