4-Chloroanilinium tetrafluoroborate 18-crown-6 clathrate

In the title compound, C6H7ClN+·BF4 −·C12H24O6, the complete cation is generated by crystallographic mirror symmetry, with two C atoms and the N and Cl atoms lying on the mirror plane. The complete crown ether is also generated by mirror symmetry, as is the anion (in which the B and two F atoms lie on the mirror plane). The –NH3 + group of the cation inserts into the crown-ether ring and forms bifurcated N—H⋯(O,O) hydrogen bonds. The H atoms of the –NH3 + group were modelled as disordered across the mirror plane.

In the title compound, C 6 H 7 ClN + ÁBF 4 À ÁC 12 H 24 O 6 , the complete cation is generated by crystallographic mirror symmetry, with two C atoms and the N and Cl atoms lying on the mirror plane. The complete crown ether is also generated by mirror symmetry, as is the anion (in which the B and two F atoms lie on the mirror plane). The -NH 3 + group of the cation inserts into the crown-ether ring and forms bifurcated N-HÁ Á Á(O,O) hydrogen bonds. The H atoms of the -NH 3 + group were modelled as disordered across the mirror plane.

Related literature
For the ferroelectric properties of related compounds, see: Fu et al. (2011) Experimental Crystal data  Table 1 Hydrogen-bond geometry (Å , ). With the purpose of obtaining phase transition crystals of amino compounds, various amines have been studied and we have elaborated a series of new materials with this organic molecules (Fu et al. 2011). In this study, we describe the crystal structure of the title compound.
The asymmetric unit is composed of one organic cation, one BF 4anion and one crown ether (Fig.1). The 4-chloroanilium cation and macrocyclic ether mlecule are associated vis hydrogen bonding with the -NH 3 + group forming bifurcated bonds with all six O atoms of 18-crown-6 molecule. Despite the disorder in the amino group, it is clear that in each orientation the cation forms three bifurcated hydrogen bonds. These H-bonding interactions link the cation and 18crown-6 ether molecule into a 1:1 complex, [(C 6 H 7 ClN).(18-rown-6)] + (Table 1 and Fig.2).

Experimental
18-Crown-6 (3 mmol), HBF 4 (5 mmol) and the organic amine (3 mmol) were dissolved in water/EtOH (1: The solvent was slowly evaporated in air affording colourless block-shaped crystals of the title compound. The dielectric constant of title compound as a function of temperature indicates that the permittivity is basically temperature-independent, suggesting that this compound should be not a real ferroelectrics or there may be no distinct phase transition occurred within the measured temperature range. Similarly, below the melting point (405 K) of the compound, the dielectric constant as a function of temperature also goes smoothly, and there is no dielectric anomaly observed (dielectric constant ranging from 4.1 to 8.1).

Refinement
All H atoms attached to C atoms were fixed geometrically and treated as riding with C-H = 0.93 Å (Caromatic) or 0.97 Å (Cmethylene).
The positional parameters of the H atoms (N1) were intially refined freely, subsequently restrained using a distance of N-H = 0.89 (2) Å, and in the final refinements treated in riding motion of their parent nitrogen atom with    Chloroanilinium tetrafluoroborate 1,4,7,10,13 where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max < 0.001 Δρ max = 0.24 e Å −3 Δρ min = −0.26 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. 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 > 2sigma(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. (