A new tribridged imidazolium cyclo­phane

The new imidazolium cyclo­phane 2,11,13,21,29,31-hexamethyl-5,16,24-tri­aza-8,19,27-triazoniahepta­cyclo[10.10.6.1^1,3.­1^5,8.1^10,14.1^16,19.1^24,27]­tritriaconta-1,3(29),6,8(30),10,­12,14(31),17,19(32),21,25,27(33)-dodecene tri­bromide dihydrate, C₃₃H₃₉N₆³⁺.3Br^-.2H₂O, belongs to a type of cyl­indrical macrobicyclic salt containing imidazolium groups. It has mirror symmetry, the symmetry surface is the plane of the three 2-C atoms of imidazoliums. Three bromine anions are associated with two water mol­ecules by hydrogen bonds. The O-H...Br bond lengths are 2.53 (3) and 2.46 (3) Å.

S1. Comment

The molecular recognition and catalysis properties of cyclophanes have received considerable attention in recent years (Lehn, 1995). It is worthwhile pursuing to design and prepare suitable macrocyclic ligands with fine features. Following our work on imidazole-containing macrocycles (Liu et al., 1999; Lou et al., 1995), for the first time, we synthesize the new type of cyclophane in which two benzene rings are triply bridged by imidazoliums, (I). The compound has C_s symmetry. The parallel capping benzene rings are 5.144 Å apart. The three imidazolium rings are not arranged symmetrically, the angles of them are 54.0, 99.1 and 153.2°, and the distances of the three 2-carbons of the imidazoliums are 4.703, 4.711 and 4.514 Å. The shape of the compound makes it suitable to form exclusive or inclusive complexes with small anions.

Different from the case of [1₄]metacyclo-bis-(1,3)imidazolophanium dichloride dihydrate (Alcalde et al., 1999), the halogen anions form hydrogen bonds with water rather than with imidazolophanium.

S2. Experimental

The title compound was prepared by the dropwise addition of 1,3,5-trimethyl-2,4,6-tris(bromomethyl)benzene to 1,3,5-trimethyl-2,4,6-tri(imidazolymethyl) benzene in highly diluted acetonitrile solutions at 348 K and recrystallized from water.

S3. Refinement

The absorption correction is given by the experimental fact, so it is appropriate. The difference between expected and reported T_max/T_min may be caused by the fact that the single-crystal is not quite perfect or the measurement of the crystal size is not very precise. The water H atoms H1A and H1B were refined.

Computing details

Data collection: XSCANS (Siemens, 1996); cell refinement: XSCANS (Siemens, 1996); data reduction: SHELXTL (Siemens, 1994); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Siemens, 1994); software used to prepare material for publication: SHELXTL (Siemens, 1994).

2,11,13,21,29,31-hexamethyl-5,16,24-triaza-8,19,27-triazoniaheptacyclo- [10.10.6.1^1,3.1^5,8.1^10,14.1^16,19.1^24,27]tritriaconta- 1,3(29),6,8(30),10,12,14 (31),17,19 (32),21,25,27 (33)-dodecene tribromide dihydrate

Crystal data

C33H39N6^3+·3Br^−·2H2O	Dx = 1.602 Mg m^−3
Mr = 795.46	Melting point > 573 K
Monoclinic, P21/m	Mo Kα radiation, λ = 0.71073 Å
a = 9.855 (2) Å	Cell parameters from 29 reflections
b = 17.306 (3) Å	θ = 3.2–16.4°
c = 10.607 (2) Å	µ = 3.71 mm^−1
β = 114.29 (1)°	T = 296 K
V = 1648.9 (5) Å^3	Flake, colourless
Z = 2	0.56 × 0.40 × 0.28 mm
F(000) = 808

Data collection

Siemens P4 diffractometer	2006 reflections with I > 2σ(I)
Radiation source: normal-focus sealed tube	Rint = 0.022
Graphite monochromator	θmax = 25°, θmin = 2.1°
ω scans	h = 0→11
Absorption correction: empirical (using intensity measurements) (SHELXTL; Siemems, 1994)	k = −1→20
Tmin = 0.227, Tmax = 0.354	l = −12→11
3533 measured reflections	3 standard reflections every 97 reflections
2989 independent reflections	intensity decay: 5.4%

