Július Sivý

The crystal structure of butylchlorobis(8-quinolinate)tin(IV)

Abstract A single crystal X-ray diffraction study has shown that in butyl-chloro-bis(8-quinolinate)tin(IV) the coordination geometry around the tin atom is distorted octahedral; two O atoms, a N atom of the cis -chelated 8-quinolinate ligands, and a chlorine atom are in equatorial sites. The apical sites are occupied by the N atom of the other cis -chelate 8-quinolinate group and the butyl group. The apical groups form a CSnN angle of 172.3(2)°. The two SnO distances are effectively equal [2.054(4) A and 2.059(3) A], but the axial SnN bond [2.223(5) A] is slightly longer than the equatorial SnN bond [2.201(4) A]. The SnCl and SnC distances [2.429(2) A; 2.073(6) A] are similar to those in related complexes.

Structure of dibenzylchlorotin(IV) thiooxinate

The structure of dibenzylchloro(8-quinolinethiolato-N,S)tin(IV) consists of monomeric trigonal bipyramidal chelate molecules. The two benzyl C atoms and the thiooxinate S atom occupy equatorial sites; the N atom of the bidentate thiooxinate group [Sn-N 2.367 (4) A] and the Cl atom [Sn-Cl 2.475 (2) A] are axial. The strong Sn-N bond causes deformation of the coordination polyhedron and is a consequence of electronic effects of the thiooxinate group and steric effects of the benzyl substituents

Derivatives of (4R)-1,3-thiazolidine-4-carboxylic acid labeled with technetium-99m

The preparation of99mTc-complexes with nine derivatives of (4R)-1,3-thiazolidine-4-carboxylic acid over a broad pH range is described. The labeling efficiency of all compounds was checked by paper- and thin layer chromatography. Paper electrophoresis and gel chromatography indicated the presence of two types of99mTc-complexes differing in charge and molecular size. Preliminary results of the biodistribution of anionic complexes in mice are given. The structure of both types of the Tc-complexes is also discussed.

2-Acetyl-3-(5-cyano-2-furyl)propenenitrile

The crystal structure of the title compound, C 10 H 6 N 2 O 2 , : consists of relatively isolated molecules, the shortest intermolecular contacts [C-H...O 2.51 (2); C-H...N 2.50(1) and 2.60(2)A] indicate the presence of weak hydrogen bonding. As indicated by the planarity of the molecule and the pattern of bond lengths, the π-electron delocalization extends over the whole molecule.

Crystal and electronic structure, N–H⋯N and C–H⋯O interactions in novel spiro-[chroman-chromene]-carboxylate

Abstract We report here the structure of new spiro-derivative, namely methyl (2R,4R)-4-(5-methylthiazol- 2-ylamino)spiro[chroman-2,2’-chromene]-3’-carboxylate, C23H20N2O4S, which crystallizes as racemate in the space group P-1. In this compound, the chromanone moiety consists of a benzene ring fused with a sixmembered heterocyclic ring which adopts a distorted half-chair conformation. The molecules are linked by a combination of N–H⋯N hydrogen bonds and weak C–H⋯O, C-H⋯S, C-H⋯π, inter- and intramolecular interactions resulting in a two-dimensional network in the crystal structure.

Crystallographic characterization of a novel spiro-[chroman-chromene]-carboxylate

Abstract We report here the crystal and electronic structure of a new spiro-derivative, namely methyl (2R,4S)- 4-(benzothiazol-2-ylamino)-8,8´-dimethoxyspiro[chroman-2,2´-chromene]-3´-carboxylate (I), C28H24N2O6S, which crystallizes as racemate in the space group C2/c. In this compound, the chromanone moiety consists of a benzene ring fused with a six-membered heterocyclic ring which adopts a distorted half-chair conformation. The molecules are linked by a combination of N-H∙∙∙N hydrogen bonds and weak C-H∙∙∙O, C-H∙∙∙S, C-H∙∙∙ π, inter- and intra-molecular interactions resulting in a two-dimensional network in the crystal structure.

Crystal, molecular and electronic structure of (3aS,4S,9aS,9bR)-4-ethyl-2,2-dimethylhexahydro-[1,3]dioxolo[4,5-g] indolizin-7(3aH)-one

Abstract Molecules of the title compound, C13H21NO3, crystallize as single enantiomers with four stereogenic centres, their absolute configuration were confirmed by anomalous dispersion effects determined by diffraction measurements on the crystals. Conformations of the pyrrolidine and 1,3-oxolane rings are close to that of an envelope, with the flap atoms displaced by −0.205 (1) and −0.449 (1) Å, respectively, from the plane of the other remaining four atoms. The central six-membered ring of the indolizine moiety adopts a nearly perfect boat conformation, with two atoms displaced by 0.575 (1) and 0.603 (1) Å from the plane of the other remaining four atoms. Crystal structure of the title compound is stabilized by C−H···O hydrogen interactions.

Electronic structure, novel synthesis, and O-H...O and C-H...O interactions in two 6-oxopiperidine-2-carboxylic acid derivatives.

Molecules of (S)-6-oxo-1-(thiophen-2-ylmethyl)piperidine-2-carboxylic acid, C11H13NO3S, crystallize as single enantiomers in the space group P21 and the thiophene ring is disordered over two positions, while (S)-6-oxo-1-(thiophen-3-ylmethyl)piperidine-2-carboxylic acid, C11H13NO3S, crystallizes as a single enantiomer in the space group P212121. Their absolute configurations were confirmed by anomalous dispersion effects in diffraction measurements on the crystals. The molecules of each compound are linked by a combination of strong O-H...O hydrogen bonds and weak C-H...O interactions, resulting in two- and three-dimensional networks, respectively, in the crystal structures.

Crystal, molecular and electronic structure of (5S,8aS)-5-methyl-4,6,7,8,8a,9-hexahydrothieno-[ 3,2-f] indolizinium iodide

Abstract The molecules of the title compound, C11H16NS·I, crystallize as single enantiomer with two stereogenic centre, their absolute configuration were confirmed by anomalous dispersion effects in diffraction measurements on the crystals. The conformation of the pyrrolidine ring is close to that of an envelope, with the flap atom N1 displaced by 0.661 (2) A from the plane of the oder remaining four atoms. The central six-membered ring of the indolizine moiety adopt a half-chair conformation with atom C5 displaced by -0.686 (2) Å from the plane of the oder remaining five atoms. The crystal structure of the title compound is stabilized by C-H···I···H-C hydrogen interactions.

(8aR,9R)-9-Hy-droxy-7,8,8a,9-tetra-hydro-furo[3,2-f]indolizin-6(4H)-one.

The title compound, C10H11NO3, crystallizes with four independent molecules in the asymmetric unit. Their geometries are very similar and corresponding bond distances are almost identical. The central six-membered ring of the indolizine moiety adopts a envelope conformation [the displacement of the flap atom (the C atom opposite the N atom) being 0.539 (2), 0.548 (3), 0.509 (3) and 0.544 (3) Å in the four molecules], while the conformation of the oxopyrrolidine ring is close to that of a flat envelope. The displacements of the non-fused C atom opposite the C=O group of the pyrrolidine ring of the four molecules are 0.366 (3), 0.335 (3), 0.173 (3) and −0.310 (3) Å. In the crystal, O—H⋯O hydrogen bonds link the molecules into chains, which run parallel to the c axis. The absolute configuration was assigned from the synthesis.