organic compounds
6-Chloro-2,4-bis(dimethylamino)-1,3,5-trimethylborazine
aPO Box 5800, MS 1411, Sandia National Laboratories, Albuquerque, NM 87185-1411, USA, and bPO Box 5800, MS 0892, Sandia National Laboratories, Albuquerque, NM 87185-0892, USA
*Correspondence e-mail: marodri@sandia.gov
The borazine ring of the title molecule, C7H21B3ClN5, shows a mild distortion from a planar to a flattened boat conformation. Steric effects due to the methyl and dimethylamine substituents appear to be the cause of this distortion.
Related literature
The borazine ring in 2,4,6-tris(dimethylamino)-1,3,5-trimethylborazine (Rodriguez & Borek, 2006) shows a greater distortion from planarity towards a boat conformation compared to the title compound. For the synthesis, see: Beachley & Durkin (1974).
Experimental
Crystal data
|
Data collection: APEX2 (Bruker, 2005); cell SAINT (Bruker, 2005); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL; molecular graphics: XSHELL (Bruker, 2000); software used to prepare material for publication: SHELXTL.
Supporting information
10.1107/S1600536813002420/lh5576sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536813002420/lh5576Isup2.hkl
Supporting information file. DOI: 10.1107/S1600536813002420/lh5576Isup3.cml
Compound (1) was obtained using a modification of the published procedure of Beachley and Durkin (1974). One equivalent of 2,4,6-trichloro-1,3,5-trimethylborazine was reacted with 4 equivalents of anhydrous dimethylamine in anhydrous diethyl ether at room temperature. After stirring the reaction mixture overnight, the solution was filtered to remove precipitated dimethylammonium hydrochloride, and the solvent was removed using vacuum techniques. This product was then recrystallized from anhydrous hexanes, and then vacuum distilled (bp 355K at 270 mTorr). The liquid distillate slowly crystallized upon standing at room temperature resulting in a low melting point white solid with individual crystals displaying sufficient quality and size for single
analysis. The product purity was determined by nuclear magnetic resonance (1H, 11B, 13 C) and by gas chromatography/mass spectrometry.H atoms were placed in calculated positions with C—H = 0.98Å and included in the
in a riding-motion approximation with Uiso(H) = 1.5Ueq(C).Data collection: APEX2 (Bruker, 2005); cell
SAINT (Bruker, 2005); data reduction: SAINT (Bruker, 2005); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: XSHELL (Bruker, 2000); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).C7H21B3ClN5 | F(000) = 520 |
Mr = 243.17 | Dx = 1.216 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 200 reflections |
a = 8.493 (3) Å | θ = 2.4–28.0° |
