Abstract
The crystal structures of the solid form of solvated 2,6-bis(1H-imidazol-2-yl)pyridine (H2dimpy) trihydrate, C11H9N5·3H2O·[+solvent], I, and its hydrate hydrochloride salt 2-[6-(1H-imidazol-2-yl)pyridin-2-yl]-1H-imidazol-3-ium chloride trihydrate, C11H10N5+·Cl-·3H2O, II, are reported and analysed in detail, along with potentiometric and spectrophotometric titrations for evaluation of the acid-base equilibria and proton-coupled electron-transfer reactions. Compound I crystallizes in the high-symmetry trigonal space group P3221 with an atypical formation of solvent-accessible voids, as a consequence of the 32 screw axis in the crystallographic c-axis direction, which are probably occupied by uncharacterized disordered solvent molecules. Additionally, the trihydrated chloride salt crystallizes in the conventional monoclinic space group P21/c without the formation of solvent-accessible voids. The acid-base equilibria of H2dimpy were studied by potentiometric and spectrophotometric titrations, and the results suggest the formation of H3dimpy+ (pKa1 = 5.40) and H4dimpy2+ (pKa2 = 3.98), with the electrochemical behaviour of these species showing two consecutive irreversible proton-coupled electron-transfer reactions. Density functional theory (DFT) calculations corroborate the interpretation of the experimental results and support the assignment of the electrochemical behaviour.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
More From: Acta crystallographica. Section C, Structural chemistry
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.