Effect of Hydrogen Bonding to Water on the³¹P Chemical Shift Tensor of Phenyl- and Trialkylphosphine Oxides and α-Amino Phosphonates

Abstract

The effect of hydrogen bonding to water on the 31 P NMR chemical shift tensor in the titled compounds has been studied experimentally and simulated theoretically using the DFT-GIAO approach. It has been shown that the effect of hydrogen bonding on the 31 P NMR parameters of trialkylphosphine oxides can be simulated at the GIAO-B3LYP/cc-pVDZ approximation. The influence of molecular conformation on the NMR parameters is small in these compounds. In contrast, the effect of molecular conformation can totally mask the effect of hydrogen bonding in the case of phenylphosphine oxides. The limiting case is a hydrogen bond with water. In these compounds the DFT-GIAO approach can be useful for the analysis of stronger hydrogen bonds only. The GIAO-B3LYP/cc-pVDZ approximation fails to reproduce the 31 P NMR parameters of α-amino phosphonates. Thus, a combination of 31 P NMR and low-cost calculations can be used especially effectively in the study of noncovalent interactions in polycrystalline and noncrystalline materials based on trialkylphosphine oxides. The described research strategy is applicable to the study of the local chemical structures in amorphous materials, at surfaces, and in interfaces.

NMR Study of Solvation Effect on the Geometry of Proton-Bound Homodimers of Increasing Size

“…[9][10][11] At the current stage of knowledge, it is possible to predict the effect of a mutation on the fate of a particular biosystem, to prove this prediction experimentally, and to explain it theoretically. 12 However, for many formally simple systems experimental results have not been reproduced in silico at a reasonable approximation; the strength of dispersive interactions in solution, 13 spectroscopic signatures of protonated water clusters 14,15 and hydrated hydroxyl anion, 16 the structure of water-base complexes in aprotic solutions 17 and amorphous solids [18][19][20] are among such problems. In such cases, the measured spectral parameters have to be assigned to a certain geometry or energy using empirical correlations.…”

Solid State NMR for Nonexperts: An Overview of Simple but General Practical Methods

“…The 31 P isotope is present in 100% natural abundance, has a spin quantum number of 1/2 and a chemical shift range of more than 400 ppm. 31 P NMR can be routinely used in the evaluation of the structure of organic complexes in solution [90,91] and solids [92][93][94] including organometallic compounds [26,[95][96][97][98]. Molecules containing phosphorus are very convenient NMR probes for studying mobility at interfaces [99][100][101].…”

1,3,5-Triaza-7-Phosphaadamantane (PTA) as a 31P NMR Probe for Organometallic Transition Metal Complexes in Solution

“…The 31 P isotope is present in 100% natural abundance, has a spin quantum number of 1/2, as well as a chemical shift range of more than 400 ppm. 31 P NMR can be routinely used in the evaluation of the structure of organic complexes in solution [ 18 , 19 ], interfaces [ 20 , 21 , 22 ], and solids [ 23 , 24 ] including organometallic compounds [ 17 , 25 , 26 ]. Considerable progress has been achieved in recent years in our understanding of the effects of non-covalent interactions on the 31 P chemical shift of P=O groups [ 25 , 27 , 28 ].…”