| Texto completo | |
| Autor(es): |
Guerra, Renan B.
;
Huamani, Luis S. C.
;
Tenorio, Juan C.
;
Guimaraes, Willian M.
;
Bonacin, Juliano A.
;
Barboza Formiga, Andre Luiz
Número total de Autores: 6
|
| Tipo de documento: | Artigo Científico |
| Fonte: | ACTA CRYSTALLOGRAPHICA SECTION C-STRUCTURAL CHEMISTRY; v. 75, p. 20-pg., 2019-10-01. |
| Resumo | |
The crystal structures of the solid form of solvated 2,6-bis(1H-imidazol-2-yl)pyridine (H(2)dimpy) trihydrate, C11H9N5 center dot 3H(2)O center dot[+solvent], I, and its hydrate hydrochloride salt 2-[6-(1H-imidazol-2-yl)pyridin-2-yl]-1H-imidazol-3-ium chloride trihydrate, C11H10N5+center dot Cl-center dot 3H(2)O, 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 P3(2)21 with an atypical formation of solvent-accessible voids, as a consequence of the 3(2) 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 P2(1)/c without the formation of solvent-accessible voids. The acid-base equilibria of H(2)dimpy were studied by potentiometric and spectrophotometric titrations, and the results suggest the formation of H(3)dimpy(+) (pK(a1) = 5.40) and H(4)dimpy(2+) (pK(a2) = 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. (AU) | |
| Processo FAPESP: | 14/50906-9 - INCT 2014: em Materiais Complexos Funcionais (INOMAT) |
| Beneficiário: | Fernando Galembeck |
| Modalidade de apoio: | Auxílio à Pesquisa - Temático |
| Processo FAPESP: | 17/23960-0 - Estudo de mecanismo de oxidação de água por catalisadores operando em pH=7 e sua incorporação em eletrodos impressos em 3D |
| Beneficiário: | Juliano Alves Bonacin |
| Modalidade de apoio: | Auxílio à Pesquisa - Regular |
| Processo FAPESP: | 13/22127-2 - Desenvolvimento de novos materiais estratégicos para dispositivos analíticos integrados |
| Beneficiário: | Lauro Tatsuo Kubota |
| Modalidade de apoio: | Auxílio à Pesquisa - Temático |