Crystal structure of a tetrakis-substituted pyrazine compound: 2,3,5,6-tetrakis(bromomethyl)pyrazine

2020

Self Cite

The title thiapyrazinophanes, 2,5,8,11,14,17-hexathia-[9.9](2,6,3,5)-pyrazinophane, C16H24N2S6, (I), and 2,5,8,11,14,17-hexathia-[9.9](2,5,3,6)-pyrazinophane, C16H24N2S6, (II), are regioisomers; m-bis L1 and p-bis L1, respectively. Both compounds have a central tetra-2,3,5,6-methylenepyrazine unit with two –S—CH2—CH2—S—CH2—CH2—S– chains, linking the methylene C atoms at positions 2 and 6 and 3 and 5 on the pyrazine ring of I, but linking the methylene C atoms at positions 2 and 5 and 3 and 6 on the pyrazine ring of II. Both compounds crystallize with half a molecule in the asymmetric unit. The whole molecule of I is generated by inversion symmetry, with the pyrazine ring being located about a center of symmetry. The whole molecule of II is generated by twofold rotation symmetry, with the pyrazine N atoms being located on the twofold rotation axis. In compound I, there are pairs of intramolecular C—H...S contacts present, but none in compound II. In the crystal of I, there are no significant intermolecular interactions present, while in the crystal of II, molecules are linked by pairs of C—H...S hydrogen bonds, forming corrugated layers lying parallel the ac plane. The Hirshfeld surfaces and the energy frameworks of the two regioisomers indicate little difference in the interatomic contacts, which are dominated by dispersion forces.

Section: Synthesis and Crystallizationmentioning

confidence: 99%

The crystal structures, Hirshfeld surface analyses and energy frameworks of two hexathiapyrazinophane regioisomers; 2,5,8,11,14,17-hexathia-[9.9](2,6,3,5)-pyrazinophane and 2,5,8,11,14,17-hexathia-[9.9](2,5,3,6)-pyrazinophane

2020

Self Cite

“…For syntheses of the starting reagent, 2,3,5,6-tetrakis(bromomethyl)pyrazine, see: Ferigo et al (1994); Assoumatine (1999); Assoumatine & Stoeckli-Evans (2014). For the crystal structures of similar sulfanylmethyl derivatives of pyrazine, such as two triclinic polymorphs of 2,3,5,6 tetrakis(naphthalen-2-ylsulfanylmethyl)pyrazine both possessing inversion symmetry, see: Pacifico & Stoeckli-Evans (2004), and for 2,3,5,6-tetrakis(phenylsulfanylmethyl)pyrazine, which also crystallizes in space group P1 and possesses inversion symmetry, see: Assoumatine et al (2007 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2013 (Sheldrick, 2008); molecular graphics: Mercury (Macrae et al, 2008); software used to prepare material for publication: SHELXL2013, PLATON (Spek, 2009) and publCIF (Westrip, 2010…”

Section: Related Literaturementioning

confidence: 99%

Crystal structure of 2,3,5,6-tetrakis[(methylsulfanyl)methyl]pyrazine

2014

Self Cite

The title compound, C12H20N2S4, synthesized by the reaction of 2,3,5,6-tetrakis(bromomethyl)pyrazine with sodium methanethiolate, crystallizes with a half -molecule in the asymmetric unit. The whole molecule is generated by inversion symmetry; the inversion centre being located in the centre of the pyrazine ring. The molecule has an S-shaped conformation with two (methylsulfanyl)methyl substituent arms directed above the plane of the pyrazine ring and two below. The C(H3)—S—C(H2)—C(aromatic) torsion angles are 70.47 (18) and −67.65 (17)°, respectively. In the crystal, molecules are linked via weak C—H⋯S hydrogen bonds, forming chains along [001] and enclosing R 2 2(12) ring motifs. The chains are linked by further weak C—H⋯S hydrogen bonds, forming sheets lying parallel to (101).

Silver(I) nitrate complexes of three tetrakis-thioether-substituted pyrazine ligands: metal–organic chain, network and framework structures

2017

Self Cite

The reaction of silver nitrate with the ligands 2,3,5,6-tetrakis[(methylsulfanyl)methyl]pyrazine, 2,3,5,6-tetrakis[(phenylsulfanyl)methyl]pyrazine and 2,3,5,6-tetrakis[(pyridin-2-ylsulfanyl)methyl]pyrazine, three tetrakis-thioether-substituted pyrazine ligands, lead, respectively, to the formation of compounds with a metal–organic chain, a metal–organic network and a metal–organic framework structure.