RESUMO
New unsymmetrical monoterpenylhetaryl disulfides based on heterocyclic disulfides and monoterpene thiols were synthesized for the first time in 48-88% yields. Hydrolysis of disulfides with fragments of methyl esters of 2-mercaptonicotinic acid was carried out in 73-95% yields. The obtained compounds were evaluated for antioxidant, antibacterial, antifungal activity, cytotoxicity and mutagenicity.
Assuntos
Dissulfetos , Compostos de Sulfidrila , Antifúngicos/farmacologia , Antioxidantes/farmacologia , Ésteres , MutagênicosRESUMO
Correction for 'Novel cationic 1,2,4-selenadiazoles: synthesis via addition of 2-pyridylselenyl halides to unactivated nitriles, structures and four-center Seâ¯N contacts' by Victor N. Khrustalev et al., Dalton Trans., 2021, 50, 10689-10691, DOI: 10.1039/D1DT01322J.
RESUMO
2-Pyridylselenyl halides undergo facile coupling with a triple CN bond of unactivated nitriles. Unprecedented heterocyclization allowed the preparation of a novel class of cationic 1,2,4-selenadiazoles in remarkably high yields. Cationic 1,2,4-selenadiazoles form supramolecular dimers in the crystal via SeN chalcogen bonding, which was studied theoretically.
RESUMO
1H-Pyridine-2-selenenyl dibromide, C5H5NSeBr2, 1, is a product of the bromination of bis-(pyridin-2-yl) diselenide in methyl-ene chloride recrystallization from methanol. Compound 1 is essentially zwitterionic: the negative charge resides on the SeBr2 moiety and the positive charge is delocalized over the pyridinium fragment. The C-Se distance of 1.927â (3)â Å is typical of a single bond. The virtually linear Br-Se-Br moiety of 178.428â (15)° has symmetrical geometry, with Se-Br bonds of 2.5761â (4) and 2.5920â (4)â Å, and is twisted by 63.79â (8)° relative to the pyridinium plane. The Se atom forms an inter-molecular Seâ¯Br contact of 3.4326â (4)â Å, adopting a distorted square-planar coordination. In the crystal, mol-ecules of 1 are linked by inter-molecular N-Hâ¯Br and C-Hâ¯Br hydrogen bonds, as well as by non-covalent Seâ¯Br inter-actions, into a three-dimensional framework. (3aSR,(9aRS)-2,3,3a,9a-Tetra-hydro-1H-cyclo-penta[4,5][1,3]selenazolo[3,2-a]pyridinium-9 bromide, C10H12NSe+·Br-, 2, is a product of the cyclo-addition reaction of 1 with cyclo-pentene. Compound 2 is a salt containing a selenazolopyridinium cation and a bromide anion. Both five-membered rings of the cation adopt envelope conformations. The dihedral angle between the basal planes of these rings is 62.45â (11)°. The Se atom of the cation forms two additional non-covalent inter-actions with the bromide anions at distances of 3.2715â (4) and 3.5683â (3)â Å, attaining a distorted square-planar coordination. In the crystal, the cations and anions of 2 form centrosymmetric dimers by non-covalent Seâ¯Br inter-actions. The dimers are linked by weak C-Hâ¯Br hydrogen bonds into double layers parallel to (001).
RESUMO
The title compound, C10H12Cl3NTe, crystallizes with two crystallographically independent mol-ecules (A and B) in the asymmetric unit. In each case, the coordination around the Te atom is distorted square-pyramidal, with the equatorial plane composed of the three Cl atoms and the C atom of the pyridinium ring. The Te atom is displaced from the mean-square plane by 0.1926â (7) and 0.1981â (8)â Å, in mol-ecules A and B, respectivly, away from the apical C atom. The bond lengths from the Te atom to the two Cl atoms arranged trans to each other [2.5009â (7)/2.5145â (7) and 2.5184â (7)/2.5220â (8)â Å in mol-ecules A and B, respectivly] are substan-ti-ally shorter than the third Te-Cl distance [2.8786â (7) and 2.8763â (7)â Å in mol-ecules A and B, respectivly]. The 1,3-tellurazole ring is almost planar (r.m.s. deviations of 0.042 and 0.045â Å in mol-ecules A and B, respectivly). The cyclopentane rings in both molecules A and B adopt envelope conformations with the carbon atom opposed to the (Te)C-C(N) bond as the flap. In the crystal, mol-ecules form centrosymmetric 2 + 2 associates via Teâ¯Cl inter-actions [3.3993â (7) and 3.2030â (7)â Å]. As a result of these secondary inter-actions, the Te atom attains a strongly distorted 5 + 1 octa-hedral environment. Further, the 2 + 2 associates are bound by weak C-Hâ¯Cl hydrogen bonds into a three-dimensional framework.