Crystal structure of borated N,N,N′,N′-tetramethyldiaminomethane

In the title compound, {[(dimethylamino)methyl]dimethylamine}trihydridoboron, C5H17BN2, the tetrahedral geometry of the N—C—N unit is slightly disorted. As a result of the bulky amine substituents, a wider N—C—N angle of 113.6 (1)° is observed. The bond lengths between the N atom and methyl groups are slighly elongated to 1.481 (2) and 1.482 (2) Å at the borated N atom, whereas the distances between the other N atom and its methyl groups are only 1.461 (2) and 1.462 (2) Å. The studied crystal was twinned. The twin data refinement was subsequently carried out with a scale factor of 0.263 (1). The two lattices of the twin domains were rotated by 179.84°.

The title compound crystallizes in the triclinic crystal system with space group P-1. A torsion angle of 179.82 (13)° can be observed for B1-N1-C3-N2, placing B1 as far away from C3 and its hydrogen atoms as possible.

S1.2. Refinement
Crystal data, data collection and structure refinement details are summarized in Table 1. Hydrogen atoms linked to carbon were placed and refined by using the riding model (C-H = 0.95-0.99 Å, U iso (H) = 1.2 U eq (C) and U iso (H) = 1.5 U eq (C) for terminal groups). Hydrogen atoms linked to boron were taken from difference Fourier maps.
Twin domains were found in the crystal and refined to a ratio of 0.26/0.74. The two lattices were rotated by 179.84°.
HKLF5 refletion file was used for refinement.

Figure 1
Molecular structure of the title compound with displacement ellipsoids drawn at 50% probability level.