A combined experimental and theoretical study of benzoxaborole derivatives by Raman and IR spectroscopy, static DFT, and first‐principle molecular dynamics

Abstract

Physicochemical properties of 1,3‐dihydro‐1‐hydroxy‐3‐morpholin‐4‐yl‐2,1‐benzoxaborole (IIa) and 1,3‐dihydro‐1‐ hydroxy‐2,1‐benzoxaborole (IIb) were investigated using a combination of spectroscopic and computational approaches. The compound IIa belongs to the group represented by the prototypical benzoxaborole IIb, which exhibits receptor activity toward sugars in aqueous solution. Additionally, the IIb can serve as a pattern structure for physicochemical description of benzoxaborole derivatives. The infrared and Raman spectroscopy measurements were performed in solvents and in the solid state. Furthermore, experimental findings served as a reference data source for further computational investigations. DFT calculations in vacuo were used to estimate the binding energy of the dimeric forms, indicating the strength of the intermolecular hydrogen bonds. AIM and ELF theories were applied to give an insight into the electronic structure of the studied compounds. The last part of this study contains Car–Parrinello molecular dynamics investigations in the solid state. Computational results indicated that the key intermolecular feature, the pair of hydrogen bonds, is rather harmonic and the extent of the anharmonicity is temperature dependent as shown by the OH stretching envelope calculations performed for IIa. Inclusion of the quantum effects in the proton motion does not significantly change the qualitative description of the intermolecular H‐bond dynamics of the investigated compound. Copyright © 2010 John Wiley & Sons, Ltd.

A combined experimental-computational study of benzoxaborole crystal structures

“…1a), whose 1 H and 13 C NMR spectra in solution and 11 B solid state NMR spectrum have been reported. 14,[16][17][18] Density-functional theory (DFT) calculations were also performed on this molecule, notably to calculate Raman and IR vibration modes and 11 B NMR parameters. 14,18 In contrast, for other molecules like AN2690, extensive characterizations in the solid state using techniques like solid state NMR are still missing, despite the fact that these could be useful for the analysis of its local environment within complex materials or pharmaceutical formulations, especially in cases where X-ray diffraction analyses are impaired.…”

Structure Characterization of [N-Phenylamino(2-boronphenyl)-R-methyl]phosphonic Acid by Vibrational Spectroscopy and Density Functional Theory Calculations

“…To optimize the ground-state geometry of [PhN-(2-PhB(OH) 2 )-R-Me]PO 3 H 2 and to calculate their FT-Raman and FT-IR spectra, the Gaussian 03 suite was used [25]. Our earlier analysis of various types of N-benzylamino(boronphenyl) methylphosphonic acids [26] and a literature study for similar compounds [27,28] noted that the most stable structure of the boronic acid derivatives is a cyclic dimer formed by a pair of intermolecular hydrogen bonds between the boron hydroxyl groups of two monomers. Based on previous experience, here we present the theoretical calculations for the most stable structure of the substituted phenylboronic acid dimer ( Figure 1).…”

“…The triple-split valence basis with a polarization function on heavy atoms and hydrogens (6-311G(d,p)) was applied as the basis set [29]. This type of basis was applied for the calculations of similar phenylboronic acid derivatives and provides reliable results [27,28]. No imaginary wavenumbers were observed during optimization, which demonstrates that the calculated structure correspond Journal of Spectroscopy 3 to energy minima on the potential energy surface for nuclear motion.…”

Lewis acidity and sugar receptor activity of 3-amino-substituted benzoxaboroles and their ortho-aminomethylphenylboronic acid analogues

“…[13][14][15][16][17][18][19][20][21][22] The first 3-amino-substituted benzoxaborole was reported several years ago 23 and some of its physicochemical properties have been recently studied. 24 Experimental studies enabled the synthesis of several 3-amino-substituted benzoxaboroles, 25 which combine structural motifs of benzoxaboroles and ortho-aminomethylphenylboronic acids (Wulff-type receptors) within one molecule. Such a structure was expected to result in exceptional properties, which is the subject of the present work.…”