b = 10.285 (3) Å | µ = 0.27 mm−1 |
c = 15.247 (5) Å | T = 193 K |
β = 94.512 (4)° | Irregular, colorless |
V = 1327.8 (7) Å3 | 0.25 × 0.20 × 0.15 mm |
Z = 4 |
Bruker APEXII CCD diffractometer | 2397 independent reflections |
Radiation source: fine-focus sealed tube | 1757 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.037 |
ω and ϕ scans | θmax = 25.3°, θmin = 2.4° |
Absorption correction: multi-scan (SADABS; Bruker, 2005) | h = −10→10 |
Tmin = 0.935, Tmax = 0.962 | k = −12→12 |
9381 measured reflections | l = −17→18 |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.040 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.110 | H-atom parameters constrained |
S = 1.03 | w = 1/[σ2(Fo2) + (0.0507P)2 + 0.4074P] where P = (Fo2 + 2Fc2)/3 |
2397 reflections | (Δ/σ)max = 0.001 |
152 parameters | Δρmax = 0.18 e Å−3 |
0 restraints | Δρmin = −0.23 e Å−3 |
C7H21B3ClN5 | V = 1327.8 (7) Å3 |
Mr = 243.17 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 8.493 (3) Å | µ = 0.27 mm−1 |
b = 10.285 (3) Å | T = 193 K |
c = 15.247 (5) Å | 0.25 × 0.20 × 0.15 mm |
β = 94.512 (4)° |
Bruker APEXII CCD diffractometer | 2397 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2005) | 1757 reflections with I > 2σ(I) |
Tmin = 0.935, Tmax = 0.962 | Rint = 0.037 |
9381 measured reflections |
R[F2 > 2σ(F2)] = 0.040 | 0 restraints |
wR(F2) = 0.110 | H-atom parameters constrained |
S = 1.03 | Δρmax = 0.18 e Å−3 |
2397 reflections | Δρmin = −0.23 e Å−3 |
152 parameters |
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 F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. |
x | y | z | Uiso*/Ueq | ||
B1 | 0.6753 (3) | 0.9822 (2) | −0.09252 (15) | 0.0322 (5) | |
B2 | 0.7277 (3) | 0.7848 (2) | −0.00232 (15) | 0.0298 (5) | |
B3 | 0.7837 (3) | 1.0095 (2) | 0.06221 (15) | 0.0302 (5) | |
Cl1 | 0.61969 (8) | 1.05390 (6) | −0.19852 (4) | 0.0508 (2) | |
N1 | 0.66654 (19) | 0.84528 (15) | −0.08386 (10) | 0.0309 (4) | |
N2 | 0.72169 (19) | 1.06502 (15) | −0.02140 (10) | 0.0308 (4) | |
N3 | 0.79205 (19) | 0.86955 (15) | 0.06702 (10) | 0.0311 (4) | |
N4 | 0.7296 (2) | 0.64530 (16) | 0.00767 (12) | 0.0386 (4) | |
N5 | 0.8378 (2) | 1.09064 (17) | 0.13484 (11) | 0.0380 (4) | |
C1 | 0.5793 (3) | 0.7691 (2) | −0.15374 (14) | 0.0406 (5) | |
H1A | 0.4897 | 0.8202 | −0.1793 | 0.061* | |
H1B | 0.5406 | 0.6885 | −0.1288 | 0.061* | |
H1C | 0.6498 | 0.7481 | −0.1997 | 0.061* | |
C2 | 0.6864 (3) | 1.20525 (19) | −0.02956 (15) | 0.0412 (5) | |
H2A | 0.7721 | 1.2491 | −0.0573 | 0.062* | |
H2B | 0.6767 | 1.2422 | 0.0290 | 0.062* | |
H2C | 0.5871 | 1.2175 | −0.0658 | 0.062* | |
C3 | 0.9084 (3) | 0.8124 (2) | 0.13352 (14) | 0.0427 (6) | |
H3A | 0.9930 | 0.8753 | 0.1483 | 0.064* | |
