1,3,5-Tris(4-bromophenyl)-1,3,5-triazinane dichloromethane monosolvate

In the main molecule of the title compound, C21H18Br3N3·CH2Cl2, the triazinane ring adopts a chair conformation with three 4-bromophenyl substituents, two in diaxial positions and the third in an equatorial arrangement (eaa). The torsion angles around the N—C bonds in the triazinane ring are in the range 55.6 (5)–60.1 (5)°. The structure can be described as being built up of alternating layers along the b axis with the CH2Cl2 solvent molecules sandwiched between these layers. No classical hydrogen-bonding interactions are observed in the crystal structure.

In the main molecule of the title compound, C 21 H 18 Br 3 N 3 Á-CH 2 Cl 2 , the triazinane ring adopts a chair conformation with three 4-bromophenyl substituents, two in diaxial positions and the third in an equatorial arrangement (eaa). The torsion angles around the N-C bonds in the triazinane ring are in the range 55.6 (5)-60.1 (5) . The structure can be described as being built up of alternating layers along the b axis with the CH 2 Cl 2 solvent molecules sandwiched between these layers. No classical hydrogen-bonding interactions are observed in the crystal structure.

Related literature
For the conformations of 1,3,5-triaryl derivatives of 1,3,5-triazacyclohexane, see: Wellington & Tollens (1885); Bouchemma et al. (1988); Adam et al. (1993); Gilardi et al. is axial, are possible and each of these conformations results in axial interactions involving substituents or lone pair of electrons on the N atoms. X-ray investigation of 1,3,5-triazacylohexane of 1,3,5-trialkyl and 1,3,5-triarylderivatives of 1,3,5-triazacyclohexane have consistently found the expected chair conformation with pyramidal arrangement of bonds at N atoms (Wellington & Tollens, 1885;Bouchemma et al., 1988;Adam et al., 1993;Gilardi et al., 2003). In the course of our studies in similar compounds we report here a conformation and crystal structure a new derivate of l,3,5-triazacylohexane, it is the product of a condensation reaction between 4-bromoaniline and formaldehyde. The molecular geometry and the atom-numbering scheme of (I) are shown in Fig. 1. The 1,3,5-tris(p-bromorophenyl)-l,3,5-triazacylohexane, adopts a chair conformation with two p-bromophenyl substituents situated in axial positions and a third in equatorial agreement (eaa). The structure can be described as alternating layers parallel to (010)planes, along the b axis and the dichloromethane solvent molecules are sandwiched between these layers (Fig.2). The packing of (I) is stabilized by a Van Der Waals interactions which form a three-dimensional network. No classical hydrogen bond was found.
Stirring was then maintained at 25°C for 12 h. The precipitate thus formed was then collected and washed with diethyl ether. The residue was crystallized from dichloromethane.

Refinement
All non-H atoms were refined with anisotropic atomic displacement parameters. All H atoms were localized on Fourier maps but introduced in calculated positions and treated as riding on their parent C atom, with C-H distances of 0.93 Å (C aromatic ) and 0.97 Å (C methylene ) and with U iso (H) = 1.2 U eq (C aromatic and C methylene ).   A diagram of the layered crystal packing in (I), viewed down the a axis.

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.