Silver(I) nitrate two-dimensional coordination polymers of two new pyrazine-thio-phane ligands: 5,7-di-hydro-1H,3H-dithieno[3,4-b:3',4'-e]pyrazine and 3,4,8,10,11,13-hexa-hydro-1H,6H-bis-([1,4]di-thio-cino)[6,7-b:6',7'-e]pyrazine.

ABSTRACT: The two new pyrazine-ophanes, 5,7-di-hydro-1H,3H-dithieno[3,4-b:3',4'-e]pyrazine, C8H8N2S2, L1, and 3,4,8,10,11,13-hexa-hydro-1H,6H-bis-([1,4]di-thio-cino)[6,7-b:6',7'-e]pyrazine, C12H16N2S4, L2, both crystallize with half a mol-ecule in the asymmetric unit; the whole mol-ecules are generated by inversion symmetry. The mol-ecule of L1, which is planar (r.m.s. deviation = 0.008?Å), consists of two sulfur atoms linked by a rigid tetra-2,3,5,6-methyl-ene-pyrazine unit, forming planar five-membered rings. The mol-ecule of L2 is step-shaped and consists of two S-CH2-CH2-S chains linked by the central rigid tetra-2,3,5,6-methyl-ene-pyrazine unit, forming eight-membered rings that have twist-boat-chair con-fig-urations. In the crystals of both compounds, there are no significant inter-molecular inter-actions present. The reaction of L1 with silver nitrate leads to the formation of a two-dimensional coordination polymer, poly[(?-5,7-di-hydro-1H,3H-dithieno[3,4-b;3',4'-e]pyrazine-?2 S:S')(?-nitrato-?2 O:O')silver(I)], [Ag(NO3)(C8H8N2S2)] n , (I), with the nitrato anion bridging two equivalent silver atoms. The central pyrazine ring is situated about an inversion center and the silver atom lies on a twofold rotation axis that bis-ects the nitrato anion. The silver atom has a fourfold AgO2S2 coordination sphere with a distorted shape. The reaction of L2 with silver nitrate also leads to the formation of a two-dimensional coordination polymer, poly[[?33,4,8,10,11,13-hexa-hydro-1H,6H-bis-([1,4]di-thio-cino)[6,7-b;6',7'-e]pyrazine-?3 S:S':S''](nitrato-?O)silver(I)], [Ag(NO3)(C12H16N2S4)] n , (II), with the nitrate anion coordinating in a monodentate manner to the silver atom. The silver atom has a fourfold AgOS3 coordination sphere with a distorted shape. In the crystals of both complexes, the networks are linked by C-H?O hydrogen bonds, forming supra-molecular frameworks. There are additional C-H?S contacts present in the supra-molecular framework of II.

SUBMITTER: Assoumatine T 

PROVIDER: S-EPMC7133031 | biostudies-literature | 2020 Apr

REPOSITORIES: biostudies-literature