Dynamic Phenomena in Self-Complementary {2}-Metallocryptates Probed by Solution 133Cs-NMR. New Insights into Ion Pairing Processes: X-Ray Structure and Solid-State NMR Spectra of a Meandering Species

Maid H, Heinemann FW, Scheurer A, Mooren N, Saalfrank RW, Bauer W (2012)


Publication Status: Published

Publication Type: Journal article

Publication year: 2012

Journal

Publisher: WILEY-V C H VERLAG GMBH

Book Volume: 95

Pages Range: 2429-2445

Journal Issue: 12

DOI: 10.1002/hlca.201200494

Abstract

Two self-complementary {2}-metallocryptates, differing in methyl and phenyl substituents, respectively, have been studied by X-ray analysis, and solid-state and solution NMR. Mixed Mg/Cs metal methyl complex 2 is a linear polymer in the solid state. The two different Cs sites are confirmed by 133Cs-solid-state NMR. By contrast, the analog mixed Mg/Cs metal phenyl complex 4 is a meandering polymer as shown by an actual X-ray analysis. The four non-equivalent Cs-sites in 4 are reflected in the solid-state NMR spectra. Solution 133Cs-NMR spectra of 4 reveal two independent dynamic processes: a fast exchange of Cs within contact ion-pairs and solvent-separated ion-pairs (CIP, SSIP), and a slower exchange of inside endo Cs, surrounded by three ligands, and outside exo Cs involved in the CIP/SSIP equilibrium. Complete line-shape analysis of variable-temperature 133Cs-NMR spectra of 4 yield kinetic parameters of =10.8 kcal/mol for the fast SSIP-CIP exchange and =13.2 kcal/mol for the slower endo/exo exchange of Cs. DOSY-NMR Measurements confirm the monomeric nature of 4 in solution.

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How to cite

APA:

Maid, H., Heinemann, F.W., Scheurer, A., Mooren, N., Saalfrank, R.W., & Bauer, W. (2012). Dynamic Phenomena in Self-Complementary {2}-Metallocryptates Probed by Solution 133Cs-NMR. New Insights into Ion Pairing Processes: X-Ray Structure and Solid-State NMR Spectra of a Meandering Species. Helvetica Chimica Acta, 95(12), 2429-2445. https://doi.org/10.1002/hlca.201200494

MLA:

Maid, Harald, et al. "Dynamic Phenomena in Self-Complementary {2}-Metallocryptates Probed by Solution 133Cs-NMR. New Insights into Ion Pairing Processes: X-Ray Structure and Solid-State NMR Spectra of a Meandering Species." Helvetica Chimica Acta 95.12 (2012): 2429-2445.

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