trans,trans-2,3,4-Triphenyl­azetidinium bromide

In the crystal structure of the title compound, C₂₁H₂₀N⁺·Br^-, two azetidinium cations act as hydrogen-bond donors and two bromide anions as acceptors, forming hydrogen-bonded dimers. The hydrogen-bond motif is that of the well known R₂⁴(6) ring. The degree of folding of the central azetidine ring is indicated by the torsion angles, one of which is 19.5 (3)°.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.006 Å
• R factor = 0.042
• wR factor = 0.097
• Data-to-parameter ratio = 13.4

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT125_ALERT_4_C No _symmetry_space_group_name_Hall Given .......          ?
PLAT164_ALERT_4_C Nr. of Refined C-H H-Atoms in Heavy-At Struct...          3
PLAT199_ALERT_1_C Check the Reported _cell_measurement_temperature        293 K
PLAT200_ALERT_1_C Check the Reported _diffrn_ambient_temperature .        293 K
PLAT222_ALERT_3_C Large Non-Solvent    H     Ueq(max)/Ueq(min) ...       3.42 Ratio
PLAT480_ALERT_4_C Long H...A H-Bond Reported H11    ..  BR      ..       2.99 Ang.
PLAT790_ALERT_4_C Centre of Gravity not Within Unit Cell: Resd.  #          2
              Br

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   7 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 ALERT type 3 Indicator that the structure quality may be low
   4 ALERT type 4 Improvement, methodology, query or suggestion

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Computing details

Data collection: CrysAlis CCD (Kuma Diffraction, 2000); cell refinement: CrysAlis RED (Kuma Diffraction, 2000); data reduction: CrysAlis RED; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: DIAMOND (Brandenburg, 2001); software used to prepare material for publication: SHELXL97.

trans,trans-2,3,4-Triphenylazetidinium bromide

Crystal data

C21H20N^+·Br^−	Z = 2
Mr = 366.29	F(000) = 376
Triclinic, P1	Dx = 1.388 Mg m^−3
a = 6.0658 (6) Å	Mo Kα radiation, λ = 0.71073 Å
b = 10.9797 (11) Å	Cell parameters from 4600 reflections
c = 13.8090 (13) Å	θ = 7.2–20.3°
α = 107.500 (9)°	µ = 2.35 mm^−1
β = 90.460 (8)°	T = 293 K
γ = 92.119 (8)°	Needle, colourless
V = 876.35 (15) Å^3	0.30 × 0.15 × 0.15 mm

Data collection

Stoe Stadi CCD diffractometer	2719 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.060
Graphite monochromator	θmax = 25.0°, θmin = 3.1°
ω scans	h = −7→7
9652 measured reflections	k = −13→13
3062 independent reflections	l = −16→16

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.042	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.097	w = 1/[σ^2(Fo^2) + (0.02P)^2 + 2P] where P = (Fo^2 + 2Fc^2)/3
S = 1.02	(Δ/σ)max = 0.005
3062 reflections	Δρmax = 0.75 e Å^−3
229 parameters	Δρmin = −1.02 e Å^−3
0 restraints	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0058 (15)

Special details

Experimental. Diffraction: A single-crystal of the title compound was mounted on a Stoe four-circle diffractometer equipped with a CCD-detector (Stadi-CCD). For the data collection 21 omega-scans (1.0 °) with different chi, phi and 2theta settings and a detector to crystal distance of 80 mm were performed. Integration procedures using variable and intensity dependant integration masks and integration width of 1.00 ° yielded a data completeness of more than 99.0% up to a Bragg angle of 50° two-theta.

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 (Ų)

