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Acta Cryst. (2009). E65, o30-o31    [ doi:10.1107/S1600536808039676 ]

9-Ethyl-10-methylacridinium trifluoromethanesulfonate

B. Zadykowicz, M. Wera, A. Sikorski and J. Blazejowski

Abstract top

In the molecule of the title compound, C16H16N+·CF3SO3-, the central ring adopts a flattened-boat conformation, and the two aromatic rings are oriented at a dihedral angle of 3.94 (2)°. In the crystal structure, weak intermolecular hydrogen bonds link the molecules. There are [pi]-[pi] contacts between the aromatic rings and the central ring and one of the aromatic rings [centroid-centroid distances = 3.874 (2), 3.945 (2) and 3.814 (2) Å]. There is also an S-O...[pi] contact between the central ring and one of the O atoms of the anion.

Comment top

Acridinium cations substituted in positions 9 and 10 are susceptible to attack by OOH- or other oxidants at C9, which initiates conversion of these cations to electronically excited-light emitting 9-acridinones (Zomer & Jacquemijns, 2001). We investigated the above described chemiluminescence in the case of 9-(phenoxycarbonyl)-10-methylacridinium trifluoromethanesulfonates, the several structures of which we recently determined (Sikorski et al., 2005a, b, c; Sikorski et al., 2006; Krzymiński et al., 2007; Sikorski et al., 2008). Chemiluminogenic features are also exhibited by the 9-cyano-10-methylacridinium and 9,10-dimethylacridinium cations respectively present as counterpart ions in hydrogen dinitrate and methylsulfate salts, the crystal structures of which were also refined (Huta et al., 2002; Meszko et al., 2002). We report herein the crystal structure of the title compound, which was selected for investigations as a potential chemiluminogen. The 9-ethyl-10-methylacridinium cation may also be interesting as a model compound in investigations of C-acidic features of organic molecules, since such properties are exhibited by the 9,10-dimethylacridinium cation (Suzuki & Tanaka, 2001).

In the molecule of the title compound (Fig. 1) the bond lengths and angles, characterizing the geometry of the acridine ring, are typical of acridine-based derivatives (Storoniak et al., 2000; Meszko et al., 2002). Rings A (C1-C4/C11/C12) and C (C5-C8/C13/C14) are planar and are oriented at a dihedral angle of 3.94 (2)°. Ring B (C9/N10/C11-C14) is not planar, having total puckering amplitude, QT, of 1.990 (5) and flattened-boat conformation [φ = 31.52 (5)° and θ = 21.87 (4)°] (Cremer & Pople, 1975).

In the crystal structure, weak intermolecular hydrogen bonds (Table 1) link the molecules. The central ring B and the aromatic ring A are involved in multidirectional π-π interactions (Table 2, Fig. 2). One of the O atoms of the anion is involved in weak S—O···π interactions directed toward the center of the acridine ring system (Table 3, Fig. 2). The C—H···O (Bianchi et al., 2004; Steiner, 1999) interactions are of the hydrogen-bond type. The S—O···π interactions (Dorn et al., 2005) should be of an attractive nature, such as is also exhibited by π-π interactions (Hunter & Sanders, 1990). The crystal structure is stabilized by a network of the aforementioned short-range interactions, as well as by long-range electrostatic interactions between ions.

Related literature top

For general background, see: Bianchi et al. (2004); Dorn et al. (2005); Hunter & Sanders (1990); Steiner (1991); Suzuki & Tanaka (2001); Zomer & Jacquemijns (2001). For related structures, see: Huta et al. (2002); Krzymiński et al. (2007); Meszko et al. (2002); Sikorski et al. (2005a,b,c, 2006, 2008); Storoniak et al. (2000); Tsuge et al. (1965). For ring puckering parameters, see: Cremer & Pople (1975).

Experimental top

9-Ethylacridine was synthesized by heating a mixture of N-phenylaniline with an equimolar amount of propanoic acid, both dispersed in molten zinc chloride (493 K, 26 h) (Tsuge et al., 1965). The crude product was purified by gravitational column chromatography (SiO2, n-hexane-ethyl acetate, 5:1 v/v). 9-Ethyl-10-methylacridinium trifluoromethanesulfonate was obtained by dissolving 9-ethylacridine with a fivefold molar excess of methyl trifluoromethanesulfonate in anhydrous dichloromethane and leaving the mixture for 3 h (Ar atmosphere, room temperature). The crude salt that precipitated was dissolved in a small amount of ethanol, filtered, and again precipitated with a 25 v/v excess of diethyl ether (yield; 89%). Pale-yellow crystals suitable for X-ray analysis were grown from absolute ethanol solution.

