Publications by authors named "I Svoboda"
Article Synopsis
- A mononuclear NiL complex was synthesized using bis-N,N'-salicylidene-1,3-propanediamine and nickel(II) salts, then reacted with ZnBr2 and co-ligands like pyrazole and 3,5-lutidine to create diheteronuclear complexes.
- The characterization of the complexes involved techniques such as elemental analysis, thermogravimetry (TG), infrared (IR) spectroscopy, and mass spectrometry.
- Theoretical analyses using Gaussian09 assessed formation enthalpies, dipole moments, and electronic structure, revealing that lutidine, as a stronger coligand, induces a square pyramidal structure in the NiL complex.
Three new nitrogen-rich energetic compounds, N-(5-chloro-2,4-dinitrophenyl)hydrazine (1), N-(5-chloro-2,4-dinitrophenyl)guanidine (2) and N-(5-chloro-2,4-dinitrophenyl)-4-aminopyrazole (3) prepared by the nucleophilic substitution reaction of 1,3-dichloro-4,6-dinitrobenzene with hydrazine, guanidinium carbonate and 4-aminopyrazole. The compounds were characterized by 1H NMR, 13C NMR, IR and mass spectroscopy. Only compound 2 could be prepared in a suitable crystal and molecular model was determined by X-ray analysis.
View Article and Find Full Text PDFSolvent and temperature effects on H-bonding in crystalline picolinic acid N-oxide (PANO) and in solutions were studied by NMR (H MAS and H-C CP/MAS) and X-ray diffraction (XRD) methods. The single-crystal XRD experiments on β-polymorph were carried out at 105 and 299 K. C chemical shifts of PANO pyridine ring carbons were chosen as an effective diagnostic tool for the H-bond sensing.
View Article and Find Full Text PDFMixtures of the frog peptides magainin 2 and PGLa are well-known for their pronounced synergistic killing of Gram-negative bacteria. We aimed to gain insight into the underlying biophysical mechanism by interrogating the permeabilizing efficacies of the peptides as a function of stored membrane curvature strain. For Gram-negative bacterial-inner-membrane mimics, synergism was only observed when the anionic bilayers exhibited significant negative intrinsic curvatures imposed by monounsaturated phosphatidylethanolamine.
View Article and Find Full Text PDFArticle Synopsis
- A series of pentacoordinate Ni(ii) complexes were synthesized using pentadentate Schiff base ligands derived from aromatic ortho-hydroxy-aldehydes and aliphatic triamines, and their structures were analyzed through X-ray and magnetometric techniques.
- The geometry of these complexes ranged from square-pyramid to trigonal-bipyramid depending on the substituents on the parent ligand, with the trigonal-bipyramidal variants showing significant negative uniaxial anisotropy (D = -64 cm(-1)).
- Despite the notable negative D-values indicating potential for single-molecule magnet behavior, the complexes did not exhibit slow relaxation of magnetization under various magnetic field conditions, suggesting a lack of single-molecule