X-ray diffraction and phosphorus-31 NMR studies of the dynamically disordered 3:2 phenol–triphenylphosphine oxide complex

An 17O NMR and Quantum Chemical Study of Monoclinic and Orthorhombic Polymorphs of Triphenylphosphine Oxide

“…The information available from previous NMR studies on phosphine oxides, their complexes, and their derivatives has generally been restricted to the determination of isotropic 31 P and 17 O chemical shifts (CS), δ iso , and isotropic J coupling constants from solution NMR spectroscopy, − as well as δ iso ( 31 P) from 31 P magic-angle spinning (MAS) NMR spectroscopy in the solid state. − Some information on the 31 P ( I = 1/2) CS tensor is also available. − In contrast, results from 17 O ( I = 5/2) NMR spectroscopy of phosphine oxides in the solid state are lacking. The range of oxygen isotropic chemical shifts in solution is on the order of 2500 ppm with phosphine oxides generally falling in the range of 20−100 ppm. − Overviews of 17 O nuclear quadrupolar coupling constants ( C Q ), which are very sensitive to the electric field gradient (EFG) about the 17 O nucleus, are available. − Values of C Q ( 17 O) range from less than 1.0 MHz (e.g., MoO 4 2- ) to greater than 15 MHz (e.g., H 2 O 2 ).…”

“…The information available from previous NMR studies on phosphine oxides, their complexes, and their derivatives has generally been restricted to the determination of isotropic 31 P and 17 O chemical shifts (CS), δ iso , and isotropic J coupling constants from solution NMR spectroscopy, [1][2][3][4][5][6][7][8][9][10][11] as well as δ iso ( 31 P) from 31 P magic-angle spinning (MAS) NMR spec-troscopy in the solid state. [12][13][14][15] Some information on the 31 P (I ) 1/2) CS tensor is also available.…”

“…[12][13][14][15] Some information on the 31 P (I ) 1/2) CS tensor is also available. [16][17][18][19][20][21][22][23][24][25] In contrast, results from 17 chemical shifts in solution is on the order of 2500 ppm with phosphine oxides generally falling in the range of 20-100 ppm. [26][27][28] Overviews of 17 O nuclear quadrupolar coupling constants (C Q ), which are very sensitive to the electric field gradient (EFG) about the 17 O nucleus, are available.…”

“…[16][17][18][19][20][21][22][23][24][25] In contrast, results from 17 chemical shifts in solution is on the order of 2500 ppm with phosphine oxides generally falling in the range of 20-100 ppm. [26][27][28] Overviews of 17 O nuclear quadrupolar coupling constants (C Q ), which are very sensitive to the electric field gradient (EFG) about the 17 O nucleus, are available. [29][30][31] Values of C Q ( 17 O) range from less than 1.0 MHz (e.g., MoO 4 2-) to greater than 15 MHz (e.g., H 2 O 2 ).…”

“…The focus of this work is to characterize the anisotropic oxygen NMR interaction tensors for the prototypal terminal oxygen in the PO bonding environment in the solid state. The 17 O NMR spectra of the 31 P- 17 O spin pair in solid triphenylphosphine oxide, Ph 3 PO, should in principle provide a rare opportunity where one must consider all four fundamental NMR interactions simultaneously when carrying out spectral simulations. For the 31 P- 17 O spin pair, these interactions are the following: (i) the 17 O quadrupolar interaction; (ii) the 17 O chemical shift interaction; (iii) the direct dipolar coupling interaction between 17 O and 31 P; (iv) the indirect nuclear spin-spin (J) coupling interaction between 17 O and 31 P. Given the number of parameters which will be indicative of the bonding environment at oxygen, 17 O solid-state NMR spectroscopy should provide an important perspective on the nature of the phosphorus-oxygen bond, a topic of ongoing debate.…”