The Phosphorus Ylide CH<sub>2</sub>PH<sub>3</sub> is Stable in the Gas Phase

Keck, Helmut; Kuchen, Wilhelm; Tommes, Peter; Terlouw, Johan K.; Wong, Thomas

doi:10.1002/anie.199200861

Cited by 24 publications

(6 citation statements)

References 27 publications

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“…In case of the PH 3 adducts, only A-and F-type structures were obtained, the A-type structure being always the more stable one. This is in accordance with the general understanding 137 that in the condensed phase H-ylides of phosphorus (F) rearrange to their phosphane (A) counterparts via 1,2-H-shift 138 with the exception of some notable kinetically hindered cases. 139,140 In case of 1, 2, 7, and 8, no F-type structure could be optimized (neither at ω-B97XD/cc-pVTZ nor at M06-2X/cc-pVTZ see Tables 1 and S4), only very weakly bonded complexes with P−C distance over 3.2 Å could be obtained.…”

Section: ■ Results and Discussionsupporting

confidence: 91%

Stretching the P–C Bond. Variations on Carbenes and Phosphanes

2020

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The stability and the structure of adducts formed between four substituted phosphanes (PX3, X:H, F, Cl, and NMe2) and 11 different carbenes have been investigated by DFT calculations. In most cases, the structure of the adducts depends strongly on the stability of the carbene itself, exhibiting a linear correlation with the increasing dissociation energy of the adduct. Carbenes of low stability form phosphorus ylides (F), which can be described as phosphane → carbene adducts supported with some back-bonding. The most stable carbenes, which have high energy lone pair, do not form stable F-type structures but carbene → phosphane adducts (E-type structure), utilizing the low-lying lowest unoccupied molecular orbital (LUMO) of the phosphane (with electronegative substituents), benefiting also from the carbene–pnictogen interaction. Especially noteworthy is the case of PCl3, which has an extremely low energy LUMO in its T-shaped form. Although this PCl3 structure is a transition state of rather high energy, the large stabilization energy of the complex makes this carbene–phosphane adduct stable. Most interestingly, in case of carbenes with medium stability both F- and E-type structures could be optimized, giving rise to bond-stretch isomerism. Likewise, for phosphorus ylides (F), the stability of the adducts G formed from carbenes with hypovalent phosphorus (PXphosphinidene) is in a linear relationship with the stabilization of the carbene. Adducts of carbenes with hypervalent phosphorus (PX5) are the most stable when X is electronegative, and the carbene is highly nucleophilic.

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Section: ■ Results and Discussionsupporting

confidence: 91%

Stretching the P–C Bond. Variations on Carbenes and Phosphanes

2020

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“…Some of these theoretical predictions would be experimentally confirmed, and, for instance, CH 2 PH 3 would be experimentally detected and characterized in 1992 (Keck et al, 1992). However, to the best of our knowledge, the sulfonium ylide has not been experimentally detected so far and the halonium ylides were the subjects of some controversy.…”

Section: Theoretical Characterization Of Elusive or Non‐conventionmentioning

confidence: 95%

Computational chemistry: A useful (sometimes mandatory) tool in mass spectrometry studies

Alcamı́¹,

Mó²,

Yáñez³

2001

Mass Spectrometry Reviews

170

144

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In this review, we present a brief summary of the theoretical methods most frequently used in gas-phase ion chemistry. In subsequent sections, the performance of these methods is analyzed, paying attention to the reliability of geometries, vibrational frequencies, energies, and entropies. The possible pathologies of the different methods, in the form of instabilities of the wave function or spin contamination problems, are discussed. Several examples are presented to illustrate the usefulness of ab initio or density functional theory (DFT) methods to predict the existence of elusive molecules and/or to characterize non-conventional structures, and to rationalize the charge redistributions normally associated with ion-molecule interactions and which result in bond-weakening or bond-reinforcement effects. Finally, the role of non-classical structures in ion-molecule interactions is also illustrated with different examples.

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“…Der vormalige Koordinationsraum des Lithiumatoms wird durch die P-st‰ndigen Wasserstoffatome besetzt, von denen jedes eine schwache Wasserstoffbr¸cke zu je einem Stickstoffatom ausbildet (PH¥¥¥N 283(4), 298(4) pm; P-H-N 88(2)±94(2)8). [2] Darunter befinden sich der hexaedrische K‰fig (Zusammensetzung M 18 L 6 , M ¼ Metall, L ¼ Ligand), [3] w¸rfelartige K‰fige (M 12 L 8 und M 6 L 8 ) [4] sowie aus 50 Komponenten bestehende hoch symmetrische Dodekaeder. [12] Die trigonal-planare Koordination der Kohlenstoffatome (Bindungswinkelsumme 3608) und die P-C-Abst‰nde (168.2(5)±169.7(5) pm) in den Ylidgruppen ‰hneln denen anderer C(SiMe 3 ) 2 -substituierter Phosphoniumylide (P-C 168(3) pm).…”

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