Refinement top

H atoms were positioned geometrically, with C-H = 0.93, 0.97 and 0.96 Å for aromatic, methylene and methyl H, respectively, and constrained to ride on their parent atoms with Uiso(H) = xUeq(C), where x = 1.5 for methyl H and x = 1.2 for all other H atoms.

Computing details top

Data collection: CrysAlis CCD (Oxford Diffraction, 2008); cell refinement: CrysAlis RED (Oxford Diffraction, 2008); data reduction: CrysAlis RED (Oxford Diffraction, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEPII (Johnson, 1976); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2003).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound showing the atom-labeling scheme. Displacement ellipsoids are drawn at the 25% probability level and H atoms are shown as small spheres of arbitrary radius. Cg1 and Cg2 denote the ring centroids.
[Figure 2] Fig. 2. The arrangement of the ions in the crystal structure. The C—H···O interactions are represented by dashed lines, the π-π and S—O···π interactions by dotted lines. H atoms not involved in the interactions have been omitted. [Symmetry codes: (i) x, y, z + 1; (ii) x, y - 1, z + 1; (iii) -x, -y + 2, -z + 1; (iv) -x, -y + 1, -z + 2; (v) -x + 1, -y + 1, -z + 2; (vi) -x + 1, -y + 1, -z + 1.]
9-Ethyl-10-methylacridinium trifluoromethanesulfonate top
Crystal data top
C16H16N+·CF3SO3−Z = 2
Mr = 371.37F(000) = 384
Triclinic, P1Dx = 1.515 Mg m−3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71073 Å
a = 7.771 (2) ÅCell parameters from 2857 reflections
b = 9.440 (2) Åθ = 3.1–25.0°
c = 11.898 (2) ŵ = 0.25 mm−1
α = 76.76 (3)°T = 295 K
β = 74.04 (3)°Plate, pale-yellow
γ = 82.14 (3)°0.5 × 0.5 × 0.05 mm
V = 814.3 (3) Å3
Data collection top
Oxford Diffraction GEMINI R ULTRA Ruby CCD
diffractometer		2857 independent reflections
Radiation source: Enhance (Mo) X-ray Source2078 reflections with I > 2σ(I)
graphiteRint = 0.020
Detector resolution: 10.4002 pixels mm-1θmax = 25.0°, θmin = 3.1°
ω scansh = −9→8
Absorption correction: multi-scan
(CrysAlis RED; Oxford Diffraction, 2008)		k = −8→11
Tmin = 0.870, Tmax = 0.988l = −13→14
7781 measured reflections
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.035H-atom parameters constrained
wR(F2) = 0.102 w = 1/[σ2(Fo2) + (0.0604P)2 + 0.0136P]
where P = (Fo2 + 2Fc2)/3
S = 1.08(Δ/σ)max < 0.001
2857 reflectionsΔρmax = 0.22 e Å−3
229 parametersΔρmin = −0.25 e Å−3
0 restraintsExtinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.014 (3)
Crystal data top
C16H16N+·CF3SO3−γ = 82.14 (3)°
Mr = 371.37V = 814.3 (3) Å3
Triclinic, P1Z = 2
a = 7.771 (2) ÅMo Kα radiation
b = 9.440 (2) ŵ = 0.25 mm−1
c = 11.898 (2) ÅT = 295 K
α = 76.76 (3)°0.5 × 0.5 × 0.05 mm
β = 74.04 (3)°
Data collection top
Oxford Diffraction GEMINI R ULTRA Ruby CCD
diffractometer		2857 independent reflections
Absorption correction: multi-scan
(CrysAlis RED; Oxford Diffraction, 2008)		2078 reflections with I > 2σ(I)
Tmin = 0.870, Tmax = 0.988Rint = 0.020
7781 measured reflectionsθmax = 25.0°
Refinement top
R[F2 > 2σ(F2)] = 0.035H-atom parameters constrained
wR(F2) = 0.102Δρmax = 0.22 e Å−3
S = 1.08Δρmin = −0.25 e Å−3
2857 reflectionsAbsolute structure: ?
229 parametersFlack parameter: ?
0 restraintsRogers parameter: ?
Special details top

Experimental. Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.

