supplementary materials


xu5637 scheme

Acta Cryst. (2012). E68, o3263    [ doi:10.1107/S1600536812044595 ]

(2,4,6-Trimethylphenyl){2-[N-(2,4,6-trimethylphenyl)formamido]ethyl}ammonium chloride

M. I. Ikhile and M. D. Bala

Abstract top

In the title salt, C21H29N2O+·Cl-, the benzene rings form a dihedral angle of 6.13 (1)°. In the crystal, N-H...Cl hydrogen bonds link the cations and anions into chains extending along the c axis.

Comment top

The title compound was isolated from the hydrolysis of an imidazolium based salt in a ring opening reaction. Stable N-heterocyclic carbene ligands are often prepared from imidazolium based salt precursors. However the reaction must be conducted under strict anaerobic conditions using Schlenk techniques, otherwise attack by moisture will lead to the isolation of products such as (I).

In (I) (Fig.1), the planes of the two phenyl rings (mean: C1–C6 and mean: C13–C18) form a dihedral angle of 6.13 (1)°. In the crystal, intermolecular N—H···Cl hydrogen bonds (Table 1) link the molecules into chains extending along the crystallographic c axis with a separation of 2.17–2.23 Å (Fig. 2).

Related literature top

For closely related compounds, see: Kocher & Hermann (1997); Denk et al. (2001).

Experimental top

A mixture of 1,3–bis(2,4,6-trimethyl phenyl)imidazolinium chloride (0.101 g, 0.29 mmol) and potassium tert-butoxide (0.039 g, 0.35 mmol) were dissolved in 20 ml of tetrahydrofuran and stirred at room temperature for 30 min. After evaporating the solvent, the free carbene was extracted in warm toluene (2 x 20 ml). FeCl2 (0.037 g, 0.29 mmol) was added to the toluene solution and refluxed for 24 h at 90 °C. Removal of the solvent gave a residue that was purified by recrystallization from CH2Cl2/hexane to yield orange crystals of (I). Yield: 0.05 g, 51%; m.p. 180 °C.

Refinement top

H-atoms were refined using a riding model, with C—H = 0.95 Å and Uiso(H) = 1.2Ueq(C) for aromatic and C—H = 0.98 Å and Uiso(H) = 1.5Ueq(C) for CH3. The amino H atoms were placed in calculated positions with N—H = 0.92 Å and refined in a riding mode with Uiso(H) = 1.2Ueq(N).

Computing details top

Data collection: APEX2 (Bruker, 2005); cell refinement: 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: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. ORTEP diagram of compound (I). Thermal ellipsoids are represented at the 50% probability level. Hydrogen atoms are eliminated for clarity.
[Figure 2] Fig. 2. Packing in the title compound showing the N—H···Cl hydrogen bonds.
(2,4,6-Trimethylphenyl){2-[N-(2,4,6- trimethylphenyl)formamido]ethyl}ammonium chloride top
Crystal data top
C21H29N2O+·ClZ = 2
Mr = 360.91F(000) = 388
Triclinic, P1Dx = 1.191 Mg m3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71073 Å
a = 8.2516 (2) ÅCell parameters from 3132 reflections
b = 8.8822 (2) Åθ = 2.5–24.0°
c = 14.7524 (4) ŵ = 0.20 mm1
α = 74.857 (2)°T = 173 K
β = 86.315 (2)°Block, colourless
γ = 74.635 (2)°0.36 × 0.21 × 0.11 mm
V = 1006.38 (5) Å3
Data collection top
Bruker APEXII CCD
diffractometer
2975 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.062
Graphite monochromatorθmax = 28.0°, θmin = 1.4°
φ and ω scansh = 1010
19610 measured reflectionsk = 1111
4853 independent reflectionsl = 1919
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.044Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.107H-atom parameters constrained
S = 0.90 w = 1/[σ2(Fo2) + (0.0478P)2]
where P = (Fo2 + 2Fc2)/3
4853 reflections(Δ/σ)max = 0.001
232 parametersΔρmax = 0.31 e Å3
0 restraintsΔρmin = 0.25 e Å3
Crystal data top
C21H29N2O+·Clγ = 74.635 (2)°
Mr = 360.91V = 1006.38 (5) Å3
Triclinic, P1Z = 2
a = 8.2516 (2) ÅMo Kα radiation
b = 8.8822 (2) ŵ = 0.20 mm1
c = 14.7524 (4) ÅT = 173 K
α = 74.857 (2)°0.36 × 0.21 × 0.11 mm
β = 86.315 (2)°
Data collection top
Bruker APEXII CCD
diffractometer
2975 reflections with I > 2σ(I)
19610 measured reflectionsRint = 0.062
4853 independent reflectionsθmax = 28.0°
Refinement top
R[F2 > 2σ(F2)] = 0.044H-atom parameters constrained
wR(F2) = 0.107Δρmax = 0.31 e Å3
S = 0.90Δρmin = 0.25 e Å3
4853 reflectionsAbsolute structure: ?
232 parametersFlack parameter: ?
0 restraintsRogers parameter: ?
Special details top

