Bis(1,10-phenanthroline-κ2 N,N′)(sulfato-O)copper(II) butane-2,3-diol monosolvate

The title compound, [Cu(SO4)(C12H8N2)2]·C4H10O2, is comprised of neutral monomeric complex and butane-2,3-diol solvent molecules. In the complex, the CuII ion is in a distorted square-pyramidal coordination environment defined by four N atoms from two chelating 1,10-phenanthroline ligands and one O atom from a monodentate sulfate anion; the O atom is at the apex. The two chelating N2C2 groups subtend a dihedral angle of 85.8 (4)°. In the crystal, the neutral monomeric complex and butane-2,3-diol solvent molecules are held together by O—H⋯O hydrogen bonding, which leads to additional stabilization of the structure. The presence of pseudosymmetry in the structure suggests the higher symmetry space group C2/c, but attempts to refine the structure in this space group resulted in an unsatisfactory model and high R and wR values. The sulfate anion is disordered over two sets of sites with occupancies of 0.55 (1) and 0.45 (1).

The title compound, [Cu(SO 4 )(C 12 H 8 N 2 ) 2 ]ÁC 4 H 10 O 2 , is comprised of neutral monomeric complex and butane-2,3-diol solvent molecules. In the complex, the Cu II ion is in a distorted square-pyramidal coordination environment defined by four N atoms from two chelating 1,10-phenanthroline ligands and one O atom from a monodentate sulfate anion; the O atom is at the apex. The two chelating N 2 C 2 groups subtend a dihedral angle of 85.8 (4) . In the crystal, the neutral monomeric complex and butane-2,3-diol solvent molecules are held together by O-HÁ Á ÁO hydrogen bonding, which leads to additional stabilization of the structure. The presence of pseudosymmetry in the structure suggests the higher symmetry space group C2/c, but attempts to refine the structure in this space group resulted in an unsatisfactory model and high R and wR values. The sulfate anion is disordered over two sets of sites with occupancies of 0.55 (1) and 0.45 (1).

Experimental
Crystal data [Cu(SO 4   The X-ray diffraction experiment found that the title complex is isotypical to the previously reported  Table 1).
In the crystal, the sulfate group is disordered over two positions with refined site occupancies of 0.55 (1) and 0.45 (1), and is hydrogen bonded to the solvent butane-2,3-diol molecule ( Table 2 & Fig. 1).

Experimental
The single crystals of (I) suitable to X-ray analysis were obtained by 0.2 mmol phen, 0.1 mmol CuSO 4 .5H 2 O, 2.0 ml propane-1,3-diol and 1.0 ml water mixed and placed in a thick Pyrex tube, which was sealed and heated to 453 K for 72 h.

Refinement
The H atoms of phen were positioned geometrically and allowed to ride on their parent atoms, with C-H = 0.93 Å and U iso (H) = 1.2U eq (C). The H atoms of propane-1,3-diol were placed in geometrically idealized positions and refined as riding atoms, with C-H(CH 3 ) = 0.96 Å, C-H(CH) = 0.98 Å and O-H = 0.82 Å; U iso (H) = 1.2U eq (C) and 1.5U eq (O).
The presence of pseudo-symmetry in the structure suggests a higher symmetry space group C2/c. But attempts to refine the structure in the space group C2/c resulted in an unsatisfactory model and high R and wR values. Hence the requirement to solve in Cc. The reported Flack parameter was refined as s full least-squares and obtained by TWIN/BASF procedure in SHELXL (Sheldrick, 2008).

Figure 1
The molecular structure showing the atom-numbering scheme and with displacement ellipsoids drawn at the 35% probability level. Hydrogen bonds O-H···O are shown as dashed lines.   (2) 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 Occ.