Theoretical study of the reactions of pentacoordinated trigonal bipyramidal phosphorus compounds: PH5, PF5, PF4H, PF3H2, PF4CH3, PF3(CH3)2, P(O2C2H4)H3, P(OC3H6)H3, and PO5H4-

Phosphorus heterocycles from 2‐(2‐hydroxyphenyl)‐1H‐benzimidazole

“…Chemical shift and coupling constants 3 J ( 31 P, 1 H) are characteristic of its equatorial position [35]. On the other hand, the shift of the P-phenyl protons in 24 with respect to its P(III) precursor 7 reveals P-phenyl equatorial position [20], which is in accord with data of diphenylbicyclophosphorane of Scheme 10 [32].…”

“…A phosphorus tbp geometry is assumed with catechol and ligand 1 bonded in the most stable apicalequatorial way [18,19]. On the other hand, it is expected that nitrogen atoms must occupy the equatorial positions that favor electronic donation to phosphorus [20]. Although enantiomers for 9a and 9b exist, we will not depict them [21].…”

Berry Pseudorotation Mechanism for the Interpretation of the 19F NMR Spectrum in PF5 by Ab Initio Molecular Dynamics Simulations

“…Finally, electronic and Gibbs free-energy barriers associated to the Berry pseudorotation are equal to % 4 kcal mol À1 . As for the structural properties, the activation energy is found to be close to other theoretical approaches (2.76-5.07 kcal mol À1 ) [13,14,16,17,53,55] or experimental estimation (3.04-3.91 kcal mol…”

“…The Berry pseudorotation [11,12] mechanism (Scheme 1) is commonly invoked to explain the 19 F NMR spectrum of PF 5 and much attention has been devoted to the determination of the exchange mechanism, energy barrier and exchange rate. [13][14][15][16][17] Recent developments in various computational methods for the study of nuclear magnetic resonance spectra provide new possibilities for the analysis and interpretation of experimental spectra. State-of-the-art ab initio methods nowadays allow the accurate treatment of chemical shielding and indirect spinspin coupling constants.…”

NMR study of spirophosphoranes derived from 2-aminophenols

“…Due to the strong Lewis acidity of the phosphorus(V) atom [2][3][4], the more efficient electron-donor atoms occupy equatorial sites; in this position the surroundings of the nitrogen atom become trigonal planar due to a retrocoordinative p bond from the nitrogen to the phosphorus atom [5]. The p bonding that occurs only for equatorial donor atoms is due to the electrodeficient character of the phosphorus(V).…”