Crystal structure of catena-{2,2'-[butylene-1,4-dithio]bis(5-methyl- 1,3,4-thiadiazole)}bis(2,4,6-trinitrophenolate)copper(II), Cu(C10H14S4N4)(C6H2N3O7)2

Abstract

Source of materialThe reaction of 2,2'-[butylene-1,4-dithio]bis(5-methyl-1,3,4-thiadiazole) (0.1 mmol) with Cu(Pic) 2 × 4H 2 O( 0.1 mmol) in MeOH (10 mL)for afew minutes afforded alight blue solid. It was filtered, washed with acetone, and dried in air. Thes ingle crystals suitable for X-ray analysis were obtained by slow diffusion of Et 2 Ointo the acetonitrile solution of the solid. DiscussionMetal-organic frameworks (MOFs) are continuously studied because of their intriguing structural architectures and topologies, as well as their potential applications as functional materials in the fields of nonlinear optics, magnetism,molecular separation, catalysis, luminescence, and gas sorption [1,2]. In principle, the most effective approach for the construction of MOFs is to rationally modify the building blocks and to control the assembled motifs for required products via selecting appropriate organic ligands [3][4][5].Theflexiblebisthiadiazolealkanes, as 2,2'-[butylene-1,4-dithio]-bis(5-methyl-1,3,4-thiadiazole), bearing alkyl spacer (-CH 2 -) 4 , are good candidates for N-donor linkers [6,7].The flexible nature of the (-CH 2 -) 4 spacer allows the molecules to bend and rotate freely when binding to metal centers and adjust to the coordinative ability of metal ions. The asymmetric unit of the title crystal structure consists of ahalf Cu 2+ ion, ah alf 2,2'-[butylene-1,4-dithio]bis(5-methyl-1,3,4-thiadiazole) ligand, and one 2,4,6-trinitrophenolate (picrate) ligand. Each Cu 2+ ion is six-coordinated with a{ CuN 2 O 4 }d istorted octahedral environment. Four oxygen atomsf rom two picrate ligands occupy the equatorial plane (d(Cu1-O1) = 1.931(2) Åa nd d(Cu1-O7) =2 .5789(7) Å). Nitrogen atoms from two thiadiazole ligands occupy the apical sites (d(Cu1-N4) =1 .995(2) Å). All Cu-O and Cu-N bond distances are within the range expected for such bonds [6,7]. Obviously, only the Natoms of the thiadiazole ligands coordinate to Cu 2+ ion. The thiadiazole ligands adopt a N,N-bidentate bridging mode in trans configuration for bridging the Cu 2+ ions via translationsymmetry into one-dimensional chains, with the bridged distance d(Cu-Cu)=1 2.176(3) Å. These chains aref urther interconnected with neighbouring molecules by weak intermolecular N-O×××p interactions and C-H×××Oh ydrogen bonds to generate athree-dimensional network. The centroid separation of thiadiazole rings is 9.401(3) Å. Thep icrate ligand adopts bidentate-chelating coordination mode and serves to complete the coordination sphere of the Cu 2+ ion.