Experimental. IR (ATR cm-1): 2918, 2718, 2607, 1669, 1568, 1482, 1446, 1381, 1345, 1306, 1285, 1207, 1193, 1033, 850, 781, 705, 577, 477, 425; δH (400 MHz, CDCl3): 1.60 (6H, s, CH3), 2.16 (12H, m, CH3), 2.58 (3H, s, NH2), 3.76 (2H, s, NCH2NCHO), 6.83 (3H, s, ArH), 6.88 (2H, s, ArH) and 7.89 p.p.m. (1H, s, NCHO); δC (100 MHz, CDCl3): 18.09 (C6H2(CH3)3), 19.35 (C6H2(CH3)3), 21.15 (C6H2(CH3)3), 23.17 (C6H2(CH3)3), 51.12 (NHCH2), 52.08 (NCH2), 128.27, 130.18, 134.72, 135.91, 138.54, 140.21, 145.23 and 160.28 p.p.m. (NCHO); HRMS (ESI), Found, 325.22737 (M+ - Cl-) Calculated for C21H29N2O 325.22799 (M+ - Cl-).

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
C10.0762 (2)0.8248 (2)0.13320 (12)0.0263 (4)
C20.0175 (2)0.9590 (2)0.13117 (12)0.0298 (4)
C30.1346 (2)1.1060 (2)0.12548 (13)0.0347 (5)
H30.09581.19710.12660.042*
C40.3055 (2)1.1251 (2)0.11826 (13)0.0365 (5)
C50.3594 (2)0.9905 (2)0.11714 (13)0.0373 (5)
H50.47611.00210.11040.045*
C60.2486 (2)0.8385 (2)0.12561 (12)0.0318 (4)
C70.1675 (2)0.9497 (2)0.13254 (14)0.0390 (5)
H7A0.21070.90290.19690.058*
H7B0.18441.05840.10960.058*
H7C0.22770.88170.09200.058*
C80.4291 (3)1.2871 (3)0.11207 (17)0.0573 (6)
H8A0.40891.32960.16410.086*
H8B0.54391.27440.11590.086*
H8C0.41451.36220.05220.086*
C90.3162 (2)0.6959 (2)0.12768 (15)0.0441 (5)
H9A0.29340.66690.06760.066*
H9B0.43780.72390.13830.066*
H9C0.26160.60410.17860.066*
C100.0609 (2)0.5899 (2)0.07631 (14)0.0392 (5)
H100.00130.64350.01900.047*
C110.1348 (2)0.5881 (2)0.23205 (12)0.0288 (4)
H11A0.15080.66960.26300.035*
H11B0.24710.52340.21880.035*
C120.0402 (2)0.4789 (2)0.29708 (12)0.0277 (4)
H12A0.06800.54520.31430.033*
H12B0.01530.40420.26380.033*
C130.2789 (2)0.2444 (2)0.37526 (12)0.0249 (4)
C140.2386 (2)0.1044 (2)0.36930 (12)0.0265 (4)
C150.3711 (2)0.0292 (2)0.36709 (12)0.0320 (4)
H150.34670.12620.36340.038*
C160.5376 (2)0.0257 (2)0.37002 (12)0.0328 (4)
C170.5706 (2)0.1165 (2)0.37419 (13)0.0345 (5)
H170.68430.12050.37500.041*
C180.4440 (2)0.2546 (2)0.37721 (12)0.0280 (4)
C190.0599 (2)0.0917 (2)0.36649 (14)0.0345 (5)
H19A0.00980.15030.40900.052*
H19B0.05810.02210.38630.052*
H19C0.01550.13860.30240.052*
C200.6787 (2)0.1744 (2)0.36982 (15)0.0471 (6)
