NMR determination of solvent dependent behavior and XRD structural properties of 4-carboxy phenylboronic acid: A DFT supported study

Highlights: • XRD, NMR and DFT supported structural properties of 4-carboxy phenylboronic. • Solvent effect on the structure. • Anhydrite structure of 4-carboxy phenylboronic. Solvent dependent structural properties of 4-carboxy phenylboronic acid (4-cpba) were investigated by X-ray diffraction (XRD) and nuclear magnetic resonance (NMR) spectroscopic methods. The molecular structure and geometric parameters were determined by some computational methods such as B3LYP/6-31 + G(3df,p), HF/aug-cc-pvtz and MP2/6-31G(d). Detailed elucidation of the structural and spectroscopic properties of 4-cpba was carried out with ¹H, HETCOR and DOSY NMR experiments. Solvent effects on the structural properties were monitored on the changes of ¹H NMR spectra by using various solvents and it was observed that 4-cpba shows serious structural preferences depending on the solvent used.