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)] = 0.034	H-atom parameters constrained
wR(F^2) = 0.073	w = 1/[σ^2(Fo^2) + (0.0376P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 0.88	(Δ/σ)max = 0.001
2989 reflections	Δρmax = 0.41 e Å^−3
217 parameters	Δρmin = −0.45 e Å^−3
3 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: 0.0033 (4)

Special details

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
Br1	0.60411 (4)	−0.04704 (2)	0.27542 (4)	0.03738 (14)
Br2	0.68478 (8)	0.2500	0.34559 (7)	0.0586 (2)
N1	0.3727 (3)	0.18781 (15)	0.0343 (3)	0.0246 (6)
N2	0.0796 (3)	0.18738 (16)	0.4093 (3)	0.0294 (7)
N3	−0.2540 (3)	0.18748 (15)	−0.2009 (3)	0.0266 (7)
C1	0.4272 (3)	0.21116 (18)	−0.0585 (3)	0.0289 (8)
H1	0.4585	0.1793	−0.1119	0.035*
C2	0.3421 (5)	0.2500	0.0904 (5)	0.0282 (12)
H2	0.3052	0.2500	0.1582	0.034*
C3	0.3499 (4)	0.10763 (18)	0.0691 (4)	0.0285 (9)
H3A	0.4301	0.0928	0.1561	0.034*
H3B	0.3507	0.0728	−0.0022	0.034*
C4	0.1563 (4)	0.2112 (2)	0.5422 (4)	0.0477 (11)
H4	0.2007	0.1795	0.6192	0.057*
C5	0.0334 (6)	0.2500	0.3306 (5)	0.0332 (13)
H5	−0.0224	0.2500	0.2354	0.040*
C6	0.0517 (4)	0.10673 (18)	0.3586 (4)	0.0334 (9)
H6A	−0.0453	0.0902	0.3513	0.040*
H6B	0.1262	0.0730	0.4238	0.040*
C7	−0.3782 (4)	0.2114 (2)	−0.3113 (3)	0.0414 (10)
H7	−0.4500	0.1797	−0.3751	0.050*
C8	−0.1814 (6)	0.2500	−0.1362 (5)	0.0328 (13)
H8	−0.0928	0.2500	−0.0571	0.039*
C9	−0.2092 (4)	0.10568 (18)	−0.1630 (4)	0.0295 (9)
H9A	−0.1926	0.0807	−0.2373	0.035*
H9B	−0.2885	0.0783	−0.1502	0.035*
C10	0.2014 (4)	0.10158 (17)	0.0810 (4)	0.0231 (8)
C11	0.1973 (4)	0.10027 (18)	0.2113 (4)	0.0249 (8)
C12	0.0575 (4)	0.10082 (17)	0.2187 (4)	0.0252 (8)
C13	−0.0758 (4)	0.10057 (17)	0.0980 (4)	0.0258 (8)
C14	−0.0678 (4)	0.10195 (17)	−0.0305 (4)	0.0258 (8)
C15	0.0699 (4)	0.10317 (17)	−0.0407 (3)	0.0246 (8)
C16	0.0764 (4)	0.1110 (2)	−0.1794 (4)	0.0380 (10)
H16A	0.0599	0.1639	−0.2088	0.046*
H16B	0.0009	0.0791	−0.2457	0.046*
H16C	0.1725	0.0948	−0.1722	0.046*
C17	0.3393 (4)	0.1013 (2)	0.3419 (4)	0.0405 (10)
H17A	0.3919	0.0536	0.3499	0.049*
