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A new pyridine-fused selenodiazolium salt, 3-(phenylselanyl)[1,2,4]selenadiazolo[4,5-a]pyridin-4-ylium chloride dichloromethane 0.352-solvate, C12H9-N2Se2+ ·Cl ·0.352CH2Cl2, was obtained from the reaction between 2-pyridylselenenyl chloride and phenylselenocyanate. Single-crystal structural analysis revealed the presence of C—H...N, C—H...Cl, C—H...Se hydrogen bonds as well as chalcogen–chalcogen (Se...Se) and chalcogen–halogen (Se...Cl ) interactions. Non-covalent interactions were explored by DFT calculations followed by topological analysis of the electron density distribution (QTAIM analysis). The structure consists of pairs of selenodiazolium moieties arranged in a head-to-tail fashion surrounding disordered dichloromethane molecules. The assemblies are connected by C—H...Cl and C—H...N hydrogen bonds, forming layers, which stack along the c-axis direction connected by bifurcated Se...Cl- ...H—C interact [ABSTRACT FROM AUTHOR]

A new pyridine-fused selenodiazolium salt, 3-(phenylselanyl)[1,2,4]selenadiazolo[4,5-a]pyridin-4-ylium chloride dichloromethane 0.352-solvate, C12H9N2Se2+·Cl-·0.352CH2Cl2, was obtained from the reaction between 2-pyridylselenenyl chloride and phenylselenocyanate. Single-crystal structural analysis revealed the presence of C--H⋯N, C--H⋯Cl-, C--H⋯Se hydrogen bonds as well as chalcogen-chalcogen (Se⋯Se) and chalcogen-halogen (Se⋯Cl-) interactions. Non-covalent interactions were explored by DFT calculations followed by topological analysis of the electron density distribution (QTAIM analysis). The structure consists of pairs of selenodiazolium moieties arranged in a head-to-tail fashion surrounding disordered dichloromethane molecules. The assemblies are connected by C--H⋯Cl- and C--H⋯N hydrogen bonds, forming layers, which stack along the c-axis direction connected by bifurcated Se⋯Cl-⋯H--C interactions. [ABSTRACT FROM AUTHOR]

1H-Pyridine-2-selenenyl dibromide, C5H5NSeBr2, 1, is a product of the bromination of bis(pyridin-2-yl) diselenide in methylene 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 1.927 (3) A° is typical of a single bond. The virtually linear Br--Se--Br moiety of 178.428 (15)° has symmetrical geometry, with Se--Br bonds of 2.5761 (4) and 2.5920 (4) A°, and is twisted by 63.79 (8)° relative to the pyridinium plane. The Se atom forms an intermolecular Se···Br contact of 3.4326 (4) A°, adopting a distorted square-planar coordination. In the crystal, molecules of 1 are linked by intermolecular N--H···Br and C--H···Br hydrogen bonds, as well as by non-covalent Se···Br interactions, into a three-dimensional framework. (3aSR,(9aRS)-2,3,3a,9a-Tetrahydro-1Hcyclopenta[4,5][1,3]selenazolo[3,2-a]pyridinium-9 bromide, C10H12NSe+·Br-, 2, is a product of the cycloaddition reaction of 1 with cyclopentene. Compound 2 is a salt containing a selenazolopyridinium cation and a bromide anion. Both fivemembered rings of the cation adopt envelope conformations. The dihedral angle between the basal planes of these rings is 62.45 (11)°. The Se atom of the cation forms two additional non-covalent interactions with the bromide anions at distances of 3.2715 (4) and 3.5683 (3) A°, attaining a distorted square-planar coordination. In the crystal, the cations and anions of 2 form centrosymmetric dimers by non-covalent Se···Br interactions. The dimers are linked by weak C--H···Br hydrogen bonds into double layers parallel to (001). [ABSTRACT FROM AUTHOR]

The title compound, C5H4ClNOSe, is the product of the reaction of sulfuryl chloride and 2-selanyl-1-pyridine 1-oxide in dichloromethane. The molecule has an almost planar geometry (r.m.s. deviation = 0.012 Å), and its molecular structure is stabilized by an intramolecular secondary Se⋯O interaction of 2.353 (3) Å, closing a four-membered N--C--Se⋯O ring. The title compound represents the first monomeric organoselenenyl chloride stabilized intramolecularly by an interaction of this type. The non-valent attractive Se⋯O interaction results in a substantial distortion of the geometry of the ipso-carbon atom. The endo-cyclic N--C--Se [102.1 (3)°] and exo-cyclic C--C--Se [136.9 (3)°] bond angles deviate significantly from the ideal value of 120° for an sp²-hybridized carbon atom, the former bond angle being much smaller than the latter. In the crystal, molecules are linked by C--H⋯O hydrogen bonds, forming zigzag chains propagating along [010]. The chains, which stack along the a-axis direction, are linked by offset π-π interactions [intercentroid distance = 3.960 (3) Å], forming corrugated sheets parallel to the ab plane. [ABSTRACT FROM AUTHOR]