H3B | 0.9532 | 0.7333 | 0.1097 | 0.064* | |
H3C | 0.8559 | 0.7907 | 0.1866 | 0.064* | |
C4 | 0.7744 (3) | 0.5554 (2) | −0.05884 (17) | 0.0481 (6) | |
H4A | 0.8084 | 0.6041 | −0.1093 | 0.072* | |
H4B | 0.6837 | 0.5005 | −0.0780 | 0.072* | |
H4C | 0.8614 | 0.5005 | −0.0344 | 0.072* | |
C5 | 0.6986 (3) | 0.5823 (2) | 0.08946 (17) | 0.0541 (7) | |
H5A | 0.7963 | 0.5433 | 0.1160 | 0.081* | |
H5B | 0.6189 | 0.5143 | 0.0778 | 0.081* | |
H5C | 0.6596 | 0.6466 | 0.1299 | 0.081* | |
C6 | 0.8211 (3) | 1.0560 (2) | 0.22612 (14) | 0.0490 (6) | |
H6A | 0.7483 | 0.9824 | 0.2285 | 0.074* | |
H6B | 0.7791 | 1.1305 | 0.2569 | 0.074* | |
H6C | 0.9244 | 1.0319 | 0.2545 | 0.074* | |
C7 | 0.9317 (3) | 1.2072 (2) | 0.12748 (16) | 0.0509 (6) | |
H7A | 0.9510 | 1.2215 | 0.0657 | 0.076* | |
H7B | 1.0328 | 1.1970 | 0.1624 | 0.076* | |
H7C | 0.8748 | 1.2819 | 0.1493 | 0.076* |
U11 | U22 | U33 | U12 | U13 | U23 | |
B1 | 0.0316 (13) | 0.0337 (13) | 0.0314 (12) | 0.0012 (10) | 0.0023 (10) | 0.0042 (10) |
B2 | 0.0303 (12) | 0.0281 (12) | 0.0314 (12) | −0.0014 (10) | 0.0052 (9) | 0.0012 (10) |
B3 | 0.0298 (13) | 0.0308 (12) | 0.0304 (12) | −0.0014 (10) | 0.0044 (10) | −0.0002 (10) |
Cl1 | 0.0710 (4) | 0.0453 (3) | 0.0342 (3) | 0.0001 (3) | −0.0081 (3) | 0.0116 (3) |
N1 | 0.0351 (10) | 0.0279 (9) | 0.0291 (9) | −0.0012 (7) | −0.0014 (7) | −0.0008 (7) |
N2 | 0.0379 (10) | 0.0227 (8) | 0.0320 (9) | 0.0005 (7) | 0.0032 (7) | 0.0012 (7) |
N3 | 0.0348 (10) | 0.0303 (9) | 0.0273 (9) | 0.0019 (7) | −0.0022 (7) | 0.0037 (7) |
N4 | 0.0491 (11) | 0.0273 (9) | 0.0396 (10) | −0.0002 (8) | 0.0046 (8) | 0.0046 (8) |
N5 | 0.0463 (11) | 0.0351 (10) | 0.0328 (9) | −0.0062 (8) | 0.0037 (8) | −0.0048 (8) |
C1 | 0.0465 (13) | 0.0369 (12) | 0.0372 (12) | −0.0044 (10) | −0.0047 (10) | −0.0056 (10) |
C2 | 0.0523 (14) | 0.0250 (11) | 0.0468 (13) | 0.0051 (10) | 0.0079 (11) | 0.0027 (10) |
C3 | 0.0453 (13) | 0.0443 (13) | 0.0370 (12) | 0.0047 (11) | −0.0070 (10) | 0.0059 (10) |
C4 | 0.0518 (15) | 0.0294 (12) | 0.0631 (16) | 0.0010 (11) | 0.0034 (12) | −0.0060 (11) |
C5 | 0.0604 (17) | 0.0430 (14) | 0.0589 (16) | −0.0044 (12) | 0.0037 (13) | 0.0200 (12) |
C6 | 0.0556 (15) | 0.0590 (15) | 0.0318 (12) | −0.0033 (12) | −0.0009 (10) | −0.0053 (11) |
C7 | 0.0521 (15) | 0.0469 (14) | 0.0536 (15) | −0.0107 (12) | 0.0028 (12) | −0.0141 (12) |
B1—N2 | 1.410 (3) | C2—H2A | 0.9800 |
B1—N1 | 1.417 (3) | C2—H2B | 0.9800 |
B1—Cl1 | 1.805 (2) | C2—H2C | 0.9800 |
B2—N4 | 1.443 (3) | C3—H3A | 0.9800 |
B2—N3 | 1.444 (3) | C3—H3B | 0.9800 |
B2—N1 | 1.450 (3) | C3—H3C | 0.9800 |
B3—N5 | 1.433 (3) | C4—H4A | 0.9800 |
B3—N3 | 1.443 (3) | C4—H4B | 0.9800 |
B3—N2 | 1.457 (3) | C4—H4C | 0.9800 |
N1—C1 | 1.474 (2) | C5—H5A | 0.9800 |
