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

Abstract

<jats:p>A complete analysis of the <jats:sup>31</jats:sup>P, <jats:sup>13</jats:sup>C and <jats:sup>1</jats:sup>H 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 <jats:sup>1</jats:sup>J(PP) and <jats:sup>1</jats:sup>J(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(<jats:sup>31</jats:sup>P) values. </jats:p><jats:p>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.</jats:p>

The Triphosphide (tBu3Si)2P3Na: Formation, X-ray and Ab initio Structure Analyses, Protonation and Oxidation to Triphosphane (tBu3Si)2P3H and Hexaphosphanes (tBu3Si)4P6⋆

“…The 31 P-NMR data of 12 parallel, to a large degree, those of tBu 2 P 3 ϪP 3 tBu 2 [16] . The chemical shifts of the phosphorus nuclei appear at high field [δ(P-1) ϭ Ϫ142.6, δ(P-2) ϭ Ϫ194.8, δ(P-3) ϭ Ϫ210.8], as is generally found for δ 31 P in cyclotriphosphanes [23] [24] . The direct connection of the two P 3 rings is indicated by the large and negative coupling constant between P-1 and P-1Ј.…”

“…The larger coupling constant between P-2 and P-3 indicates a cis orientation of the substituents H and SitBu 3 at these phosphorus atoms [22] . For 11 the 31 P-NMR chemical shifts, as well as the PϪP coupling constants, fall in the range characteristic for cyclotriphosphanes [23] [24] . Figure 3.…”

Analysis of substituent effects on31P NMR chemical shifts: PX2Y molecules

“…These are associated with the distinctly widened "cisÏ tBuÈPÈP angle of 123¡ (known from the crystal structure). 23 …”

Pentacarbonyl(triisopropylcyclotriphosphan)wolfram(0), [W(CO)5(C9H21P3)]

“…In den vergangenen Jahren konnten Verbindungen mit Gerfisten aus Phosphor-Ketten oder-Ringen in bis dahin unerwarteter Vielfalt dargesteUt und umfassend charakterisiert werden [Ubersicht in Baudler (1982)]. Dieses gilt im besonderen for die PhosphorDreiringverbindungen, wobei ausser solchen mit verschiedenen Heteroatom-Typen im Ring auch bemerkenswert bestS.ndige homocyclische Vertreter (RP) 3 in reiner Form erhalten wurden.…”

“…Dieses gilt im besonderen for die PhosphorDreiringverbindungen, wobei ausser solchen mit verschiedenen Heteroatom-Typen im Ring auch bemerkenswert bestS.ndige homocyclische Vertreter (RP) 3 in reiner Form erhalten wurden. Inzwischen liegt vom Tri-tert-butylcyclotriphosphan, (t-BuP)3, eine Kristallstrukturanalyse vor (Hahn, Baudler, Krfiger & Tsay, 1982 (Tebbe & Feh6r, 1984 (Hahn et al, 1982) und [(t-BuP)3Cr(CO) s] (Tebbe & Feb+r, 1984) beruhen.…”