Theory and application of photoelectron spectroscopy. 77. Use of photoelectron spectroscopy in studying rotational isomerism in tetramethyldiphosphine

Schweig, Armin; Thon, N.; Vermeer, Hans J.

doi:10.1021/ja00495a014

Cited by 27 publications

(4 citation statements)

References 4 publications

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“…This assignment gives a lone pair−lone pair splitting in the gauche conformer of about 0.8 eV. This assignment is in line with the one given by Schweig and co-workers for the PE spectra of Me 4 P 2 .…”

Section: Resultssupporting

confidence: 90%

Structure and Photoelectron Spectrum of Tetramethyldiarsane

Sztáray

Szalay

1997

J. Am. Chem. Soc.

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A systematic theoretical investigation of tetramethyldiarsane is presented to help understand its structure and photoelectron spectrum. Full potential energy curve along the C-As-As-C torsion was calculated at the Hartree-Fock (HF) level, and complete geometry optimizations were performed at HF, second-order Many-Body Perturbation Theory (MBPT(2)), and Coupled-Cluster Singles and Doubles (CCSD) levels of theory. Two conformers, anti and gauche, have been found in accordance with the experimental observations. The calculated geometries are in good agreement with the electron diffraction results. Ionization energies were computed by the Equation-of-Motion Coupled-Cluster (EOM-CC) method. The calculations predict a substantial lone-pair splitting for both conformers which contradicts the original assignment of the photoelectron spectrum by Cowley et al. According to the new assignment, the first and third bands belong to the lone pairs of the anti rotamer, the second band is attributed to the n + lone-pair combination in the gauche conformer, while the peak of the n combination is merged with the intense first band previously ascribed exclusively to the anti rotamer. The conformer ratios calculated from the present assignment of the photoelectron spectrum are in good agreement with the quantum-chemical results. Since our assignment contradicts the theoretical reasoning, which the original assignment was based on, a new explanation is presented. We find that the s-character of the lone-pair orbitals increases in the order of nitrogen, phosphorus, arsenic, and antimony which explains not only the increasing pyramidalization of the Me 2 E moiety but also the increasing splitting of the energy of the lone-pair MOs.

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Section: Resultssupporting

confidence: 90%

Structure and Photoelectron Spectrum of Tetramethyldiarsane

Sztáray

Szalay

1997

J. Am. Chem. Soc.

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“…It was our desire to continue this initial work by using the variable temperature method, recently used by two of us (5). It has been previously used with success for studying conformational problems (6)(7)(8)(9)(10).…”

Section: Introductionmentioning

confidence: 99%

Tautomerism of pyrazoline-5-thione and triazoline-5-thione studied by variable temperature photoelectron spectroscopy

Guímon¹,

Pfister‐Guillouzo²,

Begtrup³

1983

Can. J. Chem.

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CLAUDE GUIMON, GENEVIEVE PFISTER-GUILLOUZO, and MIKAEL BEGTRUP. Can. J. Chem. 61, 1197 (1983.Photoelectron spectra at variable temperatures demonstrate that the rate of thermal isomerization of pyrazoline-5-thione ( l a ) into methylthiopyrazolc(s) in the gaseous phase is mctal catalysed. Similar isomerizations of triazolethione (20 and 30) are at best only slightly so.Furthermore, photoelectron spectra and MNDO calculations show that gaseous methylthiopyrazoles (16 and l c ) and mcthylthiotriazolcs (26 and 2c) exist predominantly in planar form for the 6 isomer and in nonplanar form for the c isomer. The AH" for the rotameric equilibria is 2.7-4.2 kJ.mol-'. CLAUDE GUIMON, GENEVIEVE PFISTER-GUILLOUZO et MIKAEL BEGTRUP. Can. J. Chem. 61, 1197Chem. 61, (1983. L'analysc des spectres photoelectroniques enregistrts a I'aide d'une "sonde i ternptrature variable" montre que la transformation en phase vapeur de la pyrazoline-thione-5 ( l a ) en mtthylthio-pyrazole(s) est catalysie par les parois metalliques de la sonde. Cette rtaction d'isomerisation est, semblc-t-il, nettement plus difficile dans le cas des triazolethiones (20 et 30).D'autre part les spectres exptrimentaux et les calculs thtoriques rtalists I'aide de la mtthode MNDO montrent que les composts S-mtthylks ( l b , l c , 26 et 2c) existent prtfkrentiellement sous une forme plane dans le cas des isomkres 6 et une forme non plane dans celui des isornkres c et qu'ils prtsentent un tquilibre entre rotameres (AH" cornpris entre 2.7 et 4.2 kJ. mol-I).

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“…We have employed ultra violet photoelectron spectroscopy (UPS) in the gas phase, a technique which has proven useful in the study of nonbonded interactions, as in dicarbonyls and tricarbonyls (3)(4)(5)(6)(7)(8)(9), in diazodienes [10], diazobicycloalkenes [11,12], azoderivatives [13,14], and thiocyclohexanes [15], and of conformational equi libria in diphosphines [16][17][18], halomethanes [19], and hydrazines [20].…”

Section: Introductionmentioning

confidence: 99%

Study of Sulfur-Sulfur Nonbonded Interactions in Substituted Diphosphine Disulfides by Gas-Phase UV Photoelectron Spectroscopy

Alagna

Cauletti

Andreocci

et al. 1981

Zeitschrift Für Naturforschung A

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Herrn Professor Hermann Hartmann zum 65. Geburtstag gewidmet Ultraviolet photoelectron spectra (UPS) of tetrasubstituted diphosphine disulfides RR'P(S)-P(S)RR' exhibit peculiar 1:2:1 splitting patterns in the region 7.5-9.5 eV for which a throughbond coupling mechanism between the sulfur lone pairs lying in the PPS planes is proposed. Further bond orbitals are related to bands at higher I. E. in the UP spectra.

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Theory and application of photoelectron spectroscopy. 77. Use of photoelectron spectroscopy in studying rotational isomerism in tetramethyldiphosphine

Cited by 27 publications

References 4 publications

Structure and Photoelectron Spectrum of Tetramethyldiarsane

Structure and Photoelectron Spectrum of Tetramethyldiarsane

Tautomerism of pyrazoline-5-thione and triazoline-5-thione studied by variable temperature photoelectron spectroscopy

Study of Sulfur-Sulfur Nonbonded Interactions in Substituted Diphosphine Disulfides by Gas-Phase UV Photoelectron Spectroscopy

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