N2—C2 | 1.476 (2) | C5—H5B | 0.9800 |
N3—C3 | 1.481 (3) | C5—H5C | 0.9800 |
N4—C4 | 1.446 (3) | C6—H6A | 0.9800 |
N4—C5 | 1.448 (3) | C6—H6B | 0.9800 |
N5—C7 | 1.449 (3) | C6—H6C | 0.9800 |
N5—C6 | 1.454 (3) | C7—H7A | 0.9800 |
C1—H1A | 0.9800 | C7—H7B | 0.9800 |
C1—H1B | 0.9800 | C7—H7C | 0.9800 |
C1—H1C | 0.9800 | ||
N2—B1—N1 | 122.81 (19) | N2—C2—H2C | 109.5 |
N2—B1—Cl1 | 118.66 (16) | H2A—C2—H2C | 109.5 |
N1—B1—Cl1 | 118.51 (16) | H2B—C2—H2C | 109.5 |
N4—B2—N3 | 121.51 (19) | N3—C3—H3A | 109.5 |
N4—B2—N1 | 121.18 (19) | N3—C3—H3B | 109.5 |
N3—B2—N1 | 117.26 (18) | H3A—C3—H3B | 109.5 |
N5—B3—N3 | 122.03 (19) | N3—C3—H3C | 109.5 |
N5—B3—N2 | 121.31 (19) | H3A—C3—H3C | 109.5 |
N3—B3—N2 | 116.64 (18) | H3B—C3—H3C | 109.5 |
B1—N1—B2 | 119.26 (17) | N4—C4—H4A | 109.5 |
B1—N1—C1 | 119.19 (17) | N4—C4—H4B | 109.5 |
B2—N1—C1 | 121.17 (16) | H4A—C4—H4B | 109.5 |
B1—N2—B3 | 119.74 (17) | N4—C4—H4C | 109.5 |
B1—N2—C2 | 118.85 (17) | H4A—C4—H4C | 109.5 |
B3—N2—C2 | 120.90 (17) | H4B—C4—H4C | 109.5 |
B3—N3—B2 | 123.44 (17) | N4—C5—H5A | 109.5 |
B3—N3—C3 | 117.28 (17) | N4—C5—H5B | 109.5 |
B2—N3—C3 | 117.08 (17) | H5A—C5—H5B | 109.5 |
B2—N4—C4 | 124.30 (18) | N4—C5—H5C | 109.5 |
B2—N4—C5 | 122.33 (18) | H5A—C5—H5C | 109.5 |
C4—N4—C5 | 113.18 (18) | H5B—C5—H5C | 109.5 |
B3—N5—C7 | 124.53 (18) | N5—C6—H6A | 109.5 |
B3—N5—C6 | 123.20 (18) | N5—C6—H6B | 109.5 |
C7—N5—C6 | 111.87 (18) | H6A—C6—H6B | 109.5 |
N1—C1—H1A | 109.5 | N5—C6—H6C | 109.5 |
N1—C1—H1B | 109.5 | H6A—C6—H6C | 109.5 |
H1A—C1—H1B | 109.5 | H6B—C6—H6C | 109.5 |
N1—C1—H1C | 109.5 | N5—C7—H7A | 109.5 |
H1A—C1—H1C | 109.5 | N5—C7—H7B | 109.5 |
H1B—C1—H1C | 109.5 | H7A—C7—H7B | 109.5 |
N2—C2—H2A | 109.5 | N5—C7—H7C | 109.5 |
N2—C2—H2B | 109.5 | H7A—C7—H7C | 109.5 |
H2A—C2—H2B | 109.5 | H7B—C7—H7C | 109.5 |
Experimental details
Crystal data | |
Chemical formula | C7H21B3ClN5 |
Mr | 243.17 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 193 |
a, b, c (Å) | 8.493 (3), 10.285 (3), 15.247 (5) |
β (°) | 94.512 (4) |
V (Å3) | 1327.8 (7) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.27 |
Crystal size (mm) | 0.25 × 0.20 × 0.15 |
Data collection | |
Diffractometer | Bruker APEXII CCD diffractometer |
Absorption correction | Multi-scan (SADABS; Bruker, 2005) |
Tmin, Tmax | 0.935, 0.962 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 9381, 2397, 1757 |
Rint | 0.037 |
(sin θ/λ)max (Å−1) | 0.601 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.040, 0.110, 1.03 |
No. of reflections | 2397 |
No. of parameters | 152 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.18, −0.23 |
Computer programs: APEX2 (Bruker, 2005), SAINT (Bruker, 2005), SHELXTL (Sheldrick, 2008), XSHELL (Bruker, 2000).