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
C10.3057 (2)0.6242 (2)0.97192 (18)0.0479 (5)
H10.34550.71720.94130.057*
C20.2727 (3)0.5708 (2)1.09064 (19)0.0541 (5)
H20.28760.62761.14110.065*
C30.2161 (3)0.4299 (2)1.13769 (19)0.0551 (5)
H30.19460.39401.21950.066*
C40.1918 (3)0.3445 (2)1.06641 (18)0.0490 (5)
H40.15710.25031.09930.059*
C50.1504 (3)0.2917 (2)0.68005 (19)0.0526 (5)
H50.10460.20130.71410.063*
C60.1686 (3)0.3478 (2)0.5618 (2)0.0616 (6)
H60.13400.29470.51590.074*
C70.2377 (3)0.4825 (2)0.50750 (19)0.0594 (6)
H70.25050.51750.42620.071*
C80.2859 (3)0.5621 (2)0.57323 (17)0.0509 (5)
H80.33120.65220.53640.061*
C90.3131 (2)0.59454 (18)0.76881 (17)0.0397 (4)
N100.18592 (19)0.31700 (15)0.86993 (13)0.0387 (4)
C110.2806 (2)0.54049 (18)0.89252 (17)0.0394 (4)
C120.2190 (2)0.39871 (18)0.94283 (16)0.0388 (4)
C130.2688 (2)0.51098 (19)0.69798 (16)0.0398 (4)
C140.2018 (2)0.37195 (19)0.75118 (17)0.0397 (4)
C150.1358 (3)0.1658 (2)0.92047 (19)0.0548 (5)
H15A0.18620.10640.86190.082*
H15B0.00740.16500.94260.082*
H15C0.18130.12770.98970.082*
C160.3835 (3)0.7413 (2)0.71458 (19)0.0492 (5)
H16A0.45360.74160.63330.059*
H16B0.46210.76010.75940.059*
C170.2316 (3)0.8623 (2)0.7141 (2)0.0590 (6)
H17A0.28080.95410.67530.088*
H17B0.16700.86650.79480.088*
H17C0.15150.84230.67200.088*
C180.2605 (3)0.9709 (2)0.36020 (18)0.0563 (5)
F190.12725 (18)0.89034 (15)0.42780 (11)0.0835 (4)
F200.19886 (19)1.11050 (15)0.35499 (12)0.0838 (4)
F210.3880 (2)0.94796 (18)0.41894 (12)0.0913 (5)
S220.34301 (7)0.92827 (5)0.21309 (4)0.0488 (2)
O230.4120 (2)0.77973 (17)0.23799 (17)0.0817 (5)
O240.18424 (19)0.95139 (17)0.17045 (13)0.0650 (4)
O250.47217 (19)1.03268 (17)0.15403 (13)0.0688 (5)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0441 (11)0.0382 (11)0.0692 (14)−0.0014 (8)−0.0219 (10)−0.0183 (10)
C20.0527 (13)0.0543 (13)0.0663 (14)0.0040 (10)−0.0248 (11)−0.0271 (11)
C30.0548 (13)0.0607 (14)0.0535 (12)0.0015 (10)−0.0206 (10)−0.0138 (10)
C40.0473 (12)0.0422 (11)0.0587 (13)−0.0025 (9)−0.0182 (9)−0.0072 (9)
C50.0559 (13)0.0417 (12)0.0660 (14)−0.0073 (9)−0.0171 (10)−0.0182 (10)
C60.0667 (15)0.0633 (15)0.0669 (15)−0.0079 (12)−0.0235 (12)−0.0275 (12)
C70.0609 (14)0.0682 (15)0.0523 (12)−0.0046 (11)−0.0177 (11)−0.0147 (11)
C80.0478 (12)0.0491 (12)0.0555 (13)−0.0064 (9)−0.0130 (10)−0.0083 (10)
C90.0296 (10)0.0320 (10)0.0584 (12)−0.0004 (7)−0.0121 (8)−0.0107 (8)
N100.0355 (8)0.0285 (8)0.0541 (10)−0.0026 (6)−0.0129 (7)−0.0103 (7)
C110.0288 (9)0.0336 (10)0.0600 (12)0.0019 (7)−0.0154 (8)−0.0155 (8)
C120.0305 (9)0.0329 (10)0.0557 (12)0.0018 (7)−0.0145 (8)−0.0124 (8)
C130.0318 (10)0.0346 (10)0.0540 (11)−0.0005 (7)−0.0108 (8)−0.0124 (8)
C140.0330 (10)0.0340 (10)0.0547 (12)0.0009 (7)−0.0125 (8)−0.0146 (8)
C150.0676 (14)0.0329 (11)0.0676 (13)−0.0116 (10)−0.0219 (11)−0.0070 (9)
