N,N-Bis(2-pyridylmethyl)-tert-butylamine

In the title compound, C16H21N3, the dihedral angle between the two pyridine rings is 88.11 (9)°. In the crystal, molecules are linked through intermolecular C—H⋯π interactions, forming a layer expanding parallel to the (10) plane.

In the title compound, C 16 H 21 N 3 , the dihedral angle between the two pyridine rings is 88.11 (9) . In the crystal, molecules are linked through intermolecular C-HÁ Á Á interactions, forming a layer expanding parallel to the (101) plane.
The crystal structure of the title compound ( Fig. 1) shows that the three nitrogen atoms (one sp 3 and two pyridine sp 2 ) are not suitability orientated for pincer-like coordination to a metal. Rotation about the C2-C3 and C8-C9 bonds are required for that to occur. The relative orientation of the two pyridine rings is reflected in a dihedral angle between their mean planes of 88.11 (9)°, clearly this angle would have to change were the ligand to bind to a metal centre. The steric influence of the bulky tert-butyl group is reflected in the C1-N1-C2 and C1-N1-C8 angles [113.90 (13) and 115.34 (13)°, respectively], being larger than the C2-N1-C8 angle of 110.08 (13)°. The methylene groups of the structure all adopt the expected staggered (lowest energy) conformation (Munro & Camp, 2003). The pyridyl ring containing atom N2 is orientated at 18 (1)° relative to the mean plane of the N-tert-butyl group (plane through C16-C1-N1), whilst that containing N3 is orientated at 74 (1)°.
There are no short van der Waals contacts less than the sum of the van der Waals radii in this system, reflected in the loose packing, however weak (possibly stabilizing) C-H···π intermolecular interactions do occur. The metrics of such interactions reflect a T-shaped, edge-to-face geometry. Specifically, let us define Cg1 as the centre of gravity of the pyridyl N2/C3-C7 ring and Cg2 the centre of gravity of the pyridyl N3/C9-C13 ring. A C-H···π interaction with a separation of 2.97 (1) Å exists between C7-H1 from the pyridyl ring containing atom N2 and Cg2 of neighbouring symmetry related molecule [symmetry code: (i) x -1/2, y -1/2, z] (Table 1). A similar C-H···π interaction with a separation of 2.94 (1) Å exists between C15-H16 from one of the methyl groups of the tert-butyl moiety and Cg1 on the symmetry related neighbouring molecule with symmetry code: (ii) x, -y, z -1/2. Figure 2 shows the packing within the unit cell for the title compound.

Experimental
The compound was synthesized following a literature method (Pal et al., 1992). Under a high flow of nitrogen, 6 ml of 20% NaOH solution was added to an aqueous solution of 2-picolyl chloridehydrochloride [(3.937 g (24 mmol) in 0.5 ml ultra pure water] to form a pink emulsion solution. 2-Amino-2-methyl propane (12 mmol) was added and the mixture stirred at 60°C. 40 ml of 20% NaOH solution was then added over a period of 1 h and the mixture left to stir for a further 12 h.
The crude product was extracted with CHCl 3 washed with ultra pure water and dried over Na 2 SO 4 . Excess solvent was removed under reduced pressure and the oil residue purified on a short chromatographic column packed with 0.5 g charcoal and 5 g of neutral alumina using CHCl 3 as an eluent to afford a light yellow solution. Colourless single crystals suitable for X-ray diffraction were obtained from slow evaporation of the solvent from its solution made from a 5% chloroform in ethanol solution (yield: 1.73 g, 60%).  H 8.29,N 16.46;Found: C 74.89,H 7.97,N 17.37.

Refinement
All Hydrogen atoms were positioned in geometrically idealized positions and constrained to ride on their parent atoms with C-H distances in the range 0.93-0.97 Å, and with U iso (H) = 1.2 or 1.5U eq (C). In the absence of significant anomalous scattering effects, Friedel pairs have been merged. Fig. 1. The molecular structure of the title compound, showing 50% probability displacement ellipsoids and atomic numbering. 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 Rfactors(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.  (11) 0.0110 (7) 0.0043 (9) 0.0033 (8)  C7 0.0539 (10) 0.0426 (9) 0.0702 (12) −0.0057 (7) 0.0127 (9) 0.0088 (8) Geometric parameters (Å, °)