4,7-Diphenyl-1,10-phenanthroline methanol hemisolvate

The asymmetric unit of the title compound, C24H16N2·0.5CH3OH, is comprised of two independent bathophenanthroline molecules (systematic name: 4,7-diphenyl-1,10-phenanthroline) and one methanol molecule. The bathophenanthroline molecules are not planar as there is a considerable rotation of all terminal phenyl rings with respect to the central phenanthroline units [dihedral angles in the range 52.21 (12)–62.14 (10)°]. In addition, a non-negligible torsion is apparent in one of the phenanthroline units: the angle between the mean planes of the two pyridine rings is 14.84 (13)°. The methanol solvent molecule is linked to both N atoms of a bathophenanthroline molecule through a bifurcated O—H⋯(N,N) hydrogen bond.

The asymmetric unit of the title compound, C 24 H 16 N 2 Á-0.5CH 3 OH, is comprised of two independent bathophenanthroline molecules (systematic name: 4,7-diphenyl-1,10phenanthroline) and one methanol molecule. The bathophenanthroline molecules are not planar as there is a considerable rotation of all terminal phenyl rings with respect to the central phenanthroline units [dihedral angles in the range 52.21 (12)-62.14 (10) ]. In addition, a non-negligible torsion is apparent in one of the phenanthroline units: the angle between the mean planes of the two pyridine rings is 14.84 (13) . The methanol solvent molecule is linked to both N atoms of a bathophenanthroline molecule through a bifurcated O-HÁ Á Á(N,N) hydrogen bond.  Table 1 Hydrogen-bond geometry (Å , ). Data collection: SMART (Bruker, 2003); cell refinement: SAINT (Bruker, 2003); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEPII (Johnson, 1976); software used to prepare material for publication: SHELXL97.

Related literature
X-Ray diffraction structure determination the new bathophenanthroline solvate was revealed.
All bathophenanthroline phenyl groups presented in this compound show a considerable rotation with respect to the phenanthroline groups. This geometry can be explained by the single bond between the phenanthroline and phenyl rings.
In bathophenanthroline molecule one the phenyl group C1-C5 shows a rotation of 58.04 (11)° with respect to the quasiplanar phenanthroline group C7-C18 whereas the other phenyl group C19-C24 shows a rotation of 52.21 (12)°. In the other bathophenanthroline molecule the angles between the mean plane of the non-planar phenanthroline group C31-C42 and the phenyl groups C25-C30 and C43-C48 are 56.49 (11)° and 62.14 (10)°, respectively. Furthermore, a nonnegligible torsion is observed in one of the phenanthroline groups, the pseudo-torsion angle between C31..C32 and C41..C42 is 17.6 (5)° in the non-planar phenanthroline whereas in the quasi-planar one the angle between C7..C8 and C16..C17 is 4.6 (5)°. A similar torsion has been observed in the structure of the pure bathophenanthroline (Ceolin et al., 1979) The solvent methanol molecules are linked to one of the bathophenanthroline through O-H···N hidrogen bonds (Table   2).
When viewed along the a axis direction (Fig. 2) the packing diagram shows alternating layers. One layer contains the non-planar bathophenanthroline molecules packed so as to maximize π···π interaction between neighbouring molecules.
The Cg2..Cg2 ii distance is 4.5147 (17) Å (Cg2 is the centroid of the six-membered ring containing N4; ii : 1 -x, 1 -y, 1z). The other layer contains the quasi-planar bathophenanthroline molecules linked to the methanol molecules. The angle between the mean planes of the phenanthroline moieties of the quasi-planar and non-planar bathophenanthroline molecules is 32.59 (6)°.

Experimental
First, 0.5 mmol of Europium(III) nitrate pentahydrate was dissolved in 20 ml of methanol, followed by the addition of 0.9 ml of potassium methoxide. This solution was left in reflux at 75°C for 10 minutes. Secondly, 1.5 mmol of 1,14 chlorophenyl-4,4,4-trifluoro-1,3-butanedionate was dissolved in 15 ml of methanol and added to the main solution. After decanting the resultant solution, 0.5 mmol of bathophenanthroline was dissolved in 10 ml of methanol and added to the main solution. The resultant solution was left in reflux at 75°C and 900 rpm for 4 h. After the evaporation process had been completed all the material from this batch was dissolved in 50% of methanol and 50% of chloroform with the intent of obtaining crystals. After the second evaporation process a yellow powder, which is believed to be the target complex was recovered alongside with some light pink crystals and some transparent crystals. The powder has proven to be amorphous while the light pink crystals turned out to be the title complex and the transparent ones potassium nitrate.

Refinement
All hydrogen atoms bound to carbon atoms were placed at calculated positions and were treated as riding on the parent atoms with C-H = 0.93 Å and with U iso (H) = 1.2 U eq (C). The H atom belonging to the OH group was found in a difference electron density synthesis and subsequently refined with a fixed distance (0.82 Å) and angle (109.5°). In the final cycles of refinement, 14 bad outlier reflections, partially attenuated by the beamstop, were omitted.

Computing details
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.