Mol-ecular and crystal structure of catena-poly[1-benzyl-[1,2,4]triazolo[1,5-c]quinazolin-1-ium-2,5-bis-(thiol-ate) [[aqua-sodium]-di-μ-aqua]].

In the crystal structure of the title salt, {[Na(H2O)3](C16H11N4S2)} n , the 1-benzyl-[1,2,4]triazolo[1,5-c]quinazolin-1-ium-2,5-bis-(thiol-ate) anion is not included in the coordination sphere of the sodium cation. The latter is coordinated by five water mol-ecules, two pairs of which form bridges with two neighbouring sodium cations, whilst the fifth water mol-ecule additionally coordinates monodentately. The anion structure can be described as a superposition of two zwitterionic structures with two negative charges located on the sulfur atoms and one positive charge either on the nitro-gen nodal atom or on the nitro-gen atom bonded to the benzyl group. In the crystal structure, the organic mol-ecules are linked to the aqua ligands via inter-molecular O-H⋯(N,S) hydrogen bonds. The crystal packing can be characterized as layered, defining a three-layer unit parallel to (100) as the main motif. The central part of the three-layer unit consists of 1 ∞[Na(H2O)1/1(H2O)4/2] chains extending parallel to [010]. Two layers of anion mol-ecules sandwich the cation layer.