9-(2-Ethyl­phenoxy­carbon­yl)-10-methyl­acridinium trifluoro­methane­sulfonate

Damian Trzybiński; Karol Krzymiński; Artur Sikorski; Piotr Malecha; Jerzy Błażejowski

doi:10.1107/S1600536810008950

. 2010 Mar 13;66(Pt 4):o826–o827. doi: 10.1107/S1600536810008950

9-(2-Ethylphenoxycarbonyl)-10-methylacridinium trifluoromethanesulfonate

Damian Trzybiński ^a, Karol Krzymiński ^a, Artur Sikorski ^a, Piotr Malecha ^a, Jerzy Błażejowski ^a,^*

PMCID: PMC2984008 PMID: 21580656

Abstract

In the crystal structure of the title compound, C₂₃H₂₀NO₂ ⁺·CF₃SO₃ ⁻, the cations form inversion dimers through π–π interactions between the acridine ring systems. These dimers are further linked by C—H⋯π interactions. The cations and anions are connected by C—H⋯O and C—F⋯π interactions. The acridine and benzene ring systems are oriented at a dihedral angle of 20.8 (1)°. The carboxyl group is twisted at an angle of 66.2 (1)° relative to the acridine skeleton. The mean planes of adjacent acridine units are parallel in the lattice.

Related literature

For general background to 9-(phenoxycarbonyl)-10-alkylacridinium salts, see: Brown et al. (2009 ▶); Rak et al. (1999 ▶); Roda et al. (2003 ▶); Zomer & Jacquemijns (2001 ▶). For related structures, see: Sikorski et al. (2005a ▶,b ▶). For intermolecular interactions, see: Bianchi et al. (2004 ▶); Dorn et al. (2005 ▶); Hunter et al. (2001 ▶); Steiner (1999 ▶); Takahashi et al. (2001 ▶). For the synthesis, see: Niziołek et al. (2008 ▶); Sato (1996 ▶).

Experimental

Crystal data

C₂₃H₂₀NO₂ ⁺·CF₃O₃S⁻
M _r = 491.47
Triclinic,
a = 9.8519 (4) Å
b = 10.9533 (4) Å
c = 11.7805 (4) Å
α = 104.379 (3)°
β = 101.475 (3)°
γ = 109.983 (3)°
V = 1099.61 (7) Å³
Z = 2
Mo Kα radiation
μ = 0.21 mm⁻¹
T = 295 K
0.40 × 0.35 × 0.20 mm

Data collection

Oxford Diffraction Gemini R Ultra Ruby CCD diffractometer
21109 measured reflections
3914 independent reflections
2956 reflections with I > 2σ(I)
R _int = 0.039

Refinement

R[F ² > 2σ(F ²)] = 0.039
wR(F ²) = 0.116
S = 1.10
3914 reflections
309 parameters
H-atom parameters constrained
Δρ_max = 0.20 e Å⁻³
Δρ_min = −0.30 e Å⁻³

Data collection: CrysAlis CCD (Oxford Diffraction, 2008 ▶); cell refinement: CrysAlis RED (Oxford Diffraction, 2008 ▶); data reduction: CrysAlis RED; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008 ▶) and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810008950/ng2739sup1.cif

e-66-0o826-sup1.cif^{(22.9KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810008950/ng2739Isup2.hkl

e-66-0o826-Isup2.hkl^{(191.8KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

Cg4 is the centroid of the C18–C23 ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C2—H2⋯O28ⁱ	0.93	2.55	3.221 (2)	130
C5—H5⋯O28ⁱⁱ	0.93	2.56	3.222 (3)	129
C24—H24B⋯Cg4ⁱⁱⁱ	0.96	2.92	3.603 (2)	129
C26—H26A⋯O29ⁱⁱ	0.96	2.43	3.280 (3)	148
C26—H26C⋯Cg4ⁱⁱ	0.96	2.80	3.741 (2)	165

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) .

Table 2. C—F⋯π interactions (Å,°).

Cg1 and Cg3 are the centroids of the C9/N10/C11–C14 and C5–C8/C13/C14 rings, respectively.

X—I⋯J	I⋯J	X⋯J	X—I⋯J
C31—F32⋯Cg3^iv	3.474 (2)	4.003 (2)	103.67 (14)
C31—F33⋯Cg1^iv	3.241 (2)	4.087 (2)	121.73 (14)
C31—F34⋯Cg3^iv	3.762 (2)	4.003 (2)	90.62 (13)

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Symmetry code: (iv) −x + 1, −y + 2, −z + 1.

Table 3. π–π interactions (Å,°).

