Crystal structure analysis, Hirshfeld surface analysis and DFT calculations of a one-dimensional neutral manganese(II) coordination polymer [(CH 3 ) 3 NH][MnCl 2 (H 2 O) 2 ]Cl

The crystal structure of trimethylammonium manganese(II) chloride dihydrate or catena -poly[trimethylammonium [[diaquamanganese(II)]-di-μ-chlorido] chloride], {[(CH 3 ) 3 NH][MnCl 2 (H 2 O) 2 ]Cl} n ( 1 ), originally reported by Caputo et al. (1976). Acta Cryst. B 32 , 2639–2642], has been redetermined at 100 K. The structure retains the orthorhombic space group Pnma and the coordination connectivity of the previously reported room-temperature structure. Each Mn II ion lies on an inversion centre and is coordinated by four bridging chloride ligands and two mutually trans water molecules. The resulting edge-sharing MnCl 4 (H 2 O) 2 octahedra form neutral chains parallel to the b axis, with trimethylammonium cations and non-coordinating chloride anions situated between the chains. The measured unit-cell parameters, bond lengths and bond angles are in good agreement with the room-temperature determination reported by Caputo et al . In the crystal, O—H...Cl and N—H...Cl contacts link the inorganic and organic components. Hirshfeld surface analysis identifies H...Cl/Cl...H contacts as the largest surface-area contribution. Crystal morphology predictions and periodic density functional theory (DFT) calculations provide supplementary descriptions of the crystal habit and electronic response.