An investigation of the ring size of cyclopolyphosphines

Smith, Lawrence R.; Mills, Jerry L.

doi:10.1021/ja00429a020

Cited by 60 publications

(26 citation statements)

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“…In their review, Maier et al 21 concluded that for phosphanes "the electronegativity of substituents on phosphorus and the angles between them are the two most important variables determining 31P chemical shifts.Ï A bond angleÈchemical shift relationship has been found in cyclooligophosphanes, cyclo-(PR) where n , d(31P) depends on the average endocyclic PÈPÈP angle. 22 The cyclotriphosphanes (experimental23 d(31P) …”

Section: Nmr Shift Correlationsmentioning

confidence: 99%

Analysis of substituent effects on31P NMR chemical shifts: PX2Y molecules

Dransfeld¹,

Schleyer²

1998

Magn. Reson. Chem.

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Section: Nmr Shift Correlationsmentioning

confidence: 99%

Analysis of substituent effects on31P NMR chemical shifts: PX2Y molecules

Dransfeld¹,

Schleyer²

1998

Magn. Reson. Chem.

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“…V) die Abhängigkeit der chemischen Verschiebung vom exocyclischen P-P-C-Bindungswinkel zu 3,0 ppm/grad berechnet werden. Dieser Wert steht R R R in guter Übereinstimmung mit der Tieffeldverschiebung von ~3,5 ppm/grad, die sich bei Änderung der Ringgröße mit zunehmendem enrfocyclischen Bindungswinkel ergibt [9]. Gleichzeitig wird jedoch deutlich, daß die Ringgröße als alleiniges Kriterium für den <3( 3l P)-Erwartungswert von Cyclophosphanen [9] nicht ausreicht, sondern zusätzlich die Sperrigkeit der Substituenten, die den exocyclischen Bindungswinkel beeinflussen, zu berücksichtigen ist.…”

Section: A) Chemische Verschiebungenunclassified

Beiträge zur Chemie des Phosphors, 116 Kernresonanzspektren und Kristallstruktur von Tri-tert-butylcyclotriphosphan / Contributions to the Chemistry of Phosphorus, 116 NMR Spectra and Crystal Structure of Tri-tert-butylcyclotriphosphane

Hahn

Baudler

Krüger

et al. 1982

Zeitschrift Für Naturforschung B

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A complete analysis of the 31P, 13C and 1H NMR spectra of tri-tert-butyl-cyclotriphosphane (1) was carried out and the resulting NMR parameters were correlated with the X-ray data of the molecule. It was found, that increasing P-P-C-bond angles correspond to a downfield shift and an increase of the absolute values of the negative 1J(PP) and 1J(PC) coupling constants. Generally, the chemical shifts of cyclotriphosphanes as well as of larger cyclic phosphanes depend on the endo- and exocyclic bond angles, the dihedral angle between the electron lone pairs of adjacent P-atoms, and the β-effect. On the basis of the X-ray and chemical shift data of 1, the bond angles of other cyclotriphosphanes can be deduced from their δ(31P) values. 1 crystallizes triclinically in the space group P1̄ with Z = 4 formula units. The X-ray analysis confirms the NMR-spectroscopically determined three-membered ring structure with the tert-butyl substituents on either side of the ring plane. Due to steric hindrance between the two tert-butyl groups in cis position, the corresponding P-P-C-bond angles show the largest values so far observed for organylcyclophosphanes.

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“…Surprisingly, contrary to [42], when diethyl ether instead of THF had been used as a solvent, no product 8 was obtained. The parent peak (m/z 540) in mass spectrum of 8 clearly indicates the five-membered ring [42,45,47]. The reaction of (PhP) 5 with metallic selenium affords compound 9 (89% yield) [48][49][50].…”

Section: Resultsmentioning

confidence: 99%