	x	y	z	Uiso*/Ueq
Br	−0.28219 (6)	0.65394 (3)	0.52466 (3)	0.04180 (16)
N1	0.1899 (6)	0.6306 (3)	0.6394 (2)	0.0332 (6)
H12	0.066 (7)	0.637 (4)	0.618 (3)	0.041 (11)*
H11	0.269 (7)	0.593 (4)	0.591 (3)	0.053 (12)*
C2	0.1958 (6)	0.5828 (3)	0.7314 (2)	0.0345 (7)
H2	0.319 (6)	0.541 (3)	0.727 (2)	0.024 (8)*
C3	0.2103 (6)	0.7240 (3)	0.7994 (2)	0.0322 (7)
H3	0.065 (6)	0.750 (3)	0.813 (2)	0.031 (9)*
C4	0.2881 (5)	0.7601 (3)	0.7056 (2)	0.0311 (7)
H4	0.440 (6)	0.751 (3)	0.700 (2)	0.029 (8)*
C21	0.0129 (6)	0.4957 (3)	0.7464 (2)	0.0350 (7)
C22	0.0112 (8)	0.4660 (4)	0.8374 (3)	0.0575 (11)
H22	0.1248	0.4978	0.8850	0.069*
C23	−0.1563 (9)	0.3903 (5)	0.8578 (3)	0.0684 (13)
H23	−0.1555	0.3715	0.9191	0.082*
C24	−0.3254 (8)	0.3422 (4)	0.7881 (3)	0.0563 (11)
H24	−0.4403	0.2925	0.8027	0.068*
C25	−0.3229 (7)	0.3683 (3)	0.6970 (3)	0.0476 (9)
H25	−0.4352	0.3346	0.6491	0.057*
C26	−0.1543 (6)	0.4444 (3)	0.6759 (3)	0.0399 (8)
H26	−0.1537	0.4611	0.6137	0.048*
C31	0.3510 (6)	0.7636 (3)	0.8945 (2)	0.0364 (8)
C36	0.2805 (7)	0.8556 (4)	0.9802 (3)	0.0478 (9)
H36	0.1435	0.8906	0.9793	0.057*
C35	0.4137 (9)	0.8958 (4)	1.0675 (3)	0.0640 (13)
H35	0.3660	0.9587	1.1240	0.077*
C34	0.6134 (9)	0.8440 (5)	1.0709 (3)	0.0665 (14)
H34	0.7007	0.8709	1.1298	0.080*
C33	0.6844 (8)	0.7523 (5)	0.9876 (4)	0.0665 (13)
H33	0.8202	0.7166	0.9899	0.080*
C32	0.5544 (7)	0.7122 (4)	0.8991 (3)	0.0555 (11)
H32	0.6048	0.6502	0.8426	0.067*
C41	0.2198 (5)	0.8781 (3)	0.6822 (2)	0.0337 (7)
C42	0.0155 (6)	0.9303 (4)	0.7097 (3)	0.0491 (9)
H42	−0.0849	0.8905	0.7422	0.059*
C43	−0.0382 (8)	1.0413 (4)	0.6886 (4)	0.0601 (11)
H43	−0.1745	1.0759	0.7080	0.072*
C44	0.1036 (8)	1.1006 (4)	0.6403 (4)	0.0599 (11)
H44	0.0647	1.1744	0.6256	0.072*
C45	0.3073 (9)	1.0494 (4)	0.6133 (4)	0.0644 (12)
H45	0.4071	1.0900	0.5811	0.077*
C46	0.3634 (7)	0.9394 (4)	0.6333 (3)	0.0501 (10)
H46	0.5001	0.9056	0.6137	0.060*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br	0.0411 (2)	0.0397 (2)	0.0401 (2)	0.00716 (15)	−0.00260 (15)	0.00470 (15)
N1	0.0336 (17)	0.0336 (15)	0.0277 (14)	0.0064 (13)	0.0008 (13)	0.0015 (11)
C2	0.0351 (19)	0.0311 (17)	0.0327 (17)	0.0064 (15)	−0.0045 (14)	0.0020 (13)
C3	0.0282 (18)	0.0313 (17)	0.0328 (16)	0.0013 (14)	0.0006 (14)	0.0031 (13)
C4	0.0233 (17)	0.0333 (17)	0.0312 (16)	0.0010 (13)	0.0002 (13)	0.0017 (13)
C21	0.041 (2)	0.0272 (16)	0.0344 (17)	0.0027 (14)	−0.0046 (15)	0.0062 (13)
C22	0.075 (3)	0.054 (2)	0.043 (2)	−0.013 (2)	−0.021 (2)	0.0175 (18)
C23	0.097 (4)	0.066 (3)	0.050 (2)	−0.020 (3)	−0.008 (2)	0.032 (2)
C24	0.062 (3)	0.047 (2)	0.063 (3)	−0.012 (2)	−0.003 (2)	0.024 (2)
C25	0.049 (2)	0.0348 (19)	0.058 (2)	−0.0074 (17)	−0.0125 (18)	0.0151 (17)
C26	0.045 (2)	0.0376 (18)	0.0366 (18)	−0.0011 (16)	−0.0078 (16)	0.0107 (15)
C31	0.040 (2)	0.0348 (17)	0.0293 (16)	−0.0072 (15)	−0.0006 (14)	0.0036 (13)
C36	0.058 (3)	0.043 (2)	0.0355 (19)	−0.0063 (18)	0.0089 (17)	0.0019 (16)
C35	0.092 (4)	0.059 (3)	0.0291 (19)	−0.023 (3)	0.004 (2)	−0.0016 (18)
C34	0.082 (4)	0.075 (3)	0.039 (2)	−0.038 (3)	−0.020 (2)	0.017 (2)
C33	0.054 (3)	0.080 (3)	0.062 (3)	−0.011 (2)	−0.024 (2)	0.018 (2)
C32	0.045 (2)	0.067 (3)	0.045 (2)	0.002 (2)	−0.0100 (18)	0.0019 (19)
C41	0.0318 (17)	0.0318 (16)	0.0320 (16)	−0.0011 (14)	−0.0033 (14)	0.0020 (13)
C42	0.036 (2)	0.042 (2)	0.070 (3)	0.0016 (16)	0.0058 (19)	0.0162 (19)
C43	0.050 (2)	0.044 (2)	0.085 (3)	0.0119 (19)	−0.001 (2)	0.017 (2)
C44	0.074 (3)	0.040 (2)	0.068 (3)	0.007 (2)	−0.004 (2)	0.019 (2)
C45	0.080 (3)	0.049 (2)	0.067 (3)	0.000 (2)	0.020 (2)	0.021 (2)
C46	0.051 (2)	0.043 (2)	0.056 (2)	0.0066 (18)	0.0178 (19)	0.0138 (18)

