2,5,8,11-Tetramethyl-2,5,8,11-tetraazadodecane-2,11-diiumbis[hydroxytris(pentafluorophenyl)- borate]benzene2.5-solvate

The title compound of overall stoichiometry, C12H32N4
 2+·2C18HBF15O−·2.5C6H6, crystallizes in the triclinic space group P\overline{1} and the stoichiometry of the asymmetric unit consists of two [C12H32N4]2+ dications, two [C18HBF15O]− anions, and 2.5 molecules of benzene as solvate. The dications are both at half occupancy and located on a center of inversion, as is one of the benzene solvate molecules. In the two anions the O—H groups participate in different hydrogen-bonding schemes. In anion A, the OH group participates in a bifurcated 2R
 2
 2(6) scheme with F atoms on different rings of an adjacent hydroxy[tris(pentafluorophenyl)]borate moiety with an additional N—H...O hydrogen bond with a dication. For anion B, the OH group participates in a single O—H...F R
 2
 2(6) scheme. In addition, there are both O—H...N and N—H...O hydrogen bonds involving dication D and anion B in an R
 2
 2(7) motif. There are numerous C—H...π interactions between the dications and all the three benzene solvate molecules. For solvate 3, the C—H...π interactions are on both sides of the benzene ring and link both dications and solvate into a linear chain in the c-axis direction.

The title compound of overall stoichiometry, C 12 H 32 N 4 2+ Á2C 18 HBF 15 O À Á-2.5C 6 H 6 , crystallizes in the triclinic space group P1 and the stoichiometry of the asymmetric unit consists of two [C 12 H 32 N 4 ] 2+ dications, two [C 18 HBF 15 O] À anions, and 2.5 molecules of benzene as solvate. The dications are both at half occupancy and located on a center of inversion, as is one of the benzene solvate molecules. In the two anions the O-H groups participate in different hydrogenbonding schemes. In anion A, the OH group participates in a bifurcated 2R 2 2 (6) scheme with F atoms on different rings of an adjacent hydroxy[tris(pentafluorophenyl)]borate moiety with an additional N-HÁ Á ÁO hydrogen bond with a dication. For anion B, the OH group participates in a single O-HÁ Á ÁF R 2 2 (6) scheme. In addition, there are both O-HÁ Á ÁN and N-HÁ Á ÁO hydrogen bonds involving dication D and anion B in an R 2 2 (7) motif. There are numerous C-HÁ Á Á interactions between the dications and all the three benzene solvate molecules. For solvate 3, the C-HÁ Á Á interactions are on both sides of the benzene ring and link both dications and solvate into a linear chain in the c-axis direction.

Figure 2
Diagram showing the structure of the [C 12  HÁ Á ÁN and N-HÁ Á ÁO hydrogen bonds involving cation D and anion B in a R 2 2 (7) motif. While this structure contains numerous phenyl rings, there does not appear to be anystacking. The closest is for the ring C7A-C12A with itself (symmetry code 1 À x, 2 À y, Àz) where the CgI_Perp distance is 2.8921 (15) Å but the slippage is 4.685 Å so there appears to be no stacking. However, there are numerous C-HÁ Á Á interactions between the cations and all the three benzene solvate molecules (see Fig. 3). For solvate 3, the C-HÁ Á Á interactions are on both sides of the benzene ring and link both cation and solvate into a linear chain in the c-axis direction (see Fig. 4). The packing is shown in Fig. 5.

Synthesis and crystallization
In a reaction bulb, hexamethyltriethylenetetramine (0.050 g, 0.22 mmol) was mixed with tris(pentafluorophenyl)borane (0.44 g, 0.86 mmol) in $10 mL dry toluene in an argon-filled drybox. A yellowish brown mixture with two liquid phases resulted. On a vacuum line, the mixture was frozen and 1.72 mmol CO 2 was condensed in. After a day, solids began to form and the reaction was continued for several weeks. Some of the solids were flame sealed in an NMR tube with C 6 D 6 , but it was not soluble enough to obtain a spectrum. When the NMR tube was opened, crystals of the title compound were isolated. The oxygen atom must have come from the CO 2 and the proton must have come from either the toluene or the amine.

Refinement
Crystal data, data collection and structure refinement details are summarized in Table 2. Diagram showing how the C-HÁ Á Á interactions between the third benzene solvate molecule and cation C.

Figure 5
Packing diagram of the title compound.  where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max < 0.001 Δρ max = 0.30 e Å −3 Δρ min = −0.39 e Å −3 Special details Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.