Variation in the Mode of Coordination of Aryl Sulfonates to Zirconocene in the Solid State

The solid-state structures of three zirconocene aryl sulfonates were determined. In Cp2Zr(OSO2C6H5)2 (1), one
of the sulfonate ligands is monodentate, the other bidentate coordinated. Cp2Zr(OSO2-4-C6H4Cl)2 (2) and
Cp2Zr(OSO2-3,4-C6H3Cl2)2 (3) are dimers of pentacoordinated zirconocenes with two monodentate sulfonates
and a double bridge of μ-O,μ-O‘-sulfonates. A possible explanation for the formation of the solid-state structures
is offered in terms of differences in electron density of the sulfonate oxygen atoms. 1:  C22H20O6S2Zr, a =
8.062(2) Å, b = 14.502(3) Å, c = 19.623(4) Å, α = 90.91(1)°, β = 101.78(1)°, γ = 106.00(2)°, triclinic, P1̄, Z
= 4. 2:  C22H18Cl2O6S2Zr, a = 7.9669(8) Å, b = 11.0816(12) Å, c = 13.4056(10) Å, α = 79.944(7)°, β =
75.009(7)°, γ = 84.647(9)°, triclinic, P1̄, Z = 2. 3:  C22H16Cl4O6S2Zr, a = 7.7574(7) Å, b = 12.1124(12) Å, c
= 13.4613(11) Å, α = 85.343(7)°, β = 76.653(6)°, γ = 79.880(8)°, triclinic, P1̄, Z = 2.