Geometric parameters (Å, º)

N1—C2	1.513 (4)	C31—C32	1.385 (5)
N1—C4	1.536 (4)	C31—C36	1.387 (5)
N1—H12	0.82 (4)	C36—C35	1.392 (6)
N1—H11	0.84 (5)	C36—H36	0.9300
C2—C21	1.494 (5)	C35—C34	1.364 (7)
C2—C3	1.551 (4)	C35—H35	0.9300
C2—H2	0.88 (3)	C34—C33	1.366 (7)
C3—C31	1.501 (5)	C34—H34	0.9300
C3—C4	1.538 (5)	C33—C32	1.394 (6)
C3—H3	0.94 (4)	C33—H33	0.9300
C4—C41	1.498 (5)	C32—H32	0.9300
C4—H4	0.93 (4)	C41—C46	1.380 (5)
C21—C26	1.381 (5)	C41—C42	1.392 (5)
C21—C22	1.390 (5)	C42—C43	1.385 (6)
C22—C23	1.373 (6)	C42—H42	0.9300
C22—H22	0.9300	C43—C44	1.356 (6)
C23—C24	1.377 (6)	C43—H43	0.9300
C23—H23	0.9300	C44—C45	1.383 (7)
C24—C25	1.372 (6)	C44—H44	0.9300
C24—H24	0.9300	C45—C46	1.372 (6)
C25—C26	1.385 (5)	C45—H45	0.9300
C25—H25	0.9300	C46—H46	0.9300
C26—H26	0.9300
C2—N1—C4	89.0 (2)	C21—C26—C25	120.5 (3)
C2—N1—H12	115 (3)	C21—C26—H26	119.7
C4—N1—H12	112 (3)	C25—C26—H26	119.7
C2—N1—H11	116 (3)	C32—C31—C36	118.2 (3)
C4—N1—H11	114 (3)	C32—C31—C3	121.6 (3)
H12—N1—H11	110 (4)	C36—C31—C3	120.2 (3)
C21—C2—N1	119.5 (3)	C31—C36—C35	120.4 (4)
C21—C2—C3	119.4 (3)	C31—C36—H36	119.8
N1—C2—C3	88.5 (2)	C35—C36—H36	119.8
C21—C2—H2	107 (2)	C34—C35—C36	120.8 (4)
N1—C2—H2	105 (2)	C34—C35—H35	119.6
C3—C2—H2	115 (2)	C36—C35—H35	119.6
C31—C3—C4	119.3 (3)	C35—C34—C33	119.6 (4)
C31—C3—C2	120.8 (3)	C35—C34—H34	120.2
C4—C3—C2	87.6 (2)	C33—C34—H34	120.2
C31—C3—H3	111 (2)	C34—C33—C32	120.4 (5)
C4—C3—H3	109 (2)	C34—C33—H33	119.8
C2—C3—H3	107 (2)	C32—C33—H33	119.8
C41—C4—N1	118.0 (3)	C31—C32—C33	120.7 (4)
C41—C4—C3	123.2 (3)	C31—C32—H32	119.7
N1—C4—C3	88.2 (2)	C33—C32—H32	119.7
C41—C4—H4	111 (2)	C46—C41—C42	118.2 (3)
N1—C4—H4	104 (2)	C46—C41—C4	119.7 (3)
C3—C4—H4	109 (2)	C42—C41—C4	122.1 (3)
C26—C21—C22	118.5 (3)	C43—C42—C41	120.0 (4)
C26—C21—C2	123.9 (3)	C43—C42—H42	120.0
C22—C21—C2	117.6 (3)	C41—C42—H42	120.0
C23—C22—C21	120.7 (4)	C44—C43—C42	121.4 (4)
