Poly[[(methanol)(μ4-2,4,5,6-tetrafluorobenzene-1,3-dicarboxylato)copper(II)] methanol monosolvate]

In the title compound, {[Cu(C8F4O4)(CH3OH)]·CH3OH}n, two CuII atoms are bridged by four carboxylate groups, forming the well known paddle-wheel secondary building unit (SBU) with axial methanol ligands. In each ligand, the dihedral angles between the benzene ring and the two carboxylate groups are 80.43 (17) and 62.5 (4)°. Within each SBU, the four carboxylate groups come from four symmetry-equivalent tetrafluoroisophthalate ligands. Each tetrafluoroisophthalate group connects two SBUs, forming a layered structure . In the crystal, O—H⋯O hydrogen bonds involving the free and ligated methanol molecules link the molecules into a three-dimensional supramolecular network.

In the title compound, {[Cu(C 8 F 4 O 4 )(CH 3 OH)]ÁCH 3 OH} n , two Cu II atoms are bridged by four carboxylate groups, forming the well known paddle-wheel secondary building unit (SBU) with axial methanol ligands. In each ligand, the dihedral angles between the benzene ring and the two carboxylate groups are 80.43 (17) and 62.5 (4) . Within each SBU, the four carboxylate groups come from four symmetryequivalent tetrafluoroisophthalate ligands. Each tetrafluoroisophthalate group connects two SBUs, forming a layered structure . In the crystal, O-HÁ Á ÁO hydrogen bonds involving the free and ligated methanol molecules link the molecules into a three-dimensional supramolecular network.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: PK2400). (CH 3 OH)].CH 3 OH} n , which is constructed using the paddlewheel SBU Cu 2 (O 2 CR) 4 L 2 (L=CH 3 OH).
The asymmetric unit is composed of one Cu II center, one tetrafluoroisophthalate anion, one coordinated methanol ligand, and one methanol solvent molecule (Fig. 1). Each Cu II ion is five-coordinated by four oxygen donors from four different tetrafluoroisophthalate ligands and one oxygen atom from a terminal methanol molecule. In the paddlewheel SBU, the two copper ions are separated by 2.6622 (6) Å. Each SBU connects four tetrafluoroisophthalate ligands, and each tetrafluoroisophthalate group connect two SBUs to form a two dimensional layered structure (Fig. 2). Adjacent parallel layers are connected by O-H···O hydrogen bonds between guest methanol molecules and the coordinated methanol molecules to create a three-dimensional supramolecular network.
After two weeks, blue block-shaped crystals of the title compound suitable for X-ray diffraction were obtained by slow diffusion of the solvents in 26% yield (9.5 mg, based on the ligand).

Figure 1
An ellipsoid plot (30% probability level) of the paddlewheel SBU showing the labelled asymmetric unit. Hydrogen atoms are drawn as small arbitrary spheres.

Special details
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq