Supramolecular structure of tetrakis-μ-(4-chloro-3-nitrobenzoato)- bis(methanol)dicopper(II)

The title compound, [Cu₂(II)(4-Cl-3-NO₂ - C ₆H₃CO₂)₄(CH₃OH) ₂] or [Cu₂(4-chloro-3-nitrobenzoate)₄(MeOH) ₂] has been prepared and its structure determined using X-ray crystallography. The complex crystallizes in the triclinic space group P-1 with a = 9.6887(9) Å, b = 10.6448(9) Å, c = 11.4194(10) Å, α = 108.094(2), β = 110.682(2), γ = 105.055(2), V = 952.691(15) ų, and Z = 1. The structure consists of centrosymmetric dimers in which the Cu(II) atoms display a square pyramidal CuO₅ coordination, with four carboxylate O atoms in the basal plane [Cu - O 1.951(2)-1.968(2) Å] and the methanol O atoms in the apical position [Cu - O 2.170(2) Å]. The Cu atoms are 2.614(1) Å apart and are bridged by four benzoate groups. The discrete dimers are extended into 1D chains that result from hydrogen bonding between the coordinated methanol on one Cu(II) dimer and the nitro substituent on an adjacent Cu(II) dimer. The chains are interdigited and held by π-π stacking interactions forming 3D supramolecular array.