Acknowledgements
Sandia is a multiprogram laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the United States Department of Energy's National Nuclear Security Administration under contract DE–AC04-94 A L85000.
References
Beachley, O. T. Jr & Durkin, T. R. (1974). Inorg. Chem. 13, 1768–1770. CrossRef CAS Web of Science Google Scholar
Bruker (2000). XSHELL. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Bruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Rodriguez, M. A. & Borek, T. T. (2006). Acta Cryst. E62, o3341–o3343. Web of Science CSD CrossRef IUCr Journals Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.
2,4-Bis(dimethylamino)-6-chloro-1,3,5-trimethylborazine (I) is a low melting point solid white material that has not been previously reported. Fig. 1 shows this molecule as an atomic displacement ellipsoid plot. All bond lengths for the dimethylamine (DMA) ligands, B—N bonds, and B—Cl bond are consistent with expected values. The heterogeneous nature of the ligands bound to the Boron atoms (one Cl and two DMA molecules) along with the steric nature of the DMA ligands with proximity to methyl groups bound to the nitrogen atoms of the borazine ring creates conditions in the molecule that drive the borazine ring away from a purely planar configuration. By defining the planar portion of the ring via the atoms N1/N2/B2/B3 and comparing the rotation of the DMA ligands away from the plane of the ring, dihedral angles may be obtained. For the case of the DMA ligand labeled with the N4 nitrogen (B2/N4/C4/C5 plane) the dihedral angle is 39.20 (7)° rotated out of borazine plane; the DMA ligand labeled with the N5 nitrogen (B3/N5/C6/C7 plane) has a dihedral angle of 37.25 (7)°, however it is rotated in the opposite direction. Fig. 2 shows an edge-on view of the molecule which better illustrates the dihedral rotation of the DMA molecules. Fig. 2 also serves to illustrate that the counter-rotations of the DMA molecules results in the C5 and C6 methyl groups being closer in proximity to the DMA-bracketed C3 methyl when compared to their respective DMA methyl counterparts residing above (in terms of the molecule orientation in the figure) the borazine plane (i.e. C4 and C7). The proximity of C5 and C6 methyl groups to C3 forces the C3 methyl to deviate, out of the plane of the borazine ring (N1/N2/B3/B2) by 16.5 (1)° (B2/B3/N3/C3). Figure 2 also illustrates that the Cl1 atom shifts slightly out of the borazine plane. This angular devation of the Cl1 atom is 6.38 (8)° (N2/B1/N1/Cl1) and the net result is a boat-type borazine configuration. The reduced severity of the Cl1 deviation from planar is likely due to the absence of bracketing DMA molecules. Instead, Cl1 is bracketed by methyl groups C1 and C2.
Figure 3 and 4 shows the packing arrangement in (I). Figure 3 illustrates the layering of the four molecules of (I) within the unit cell. Based on the long interaction distances between the terminal chlorine and the methyl hydrogen atoms of neighboring molecules, there does not appear to be significant hydrogren bonding interactions within this structure, and packing appears to be dictated by Van der Waals interactions. Figure 4 serves to illustrate the symmetry operators of the 21 screw-axis and c-glide plane to replicate the molecule spatially along the b axis direction of the unit cell. In this figure, several molecules were removed for clarity.