RESUMO
Hybrid naphthalenediimide/zinc phosphonate materials (NDI/Zn) were prepared by mixing solutions of N,N'-bis(2-phosphonoethyl)-1,4,5,8-naphthalenediimide (PNDI) and zinc nitrate, resulting in the precipitation of the desired compounds. Samples precipitated from water and N,N-dimethylformamide (DMF) were produced. The obtained samples had the expected elemental composition, and the presence of naphthalenediimides (NDI) was ascertained by infrared and UV-visible spectroscopy. All the samples were crystalline, according to powder X-ray diffraction. Nitrogen adsorption isotherms showed the presence of porosity in the NDI/Zn samples. Mesopores with a diameter = 4.1 nm were present in the sample from DMF, with total pore volume reaching 0.13 cm3/g.
RESUMO
The structure of (R)-rasagiline mesylate [(R)-RasH+·Mes-], an active pharmaceutical ingredient used to treat Parkinson's disease, is presented. The structure was determined from laboratory and synchrotron powder diffraction data, refined using the Rietveld method, and validated and optimized using dispersion-corrected DFT calculations. The unit-cell parameters obtained in both experiments are in good agreement and the refinement with both datasets converged to good agreement factors. The final parameters obtained from laboratory data were a = 5.4905â (8), b = 6.536â (2), c = 38.953â (3)â Å, V = 1398.0â (4)â Å3 and from synchrotron powder data were a = 5.487530â (10)â Å, b = 6.528939â (12)â Å, c = 38.94313â (9)â Å, V = 1395.245â (5)â Å3 with Z = 4 and space group P212121. Preferred orientation was properly accounted for using the synchrotron radiation data, leading to a March-Dollase parameter of 1.140â (1) instead of the 0.642â (1) value obtained from laboratory data. In the structure, (R)-RasH+ moieties form layers parallel to the ab plane connected by mesylate ions through N-H...O and C-H...O hydrogen bonds. These layers stack along the c axis and are further connected by C-H...π interactions. Hirshfeld surface analysis and fingerprint plot calculations indicate that the main interactions are: H...H (50.9%), H...C/C...H (27.1%) and H...O/O...H (21.1%).
RESUMO
The structure of racemic (RS)-trichlorme-thia-zide [systematic name: (RS)-6-chloro-3-(di-chloro-meth-yl)-1,1-dioxo-3,4-di-hydro-2H-1λ6,2,4-benzo-thia-di-azine-7-sulfonamide], C8H8Cl3N3O4S2 (RS-TCMZ), a diuretic drug used in the treatment of oedema and hypertension, was determined from laboratory X-ray powder diffraction data using DASH [David et al. (2006 â¸). J. Appl. Cryst. 39, 910-915.], refined by the Rietveld method with TOPAS-Academic [Coelho (2018 â¸). J. Appl. Cryst. 51, 210-218], and optimized using DFT-D calculations. The extended structure consists of head-to-tail dimers connected by π-π inter-actions which, in turn, are connected by C-Clâ¯π inter-actions. They form chains propagating along [101], further connected by N-Hâ¯O hydrogen bonds to produce layers parallel to the ac plane that stack along the b-axis direction, connected by additional N-Hâ¯O hydrogen bonds. The Hirshfeld surface analysis indicates a major contribution of Hâ¯O and Hâ¯Cl inter-actions (32.2 and 21.7%, respectively). Energy framework calculations confirm the major contribution of electrostatic inter-actions (E elec) to the total energy (E tot). A comparison with the structure of S-TCMZ is also presented.