C23—C22—H22	119.6	C44—C43—H43	119.3
C21—C22—H22	119.6	C42—C43—H43	119.3
C22—C23—C24	120.4 (4)	C43—C44—C45	118.8 (4)
C22—C23—H23	119.8	C43—C44—H44	120.6
C24—C23—H23	119.8	C45—C44—H44	120.6
C25—C24—C23	119.4 (4)	C46—C45—C44	120.6 (4)
C25—C24—H24	120.3	C46—C45—H45	119.7
C23—C24—H24	120.3	C44—C45—H45	119.7
C24—C25—C26	120.4 (4)	C45—C46—C41	121.0 (4)
C24—C25—H25	119.8	C45—C46—H46	119.5
C26—C25—H25	119.8	C41—C46—H46	119.5
C4—N1—C2—C21	142.8 (3)	C4—C3—C31—C32	−67.7 (5)
C4—N1—C2—C3	19.5 (3)	C2—C3—C31—C32	38.4 (5)
C21—C2—C3—C31	94.1 (4)	C4—C3—C31—C36	111.0 (4)
N1—C2—C3—C31	−142.5 (3)	C2—C3—C31—C36	−142.8 (3)
C21—C2—C3—C4	−142.9 (3)	C32—C31—C36—C35	1.0 (6)
N1—C2—C3—C4	−19.5 (3)	C3—C31—C36—C35	−177.8 (3)
C2—N1—C4—C41	−146.8 (3)	C31—C36—C35—C34	−1.2 (6)
C2—N1—C4—C3	−19.7 (3)	C36—C35—C34—C33	0.6 (7)
C31—C3—C4—C41	−93.8 (4)	C35—C34—C33—C32	0.3 (7)
C2—C3—C4—C41	141.9 (3)	C36—C31—C32—C33	−0.1 (6)
C31—C3—C4—N1	143.5 (3)	C3—C31—C32—C33	178.6 (4)
C2—C3—C4—N1	19.2 (2)	C34—C33—C32—C31	−0.5 (7)
N1—C2—C21—C26	6.7 (5)	N1—C4—C41—C46	−104.4 (4)
C3—C2—C21—C26	113.2 (4)	C3—C4—C41—C46	147.9 (3)
N1—C2—C21—C22	−172.7 (3)	N1—C4—C41—C42	76.6 (4)
C3—C2—C21—C22	−66.2 (4)	C3—C4—C41—C42	−31.2 (5)
C26—C21—C22—C23	−1.8 (6)	C46—C41—C42—C43	−0.6 (6)
C2—C21—C22—C23	177.6 (4)	C4—C41—C42—C43	178.5 (4)
C21—C22—C23—C24	0.2 (8)	C41—C42—C43—C44	0.8 (7)
C22—C23—C24—C25	1.4 (7)	C42—C43—C44—C45	−1.0 (7)
C23—C24—C25—C26	−1.3 (7)	C43—C44—C45—C46	1.1 (7)
C22—C21—C26—C25	1.9 (5)	C44—C45—C46—C41	−1.0 (7)
C2—C21—C26—C25	−177.5 (3)	C42—C41—C46—C45	0.7 (6)
C24—C25—C26—C21	−0.4 (6)	C4—C41—C46—C45	−178.4 (4)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H12···Br	0.82 (4)	2.51 (4)	3.317 (3)	170 (4)
N1—H11···Br^i	0.84 (5)	2.70 (5)	3.331 (3)	133 (4)
N1—H11···Br^ii	0.84 (5)	2.99 (4)	3.619 (3)	133 (4)

Symmetry codes: (i) −x, −y+1, −z+1; (ii) x+1, y, z.