Two coordination compounds of SnCl2 with 4-methylpyridine N-oxide

In the solid-state structures of catena-poly[[dichloridotin(II)]-μ2-(4-methylpyridine N-oxide)-κ2O:O], [SnCl2(C6H7NO)]n, 1, and dichloridobis(4-methylpyridine N-oxide-κO)tin(II), [SnCl2(C6H7NO)2], 2, the bivalent tin atoms reveal a seesaw coordination with both chlorine atoms in equatorial and the Lewis base molecules in axial positions. While the Sn—Cl distances are almost identical, the Sn—O distances vary significantly as a result of the different bonding modes (μ2 for 1, μ1 for 2) of the 4-methylpyridin-N-oxide molecules, giving rise to a one-dimensional coordination polymer for the 1:1 adduct, 1, and a molecular structure for the 1:2 adduct, 2. The different coordination modes also influence the bonding parameters within the almost planar ligand molecules, mostly expressed in N—O-bond lengthening and endocyclic bond-angle widening at the nitrogen atoms. Additional supramolecular features are found in the crystal structure of 2 as two adjacent molecules form dimers via additional, weak O...Sn interactions.