H20A0.63880.27120.39680.071*
H20B0.77300.17560.40740.071*
H20C0.71570.17270.30520.071*
C210.4916 (2)0.4051 (2)0.38237 (15)0.0409 (5)
H21A0.61290.37950.39340.061*
H21B0.43090.44570.43400.061*
H21C0.46200.48770.32310.061*
N10.04243 (17)0.66963 (18)0.14387 (10)0.0289 (3)
N20.13837 (16)0.38311 (16)0.38442 (10)0.0246 (3)
H2A0.18110.45180.40720.030*
H2B0.06520.34520.42870.030*
O10.14983 (17)0.45239 (18)0.08378 (10)0.0544 (4)
Cl10.13717 (5)0.66160 (5)0.47043 (3)0.03312 (14)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0249 (9)0.0308 (10)0.0200 (9)0.0033 (8)0.0015 (7)0.0046 (8)
C20.0297 (10)0.0356 (11)0.0228 (9)0.0091 (9)0.0013 (8)0.0041 (8)
C30.0427 (11)0.0315 (11)0.0277 (10)0.0080 (9)0.0031 (9)0.0043 (9)
C40.0357 (11)0.0368 (12)0.0290 (10)0.0015 (9)0.0019 (9)0.0052 (9)
C50.0236 (9)0.0494 (13)0.0331 (11)0.0026 (9)0.0023 (8)0.0069 (10)
C60.0280 (10)0.0399 (12)0.0261 (10)0.0075 (9)0.0019 (8)0.0065 (9)
C70.0321 (10)0.0436 (12)0.0413 (12)0.0132 (9)0.0015 (9)0.0071 (10)
C80.0571 (14)0.0446 (14)0.0557 (15)0.0123 (11)0.0079 (12)0.0117 (12)
C90.0331 (11)0.0495 (13)0.0516 (14)0.0140 (10)0.0051 (10)0.0115 (11)
C100.0345 (11)0.0473 (13)0.0331 (11)0.0000 (10)0.0053 (9)0.0152 (10)
C110.0262 (9)0.0323 (10)0.0252 (9)0.0033 (8)0.0053 (7)0.0056 (8)
C120.0225 (9)0.0274 (10)0.0295 (10)0.0014 (8)0.0067 (7)0.0044 (8)
C130.0222 (9)0.0263 (10)0.0226 (9)0.0004 (7)0.0028 (7)0.0058 (8)
C140.0265 (9)0.0268 (10)0.0232 (9)0.0025 (8)0.0016 (7)0.0052 (8)
C150.0372 (11)0.0276 (10)0.0275 (10)0.0028 (8)0.0009 (8)0.0067 (8)
C160.0313 (10)0.0345 (11)0.0242 (10)0.0044 (9)0.0000 (8)0.0060 (8)
C170.0208 (9)0.0479 (12)0.0291 (10)0.0014 (9)0.0001 (8)0.0077 (9)
C180.0232 (9)0.0363 (11)0.0234 (9)0.0056 (8)0.0026 (7)0.0074 (8)
C190.0322 (10)0.0308 (11)0.0443 (12)0.0095 (9)0.0002 (9)0.0143 (9)
C200.0418 (12)0.0468 (13)0.0361 (12)0.0127 (10)0.0024 (9)0.0070 (10)
C210.0272 (10)0.0490 (13)0.0514 (13)0.0133 (9)0.0024 (9)0.0172 (11)
N10.0295 (8)0.0312 (9)0.0227 (8)0.0015 (7)0.0042 (6)0.0065 (7)
N20.0225 (7)0.0259 (8)0.0264 (8)0.0065 (6)0.0002 (6)0.0079 (6)
O10.0514 (9)0.0540 (10)0.0525 (10)0.0147 (8)0.0150 (8)0.0295 (8)
Cl10.0312 (3)0.0314 (3)0.0414 (3)0.0118 (2)0.0066 (2)0.0148 (2)
