Combined ab initio computational and experimental multinuclear solid‐state magnetic resonance study of phenylphosphonic acid

Abstract

1H, 13C, 17O and 31P NMR parameters, including chemical shift tensors and quadrupolar parameters for 17O, were calculated for phenylphosphonic acid, C6H5PO(OH)2, under periodic boundary conditions. The results are in very good agreement with experimental data and permit the unambiguous assignment of all the sites present in the structure. In particular, the 17O NMR parameters of the P=O and P-OH environments were precisely determined, which should help in the characterization of the bonding mode of phosphonate molecules in hybrid solids. Moreover, the effect of intermolecular interactions on the NMR parameters were investigated by comparing the results of the calculations in the crystal and in an isolated molecule of phenylphosphonic acid.

1H17O nuclear quadrupole double resonance in phenylphosphinic acid and phenylphosphonic acid. 17O quadrupole coupling in P = O and POH bonds

“…[4] The results of the calculation are in good agreement with the experimental data and permit the unambiguous assignment of all the sites present in the structure.…”

Citrate bridges between mineral platelets in bone

“…Multinuclear solid-state NMR spectroscopy was used to glean information about the environment of the phosphatic and citrate anions in the structure, which we then used to build a series of possible structural models. These models were geometry-optimized using first principles electronic structure calculations through the Cambridge Serial Total Energy Package (CASTEP) software (28)(29)(30) and the calculated NMR parameters and powder XRD patterns for the resulting optimized structures compared with experimental data to determine the plausibility of each structure (i.e., the degree to which the NMR parameters and powder XRD pattern calculated for a model structure agree with the experimental data). The true structure, because of its inherent disorder, is best described as the coexistence of a set of structures in this approach, and our ultimate goal here is to find a set of structures that defines the range of structural disorder within OCP-citrate.…”

Chemical shift computations on a crystallographic basis: some reflections and comments

“…only one geometry) are minimised, resulting in an expectation of increased accuracy from that point of view and throwing the burden of accuracy on the validity of the computations. Some CASTEP-NMR results for anisotropies have been reported for˛testosterone, 21 phenylphosphonic acid 30 and for several aminoacids. 31 In Table 5, we report the computed shielding parameters for the antibiotic ampicillin (VIII) and compare them with the experimental results of Antzutkin et al 42 The details of the computation are identical to those reported in Ref.…”

“…Indeed assignments become significantly more robust when different types of parameters are used together. For example, Yates et al 32 and Gervais et al 30,31 showed that 17 O quadrupole coupling constants could be used in conjunction with 17 O chemical shifts to make unambiguous assignments in cases where overlap of the isotropic shifts made assignment on the basis of shift values alone impossible. The value of NMR-CASTEP in providing results for all nuclides in a system is emphasised by heteronuclear multidimensional experiments.…”