Di‐μ‐chlorido‐bis[chlorido(η2‐ethene)platinum(II)]

Zeise's dimer, [Pt2Cl4(C2H4)2)], consists of two independent dimeric molecules in the unit cell, one of which is crystallographically centrosymmetric. All Pt atoms are essentially square planar with bridging and trans terminal chloride groups. The ethene groups are orthogonal to the molecular square plane. In the non‐centrosymmetric molecule, the two square planes subtend an angle of 160.10 (13)° at the bridging Cl atoms. The crystal structure exhibits layers of molecules running approximately parallel to the (001) face, with a layer of the centrosymmetric dimer stacked directly between two layers of the non‐centrosymmetric molecules [Pt...Pt = 4.053 (1) and 4.090 (1) Å]. Within this stack, the ethene groups of the central molecule are located betwen two terminal chloride groups of the adjacent molecules. Adjacent three‐layer sandwiches are staggered from each other so that stacking occurs for only one square plane, disrupting any further interaction by one Pt atom but allowing a weaker Pt...Pt interaction [4.249 (1) Å]. The non‐centrosymmetric molecule layer exhibits a weak hydrogen bond between a terminal chloride and an ethene H atom of an adjacent molecule.