Geometric parameters (Å, º) top
C1—C21.394 (2)C11—H11B0.9900
C1—C61.404 (2)C12—N21.495 (2)
C1—N11.440 (2)C12—H12A0.9900
C2—C31.389 (2)C12—H12B0.9900
C2—C71.508 (2)C13—C181.392 (2)
C3—C41.383 (3)C13—C141.394 (2)
C3—H30.9500C13—N21.4802 (19)
C4—C51.385 (3)C14—C151.391 (2)
C4—C81.511 (3)C14—C191.513 (2)
C5—C61.396 (2)C15—C161.386 (2)
C5—H50.9500C15—H150.9500
C6—C91.506 (3)C16—C171.378 (3)
C7—H7A0.9800C16—C201.512 (2)
C7—H7B0.9800C17—C181.393 (2)
C7—H7C0.9800C17—H170.9500
C8—H8A0.9800C18—C211.511 (2)
C8—H8B0.9800C19—H19A0.9800
C8—H8C0.9800C19—H19B0.9800
C9—H9A0.9800C19—H19C0.9800
C9—H9B0.9800C20—H20A0.9800
C9—H9C0.9800C20—H20B0.9800
C10—O11.227 (2)C20—H20C0.9800
C10—N11.345 (2)C21—H21A0.9800
C10—H100.9500C21—H21B0.9800
C11—N11.463 (2)C21—H21C0.9800
C11—C121.513 (2)N2—H2A0.9200
C11—H11A0.9900N2—H2B0.9200
C2—C1—C6121.13 (16)N2—C12—H12B109.2
C2—C1—N1119.19 (15)C11—C12—H12B109.2
C6—C1—N1119.69 (15)H12A—C12—H12B107.9
C3—C2—C1118.23 (16)C18—C13—C14122.59 (15)
C3—C2—C7119.68 (16)C18—C13—N2119.86 (15)
C1—C2—C7122.08 (16)C14—C13—N2117.49 (14)
C4—C3—C2122.63 (18)C15—C14—C13117.36 (15)
C4—C3—H3118.7C15—C14—C19119.38 (16)
C2—C3—H3118.7C13—C14—C19123.25 (15)
C3—C4—C5117.69 (17)C16—C15—C14122.21 (17)
C3—C4—C8121.08 (19)C16—C15—H15118.9
C5—C4—C8121.24 (18)C14—C15—H15118.9
C4—C5—C6122.44 (17)C17—C16—C15118.06 (16)
C4—C5—H5118.8C17—C16—C20121.05 (17)
C6—C5—H5118.8C15—C16—C20120.88 (18)
C5—C6—C1117.82 (17)C16—C17—C18122.75 (17)
C5—C6—C9119.69 (16)C16—C17—H17118.6
C1—C6—C9122.49 (17)C18—C17—H17118.6
C2—C7—H7A109.5C13—C18—C17117.00 (16)
C2—C7—H7B109.5C13—C18—C21123.79 (16)
H7A—C7—H7B109.5C17—C18—C21119.21 (16)
C2—C7—H7C109.5C14—C19—H19A109.5
H7A—C7—H7C109.5C14—C19—H19B109.5
H7B—C7—H7C109.5H19A—C19—H19B109.5
C4—C8—H8A109.5C14—C19—H19C109.5
C4—C8—H8B109.5H19A—C19—H19C109.5
H8A—C8—H8B109.5H19B—C19—H19C109.5
C4—C8—H8C109.5C16—C20—H20A109.5
H8A—C8—H8C109.5C16—C20—H20B109.5
H8B—C8—H8C109.5H20A—C20—H20B109.5
C6—C9—H9A109.5C16—C20—H20C109.5
C6—C9—H9B109.5H20A—C20—H20C109.5
H9A—C9—H9B109.5H20B—C20—H20C109.5
C6—C9—H9C109.5C18—C21—H21A109.5
H9A—C9—H9C109.5C18—C21—H21B109.5
H9B—C9—H9C109.5H21A—C21—H21B109.5
O1—C10—N1124.35 (18)C18—C21—H21C109.5