H17B	0.3157	0.1075	0.4206	0.049*
H17C	0.4007	0.1436	0.3382	0.049*
C18	−0.2246 (4)	0.1027 (2)	0.1085 (4)	0.0411 (10)
H18A	−0.2336	0.0582	0.1585	0.049*
H18B	−0.3035	0.1026	0.0173	0.049*
H18C	−0.2308	0.1488	0.1563	0.049*
O	0.7795 (5)	0.0838 (3)	0.5175 (4)	0.0864 (12)
H1A	0.727 (6)	0.050 (2)	0.456 (5)	0.12 (2)*
H1B	0.749 (6)	0.1280 (15)	0.490 (5)	0.11 (2)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.0415 (2)	0.0325 (2)	0.0391 (2)	0.0034 (2)	0.01750 (18)	−0.0009 (2)
Br2	0.0587 (5)	0.0560 (4)	0.0591 (5)	0.000	0.0222 (4)	0.000
N1	0.0242 (15)	0.0233 (15)	0.0270 (16)	0.0021 (13)	0.0112 (13)	−0.0005 (13)
N2	0.0365 (17)	0.0279 (16)	0.0287 (16)	0.0022 (14)	0.0183 (15)	0.0015 (14)
N3	0.0247 (16)	0.0249 (15)	0.0254 (16)	−0.0004 (14)	0.0054 (14)	−0.0010 (14)
C1	0.0297 (19)	0.0325 (18)	0.0298 (19)	−0.0001 (16)	0.0175 (17)	−0.0006 (16)
C2	0.030 (3)	0.030 (3)	0.028 (3)	0.000	0.016 (3)	0.000
C3	0.033 (2)	0.0192 (17)	0.032 (2)	0.0037 (16)	0.0124 (18)	0.0017 (16)
C4	0.075 (3)	0.044 (2)	0.018 (2)	0.002 (2)	0.014 (2)	0.0042 (18)
C5	0.046 (4)	0.026 (3)	0.026 (3)	0.000	0.013 (3)	0.000
C6	0.041 (2)	0.0252 (19)	0.036 (2)	−0.0013 (17)	0.017 (2)	0.0021 (17)
C7	0.035 (2)	0.037 (2)	0.029 (2)	−0.0045 (18)	−0.0104 (18)	−0.0018 (17)
C8	0.029 (3)	0.026 (3)	0.032 (3)	0.000	0.002 (3)	0.000
C9	0.031 (2)	0.0199 (18)	0.034 (2)	−0.0016 (16)	0.0095 (18)	−0.0030 (16)
C10	0.0250 (19)	0.0159 (16)	0.031 (2)	0.0018 (14)	0.0143 (17)	0.0039 (15)
C11	0.025 (2)	0.0186 (18)	0.029 (2)	0.0029 (15)	0.0101 (17)	0.0042 (15)
C12	0.035 (2)	0.0170 (17)	0.027 (2)	0.0011 (15)	0.0156 (17)	0.0025 (15)
C13	0.030 (2)	0.0142 (17)	0.035 (2)	0.0018 (15)	0.0145 (18)	0.0039 (15)
C14	0.031 (2)	0.0134 (16)	0.029 (2)	−0.0004 (15)	0.0082 (17)	−0.0004 (15)
C15	0.028 (2)	0.0164 (17)	0.027 (2)	−0.0001 (15)	0.0102 (17)	0.0009 (15)
C16	0.037 (2)	0.042 (2)	0.033 (2)	−0.0016 (19)	0.0123 (19)	0.0013 (19)
C17	0.036 (2)	0.051 (2)	0.033 (2)	0.004 (2)	0.0123 (19)	0.0009 (19)
C18	0.032 (2)	0.050 (2)	0.043 (2)	0.0026 (19)	0.017 (2)	0.001 (2)
O	0.110 (3)	0.064 (2)	0.049 (2)	−0.007 (3)	−0.004 (2)	−0.004 (2)

