Dynamic nuclear magnetic resonance study of fluorine exchange in liquid sulfur tetrafluoride

Klemperer, W. G.; Krieger, Jeanne K.; McCreary, Michael D.; Muetterties, E. L.; Traficante, Daniel D.; Whitesides, George M.

doi:10.1021/ja00857a012

Cited by 37 publications

(11 citation statements)

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“…Of the two suggested permutation mechanisms, the turnstyle mechanism 23,28 and the Berry pseudo rotation, 23 the latter has been demonstrated by NMR spectroscopy to occur in SF 4 . [24][25][26] We explored the Berry pseudo rotation of tellurium tetrafluoride and tellurium tetrachloride by theoretical methods. The crosssection of the potential energy surface as plotted along the valence angle X-Te-X coordinate are shown in Fig.…”

Section: Pseudorotationmentioning

confidence: 99%

“…29 Thus we can conclude that the topomerization in TeF 4 and TeCl 4 occurs via the Berry pseudorotation (as already demonstrated for sulfur tetrafluoride). [24][25][26] The normal mode due to which the TeX 4 molecules follow this transformation, i.e. C 2v → C 4v → C 2v , corresponds to that of the lowest frequency, 121 cm -1 and 76 cm -1 (B3LYP) in the fluoride and chloride, respectively.…”

Section: Pseudorotationmentioning

confidence: 99%

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The structures of tellurium(iv) halides in the gas phase and as solvated molecules

et al. 2010

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The structures of molecular tellurium tetrafluoride and tellurium tetrachloride were determined by a combination of gas-phase electron diffraction, mass spectrometry and quantum chemical calculations. The combined GED/MS experiments showed no evidence of decomposition of TeF(4) and TeCl(4). No ions of oligomeric (dimeric, trimeric, etc.) or any other composition were found in the mass spectra. The monomeric molecules possess a pseudo trigonal bipyramidal structure (C(2v) symmetry) with the equatorial Te-X distances being shorter than the axial ones. The fluorine atoms are bent away from the lone pair resulting in X(eq)-Te-X(eq) and X(eq)-Te-X(ax) bond angles smaller than 120 and 90 degrees, respectively. The structure of solvates TeF(4) (THF)(2), TeF(4) (dioxane) TeF(4) (DME)(2), TeF(4)(Et(2)O) TeF(4)(toluene), TeCl(4)(CH(3)CN)(2), TeCl(4)(DME)(2) and TeCl(4)(dioxane) were determined by X-ray diffraction. The structures of tellurium tetrafluoride solvates are strongly influenced by the choice of the solvent molecules. Monomeric TeF(4) units were obtained with THF, DME and dioxane whereas fluoride bridged coordination polymers were formed using diethyl ether or toluene. All tellurium tetrachloride solvates studied contain monomeric TeCl(4) units with coordinated solvent molecules. Coordination numbers range from four in the gas phase to eight in the TeF(4) dimethoxyethane solvate. Geometric parameters of the TeX(4) molecules in the crystal, solvates and gas phase were compared. DFT, MP2, CCSD, CCSD(T) methods were applied for calculation of geometric and vibrational characteristics of free TeX(4) molecules (X = F, Cl). The pseudorotation barriers were estimated and an NBO analysis was performed. It was shown that both, GED and theoretical, quantitative results are in agreement with the qualitative results of the VSEPR model.

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Section: Pseudorotationmentioning

confidence: 99%

Section: Pseudorotationmentioning

confidence: 99%

The structures of tellurium(iv) halides in the gas phase and as solvated molecules

et al. 2010

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“…NMR data indicate that the ten-electron complex SF4 undergoes axial-equatorial ligand exchange through a Berry pseudorotation mechanism. 69 Barriers must be on the order of a few kcal/mol, comparable in size to those of the tenelectron AB5 series. Although ten-electron AB4 and AB5 systems are floppy, the eight-electron AB3 systems are much more rigid.…”

mentioning

confidence: 99%

The shapes and other properties of non-transition element complexes. 3. AB5

Gimarc¹

1978

J. Am. Chem. Soc.

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“…Sulfur tetrafluoride (SF 4 ), first reported in 1911, has a seesaw ( C 2 v ) geometry. On the basis of 19 F NMR data recorded at different temperatures, SF 4 is considered fluxional as it undergoes fast exchange of ligand positions at room temperature. − Klemperer and co-workers concluded in 1975 that the nonrigidity of SF 4 arises from Berry pseudorotation, , where the axial F–S–F angle closes accompanied by the opening of the equatorial F–S–F angle, passing through a TS with C 4 v symmetry.…”

Section: Resultsmentioning

confidence: 99%

Describing Polytopal Rearrangements of Fluxional Molecules with Curvilinear Coordinates Derived from Normal Vibrational Modes: A Conceptual Extension of Cremer–Pople Puckering Coordinates

Zou

Tao

Kraka

2020

J. Chem. Theory Comput.

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In this work a new curvilinear coordinate system is presented for the comprehensive description of polytopal rearrangements of N-coordinate compounds (N = 4–7) and systems containing an N-coordinate subunit. It is based on normal vibrational modes and a natural extension of the Cremer–Pople puckering coordinates (J. Am. Chem. Soc.1975971354) together with the Zou–Izotov–Cremer deformation coordinates (J. Phys. Chem. A20111158731) for ring structures to N-coordinate systems. We demonstrate that the new curvilinear coordinates are ideal reaction coordinates describing fluxional rearrangement pathways by revisiting the Berry pseudorotation and the lever mechanism in sulfur tetrafluoride, the Berry pseudorotation and two Muetterties’ mechanisms in pentavalent compounds, the chimeric pseudorotation in iodine pentafluoride, Bailar and Ray-Dutt twists in hexacoordinate tris-chelates as well as the Bartell mechanism in iodine heptafluoride. The results of our study reveal that this dedicated curvilinear coordinate system can be applied to most coordination compounds opening new ways for the systematic modeling of fluxional processes.

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Dynamic nuclear magnetic resonance study of fluorine exchange in liquid sulfur tetrafluoride

Cited by 37 publications

References 0 publications

The structures of tellurium(iv) halides in the gas phase and as solvated molecules

The structures of tellurium(iv) halides in the gas phase and as solvated molecules

The shapes and other properties of non-transition element complexes. 3. AB5

Describing Polytopal Rearrangements of Fluxional Molecules with Curvilinear Coordinates Derived from Normal Vibrational Modes: A Conceptual Extension of Cremer–Pople Puckering Coordinates

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