C160.0468 (12)0.0394 (11)0.0621 (12)−0.0107 (9)−0.0124 (9)−0.0093 (9)
C170.0638 (14)0.0367 (12)0.0740 (14)−0.0036 (10)−0.0152 (11)−0.0091 (10)
C180.0564 (13)0.0557 (14)0.0565 (13)−0.0210 (11)−0.0115 (11)−0.0041 (10)
F190.0803 (10)0.0913 (11)0.0695 (9)−0.0423 (8)0.0020 (7)−0.0019 (7)
F200.0990 (11)0.0619 (9)0.0841 (9)−0.0101 (8)0.0033 (8)−0.0317 (7)
F210.0951 (11)0.1268 (13)0.0649 (9)−0.0367 (10)−0.0363 (8)−0.0091 (8)
S220.0461 (3)0.0466 (3)0.0603 (3)−0.0064 (2)−0.0172 (2)−0.0179 (2)
O230.0841 (12)0.0528 (10)0.1235 (14)0.0168 (8)−0.0476 (11)−0.0355 (9)
O240.0598 (9)0.0738 (10)0.0708 (9)−0.0122 (8)−0.0342 (8)−0.0078 (8)
O250.0612 (10)0.0840 (11)0.0630 (9)−0.0324 (8)0.0022 (7)−0.0248 (8)
Geometric parameters (Å, °) top
C1—C21.351 (3)N10—C141.366 (2)
C1—C111.428 (2)N10—C121.377 (2)
C1—H10.9300N10—C151.477 (2)
C2—C31.399 (3)C11—C121.424 (2)
C2—H20.9300C13—C141.421 (3)
C3—C41.359 (3)C15—H15A0.9600
C3—H30.9300C15—H15B0.9600
C4—C121.408 (3)C15—H15C0.9600
C4—H40.9300C16—C171.526 (3)
C5—C61.360 (3)C16—H16A0.9700
C5—C141.418 (3)C16—H16B0.9700
C5—H50.9300C17—H17A0.9600
C6—C71.394 (3)C17—H17B0.9600
C6—H60.9300C17—H17C0.9600
C7—C81.351 (3)F19—C181.332 (2)
C7—H70.9300F20—C181.333 (3)
C8—C131.426 (3)F21—C181.331 (2)
C8—H80.9300S22—O251.4276 (15)
C9—C111.406 (3)S22—O241.4308 (14)
C9—C131.411 (2)S22—C181.809 (2)
C9—C161.496 (3)O23—S221.4257 (16)
C2—C1—C11121.23 (19)C9—C13—C14119.89 (17)
C2—C1—H1119.4C9—C13—C8122.18 (17)
C11—C1—H1119.4C14—C13—C8117.92 (16)
C1—C2—C3120.02 (18)N10—C14—C5120.50 (17)
C1—C2—H2120.0N10—C14—C13120.14 (15)
C3—C2—H2120.0C5—C14—C13119.36 (18)
C4—C3—C2121.4 (2)N10—C15—H15A109.5
C4—C3—H3119.3N10—C15—H15B109.5
C2—C3—H3119.3H15A—C15—H15B109.5
C3—C4—C12120.01 (19)N10—C15—H15C109.5
C3—C4—H4120.0H15A—C15—H15C109.5
C12—C4—H4120.0H15B—C15—H15C109.5
C6—C5—C14119.59 (19)C9—C16—C17111.60 (16)
C6—C5—H5120.2C9—C16—H16A109.3
C14—C5—H5120.2C17—C16—H16A109.3
C5—C6—C7121.87 (18)C9—C16—H16B109.3
C5—C6—H6119.1C17—C16—H16B109.3
C7—C6—H6119.1H16A—C16—H16B108.0
C8—C7—C6119.9 (2)C16—C17—H17A109.5
C8—C7—H7120.1C16—C17—H17B109.5
C6—C7—H7120.1H17A—C17—H17B109.5
C7—C8—C13121.37 (19)C16—C17—H17C109.5
C7—C8—H8119.3H17A—C17—H17C109.5
C13—C8—H8119.3H17B—C17—H17C109.5
C11—C9—C13118.54 (16)F21—C18—F19106.83 (16)
C11—C9—C16120.65 (16)F21—C18—F20106.57 (17)
C13—C9—C16120.72 (17)F19—C18—F20107.29 (19)
C14—N10—C12121.38 (15)F21—C18—S22112.10 (16)
C14—N10—C15119.21 (14)F19—C18—S22112.04 (14)
C12—N10—C15119.40 (16)F20—C18—S22111.67 (14)
C9—C11—C12120.23 (15)O23—S22—O25116.29 (11)
C9—C11—C1122.06 (17)O23—S22—O24115.01 (10)
C12—C11—C1117.71 (18)O25—S22—O24114.73 (10)
N10—C12—C4120.96 (17)O23—S22—C18102.68 (11)
N10—C12—C11119.48 (17)O25—S22—C18102.77 (9)
C4—C12—C11119.55 (16)O24—S22—C18102.49 (10)