Cg1, Cg2 and Cg3 are the centroids of the C9/N10/C11–C14, C1–C4/C11/C12 and C5–C8/C13/C14 rings, respectively. CgI⋯CgJ is the distance between ring centroids. The dihedral angle is that between the planes of the rings I and J. CgI_Perp is the perpendicular distance of CgI from ring J. CgI_Offset is the distance between CgI and perpendicular projection of CgJ on ring I.

I	J	CgI⋯CgJ	Dihedral angle	CgI_Perp	CgI_Offset
1	1^v	4.022 (2)	0.00	3.571 (2)	1.850 (2)
1	3^v	3.702 (2)	1.80	3.532 (2)	1.109 (2)
2	3^v	3.965 (2)	4.29	3.451 (2)	1.960 (2)
3	1^v	3.702 (2)	1.80	3.544 (2)	1.070 (2)
3	2^v	3.965 (2)	4.29	3.566 (2)	1.733 (2)

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Symmetry code: (v) −x + 1, −y + 1, −z + 1.

Acknowledgments

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.

supplementary crystallographic information

Comment

9-(Phenoxycarbonyl)-10-alkylacridinium salts have long been known as chemiluminescent indicators or the chemiluminogenic fragments of chemiluminescent labels (Zomer & Jacquemijns, 2001). These compounds are commonly applied in assays of biologically and environmentally important entities such as antigens, antibodies, enzymes or DNA fragments (Roda et al., 2003; Brown et al., 2009). The reaction of the cations of these salts with hydrogen peroxide in alkaline media produces light. Our own investigations (Rak et al., 1999) and those of others (Zomer et al., 2001) have revealed that oxidation of acridinium chemiluminogens is accompanied by the removal of the phenoxycarbonyl fragment and the conversion of the remaining molecules to electronically excited, light-emitting 10-alkyl-9-acridinones. It has been found that the efficiency of chemiluminescence – crucial for analytical applications – is affected by the constitution of the phenyl fragment (Zomer & Jacquemijns, 2001). In the search for efficient chemiluminogens we undertook investigations on 9-(phenoxycarbonyl)-10-methylacridinium derivatives substituted in the phenyl fragment. Here we present the structure of one such derivative.

In the cation of the title compound (Fig. 1), the bond lengths and angles characterizing the geometry of the acridinium moiety are typical of acridine-based derivatives (Sikorski et al., 2005a,b). With respective average deviations from planarity of 0.022 (3) Å and 0.002 (3) Å, the acridine and benzene ring systems are oriented at 20.8 (1)°. The carboxyl group is twisted at an angle of 66.2 (1)° relative to the acridine skeleton. The mean planes of the adjacent acridine moieties are parallel (remain at an angle of 0.0 (1)°) in the lattice. The mutual arrangement of the carboxyl group relative to the acridine skeleton is similar in the compound investigated and its precursor – 2-ethylphenyl acridine-9-carboxylate (Sikorski et al., 2005a). On the other hand, the acridine and benzene ring systems are oriented quite differently in the compound investigated and its precursor.

In the crystal structure, the inversely oriented cations form dimers through multidirectional π–π interactions involving acridine moieties (Table 3, Fig. 2). These dimers are linked by C–H···O (Table 1, Fig. 2) and C–F···π (Table 2, Fig. 2) interactions to adjacent anions, and by C–H···π (Table 1, Fig. 2) interactions to neighboring cations. The C–H···O interactions are of the hydrogen bond type (Steiner, 1999; Bianchi et al. 2004). The C–H···π interactions should be of an attractive nature (Takahashi et al., 2001), like the C–F···π (Dorn et al., 2005) and the π–π (Hunter et al., 2001) interactions. The crystal structure is stabilized by a network of these short-range specific interactions and by long-range electrostatic interactions between ions.

Experimental

The compound was synthesized in three steps (Niziołek et al., 2008). First, 9-(chlorocarbonyl)-acridine was produced by treating acridine-9-carboxylic acid with a tenfold molar excess of thionyl chloride. Then, esterification with 2-ethylphenol was carried out in anhydrous dichloromethane in the presence of N,N-diethylethanamine and a catalytic amount of N,N-dimethyl-4-pyridinamine (room temperature, 15h) (Sato, 1996). The crude product was purified chromatographically (SiO₂, cyclohexane/ethyl acetate, 3/2 v/v). The 2-ethylphenyl acridine-9-carboxylate thus obtained was quaternarized with a five-fold molar excess of methyl trifluoromethanesulfonate dissolved in anhydrous dichloromethane. The crude 9-(2-ethylphenoxycarbonyl)-10-methylacridinium trifluoromethanesulfonate was dissolved in a small amount of ethanol, filtered and precipitated with a 25 v/v excess of diethyl ether. Yellow crystals suitable suitable for X-Ray investigations were grown from absolute ethanol solution (m.p. 470-471 K).