Geometric parameters (Å, º)

N1—C2	1.323 (4)	C6—C12	1.511 (5)
N1—C1	1.362 (4)	C7—C7^i	1.335 (7)
N1—C3	1.477 (4)	C8—N3^i	1.323 (4)
N2—C5	1.329 (4)	C9—C14	1.520 (5)
N2—C4	1.361 (4)	C10—C11	1.400 (4)
N2—C6	1.480 (4)	C10—C15	1.404 (4)
N3—C8	1.323 (4)	C11—C12	1.412 (5)
N3—C7	1.365 (4)	C11—C17	1.511 (5)
N3—C9	1.488 (4)	C12—C13	1.408 (5)
C1—C1^i	1.344 (6)	C13—C14	1.397 (5)
C2—N1^i	1.323 (4)	C13—C18	1.516 (5)
C3—C10	1.524 (5)	C14—C15	1.404 (5)
C4—C4^i	1.343 (7)	C15—C16	1.505 (5)
C5—N2^i	1.329 (4)
C2—N1—C1	108.3 (3)	C11—C10—C15	121.2 (3)
C2—N1—C3	124.5 (3)	C11—C10—C3	120.1 (3)
C1—N1—C3	127.2 (3)	C15—C10—C3	118.6 (3)
C5—N2—C4	107.7 (3)	C10—C11—C12	118.7 (3)
C5—N2—C6	125.2 (3)	C10—C11—C17	120.9 (3)
C4—N2—C6	127.1 (3)	C12—C11—C17	120.4 (3)
C8—N3—C7	107.4 (3)	C13—C12—C11	121.1 (3)
C8—N3—C9	126.9 (3)	C13—C12—C6	119.7 (3)
C7—N3—C9	125.6 (3)	C11—C12—C6	119.1 (3)
C1^i—C1—N1	107.25 (17)	C14—C13—C12	118.8 (3)
N1—C2—N1^i	108.9 (4)	C14—C13—C18	121.0 (3)
N1—C3—C10	109.6 (3)	C12—C13—C18	120.1 (3)
C4^i—C4—N2	107.6 (2)	C13—C14—C15	121.3 (3)
N2^i—C5—N2	109.3 (4)	C13—C14—C9	120.3 (3)
N2—C6—C12	110.1 (3)	C15—C14—C9	118.4 (3)
C7^i—C7—N3	107.69 (19)	C10—C15—C14	119.0 (3)
N3—C8—N3^i	109.8 (4)	C10—C15—C16	120.4 (3)
N3—C9—C14	110.3 (3)	C14—C15—C16	120.5 (3)
C2—N1—C1—C1^i	−0.7 (3)	C10—C11—C12—C13	1.7 (5)
C3—N1—C1—C1^i	179.2 (3)	C17—C11—C12—C13	179.4 (3)
C1—N1—C2—N1^i	1.2 (5)	C10—C11—C12—C6	−174.5 (3)
C3—N1—C2—N1^i	−178.8 (2)	C17—C11—C12—C6	3.2 (5)
C2—N1—C3—C10	42.2 (5)	N2—C6—C12—C13	−99.0 (4)
C1—N1—C3—C10	−137.7 (3)	N2—C6—C12—C11	77.3 (4)
C5—N2—C4—C4^i	−0.4 (3)	C11—C12—C13—C14	−1.8 (5)
C6—N2—C4—C4^i	179.4 (3)	C6—C12—C13—C14	174.4 (3)
C4—N2—C5—N2^i	0.6 (6)	C11—C12—C13—C18	−178.8 (3)
C6—N2—C5—N2^i	−179.2 (3)	C6—C12—C13—C18	−2.6 (5)
C5—N2—C6—C12	36.3 (5)	C12—C13—C14—C15	0.3 (5)
C4—N2—C6—C12	−143.3 (4)	C18—C13—C14—C15	177.3 (3)
C8—N3—C7—C7^i	0.1 (3)	C12—C13—C14—C9	−177.0 (3)
C9—N3—C7—C7^i	−179.2 (3)	C18—C13—C14—C9	0.0 (5)
C7—N3—C8—N3^i	−0.2 (5)	N3—C9—C14—C13	88.2 (4)
C9—N3—C8—N3^i	179.1 (2)	N3—C9—C14—C15	−89.2 (4)
C8—N3—C9—C14	3.1 (5)	C11—C10—C15—C14	−1.2 (5)
C7—N3—C9—C14	−177.7 (3)	C3—C10—C15—C14	−176.5 (3)
N1—C3—C10—C11	−101.5 (3)	C11—C10—C15—C16	175.1 (3)
N1—C3—C10—C15	73.8 (4)	C3—C10—C15—C16	−0.2 (4)
C15—C10—C11—C12	−0.2 (5)	C13—C14—C15—C10	1.2 (5)
C3—C10—C11—C12	175.0 (3)	C9—C14—C15—C10	178.5 (3)
C15—C10—C11—C17	−177.9 (3)	C13—C14—C15—C16	−175.2 (3)
C3—C10—C11—C17	−2.6 (5)	C9—C14—C15—C16	2.2 (5)

Symmetry code: (i) x, −y+1/2, z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O—H1A···Br1	0.87 (3)	2.46 (3)	3.326 (4)	173 (5)
O—H1B···Br2	0.83 (2)	2.53 (3)	3.326 (4)	161 (5)