C11—C1—C2—C31.2 (3)C16—C9—C13—C8−0.9 (3)
C1—C2—C3—C4−0.5 (3)C7—C8—C13—C9−177.97 (18)
C2—C3—C4—C12−1.7 (3)C7—C8—C13—C141.0 (3)
C14—C5—C6—C70.3 (3)C12—N10—C14—C5−173.83 (16)
C5—C6—C7—C8−1.1 (3)C15—N10—C14—C57.4 (3)
C6—C7—C8—C130.4 (3)C12—N10—C14—C135.7 (2)
C13—C9—C11—C125.4 (2)C15—N10—C14—C13−173.07 (16)
C16—C9—C11—C12−178.00 (15)C6—C5—C14—N10−179.46 (17)
C13—C9—C11—C1−174.00 (16)C6—C5—C14—C131.0 (3)
C16—C9—C11—C12.6 (3)C9—C13—C14—N10−2.2 (3)
C2—C1—C11—C9179.61 (16)C8—C13—C14—N10178.83 (16)
C2—C1—C11—C120.2 (3)C9—C13—C14—C5177.31 (17)
C14—N10—C12—C4176.08 (16)C8—C13—C14—C5−1.7 (3)
C15—N10—C12—C4−5.2 (2)C11—C9—C16—C17−87.9 (2)
C14—N10—C12—C11−3.5 (2)C13—C9—C16—C1788.5 (2)
C15—N10—C12—C11175.24 (16)O23—S22—C18—F2156.86 (17)
C3—C4—C12—N10−176.51 (16)O25—S22—C18—F21−64.24 (17)
C3—C4—C12—C113.1 (3)O24—S22—C18—F21176.45 (14)
C9—C11—C12—N10−2.2 (2)O23—S22—C18—F19−63.24 (18)
C1—C11—C12—N10177.29 (15)O25—S22—C18—F19175.66 (15)
C9—C11—C12—C4178.25 (16)O24—S22—C18—F1956.35 (18)
C1—C11—C12—C4−2.3 (2)O23—S22—C18—F20176.37 (14)
C11—C9—C13—C14−3.3 (3)O25—S22—C18—F2055.27 (17)
C16—C9—C13—C14−179.86 (15)O24—S22—C18—F20−64.04 (16)
C11—C9—C13—C8175.63 (15)
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
C2—H2···O23i0.932.473.369 (3)164
C15—H15C···O24ii0.962.403.276 (3)151
C16—H16B···O25iii0.972.583.377 (3)140
Symmetry codes: (i) x, y, z+1; (ii) x, y−1, z+1; (iii) −x+1, −y+2, −z+1.
Table 1
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
C2—H2···O23i0.932.473.369 (3)164
C15—H15C···O24ii0.962.403.276 (3)151
C16—H16B···O25iii0.972.583.377 (3)140
Symmetry codes: (i) x, y, z+1; (ii) x, y−1, z+1; (iii) −x+1, −y+2, −z+1.
Table 2
π–π Interactions (Å, °). top
CgICgJCg···CgDihedral angleInterplanar distanceOffset
12iv3.814 (2)3.883.517 (2)5.188
21iv3.814 (2)3.883.542 (2)5.205
22iv3.945 (2)0.023.578 (2)5.326
22v3.874 (2)0.023.440 (2)5.181
Symmetry codes: (iv) -x, -y+1, -z+2; (v) -x+1, -y+1, -z+2.

Notes: Cg1 is the centroid of ring B (C9/N10/C11-C14), Cg2 is the centroid of ring A (C1-C4/C11/C12). Cg···Cg is the distance between ring centroids. The dihedral angle is that between the planes of the rings CgI and CgJ. The interplanar distance is the perpendicular distance of CgI from ring J. The offset is the perpendicular distance of ring I from ring J.
Table 3
S—O···π Interactions (Å, °). top
XIJI···JX···JX-I···J
S22O231vi3.255 (2)3.072 (2)146
Symmetry codes: (vi) -x+1, -y+1, -z+1.

Notes: Cg1 is the centroid of ring B (C9/N10/C11-C14).
Acknowledgements top

This study was financed by the State Funds for Scientific Research (grant No. N204 123 32/3143, contract No. 3143/H03/ 2007/32 of the Polish Ministry of Research and Higher Education) for the period 2007–2010.

references
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