O1—C10—H10117.8H21A—C21—H21C109.5
N1—C10—H10117.8H21B—C21—H21C109.5
N1—C11—C12110.66 (14)C10—N1—C1121.01 (15)
N1—C11—H11A109.5C10—N1—C11118.12 (15)
C12—C11—H11A109.5C1—N1—C11120.64 (14)
N1—C11—H11B109.5C13—N2—C12116.63 (13)
C12—C11—H11B109.5C13—N2—H2A108.1
H11A—C11—H11B108.1C12—N2—H2A108.1
N2—C12—C11111.89 (13)C13—N2—H2B108.1
N2—C12—H12A109.2C12—N2—H2B108.1
C11—C12—H12A109.2H2A—N2—H2B107.3
C6—C1—C2—C32.7 (3)C19—C14—C15—C16179.61 (17)
N1—C1—C2—C3176.89 (16)C14—C15—C16—C170.8 (3)
C6—C1—C2—C7175.73 (17)C14—C15—C16—C20178.54 (17)
N1—C1—C2—C74.6 (3)C15—C16—C17—C181.2 (3)
C1—C2—C3—C42.5 (3)C20—C16—C17—C18178.12 (17)
C7—C2—C3—C4176.02 (17)C14—C13—C18—C170.8 (3)
C2—C3—C4—C50.3 (3)N2—C13—C18—C17176.08 (15)
C2—C3—C4—C8179.90 (18)C14—C13—C18—C21179.17 (17)
C3—C4—C5—C61.8 (3)N2—C13—C18—C213.9 (3)
C8—C4—C5—C6178.02 (19)C16—C17—C18—C130.4 (3)
C4—C5—C6—C11.6 (3)C16—C17—C18—C21179.60 (17)
C4—C5—C6—C9177.59 (18)O1—C10—N1—C1174.15 (17)
C2—C1—C6—C50.8 (3)O1—C10—N1—C110.4 (3)
N1—C1—C6—C5178.83 (15)C2—C1—N1—C10117.52 (19)
C2—C1—C6—C9179.92 (17)C6—C1—N1—C1062.9 (2)
N1—C1—C6—C90.3 (3)C2—C1—N1—C1168.1 (2)
N1—C11—C12—N2175.09 (13)C6—C1—N1—C11111.52 (18)
C18—C13—C14—C151.2 (3)C12—C11—N1—C1083.4 (2)
N2—C13—C14—C15175.77 (15)C12—C11—N1—C191.09 (18)
C18—C13—C14—C19179.60 (17)C18—C13—N2—C12106.18 (18)
N2—C13—C14—C193.4 (2)C14—C13—N2—C1276.74 (19)
C13—C14—C15—C160.4 (3)C11—C12—N2—C1375.89 (18)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N2—H2A···Cl10.922.233.0585 (14)149
N2—H2B···Cl1i0.922.173.0531 (14)161
Symmetry code: (i) x, y+1, z+1.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N2—H2A···Cl10.922.233.0585 (14)149.2
N2—H2B···Cl1i0.922.173.0531 (14)161.4
Symmetry code: (i) x, y+1, z+1.
Acknowledgements top

We thank Dr Manuel Fernandes for the data collection and the University of KwaZulu-Natal for financial support.

references
References top

Bruker (2005). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.

Denk, M. K., Rodezno, J. M., Gupta, S. & Lough, A. J. (2001). J. Organomet. Chem. 617, 242–253.

Kocher, C. & Hermann, W. A. (1997). J. Organomet. Chem. 532, 261–265.

Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.