9-[(2,6-Dimethoxy­phen­oxy)carbon­yl]-10-methyl­acridinium trifluoro­methane­sulfonate

Karol Krzymiński; Damian Trzybiński; Artur Sikorski; Jerzy Błażejowski

doi:10.1107/S1600536809007570

. 2009 Mar 19;65(Pt 4):o789–o790. doi: 10.1107/S1600536809007570

9-[(2,6-Dimethoxyphenoxy)carbonyl]-10-methylacridinium trifluoromethanesulfonate

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

PMCID: PMC2968902 PMID: 21582514

Abstract

In the crystal structure of the title compound, C₂₃H₂₀NO₄ ⁺·CF₃SO₃ ⁻, the cations are linked through C—H⋯O, C—H⋯π and π–π interactions [centroid-centroid distances = 3.641 (2) and 3.885 (2) Å]. The cation and the anion are held together by C—H⋯O and S—O⋯π interactions. The acridine ring system and the benzene ring in the cation are oriented at a dihedral angle of 8.7 (1)°. The carboxy group is twisted at an angle of 83.2 (1)° relative to the acridine skeleton.

Related literature

For general background, see: Adamczyk et al. (2004 ▶); Becker et al. (1999 ▶); Rak et al. (1999 ▶); Zomer & Jacquemijns (2001 ▶). For related structures, see: Sikorski et al. (2008 ▶). For molecular interactions, see: Bianchi et al. (2004 ▶); Dorn et al. (2005 ▶); Hunter et al. (2001 ▶); Steiner (1999 ▶); Takahashi et al. (2001 ▶). For the synthesis, see: Sato (1996 ▶).

Experimental

Crystal data

C₂₃H₂₀NO₄ ⁺·CF₃SO₃ ⁻
M _r = 523.48
Monoclinic,
a = 11.6803 (4) Å
b = 14.7434 (5) Å
c = 13.6286 (5) Å
β = 93.462 (4)°
V = 2342.66 (14) Å³
Z = 4
Mo Kα radiation
μ = 0.21 mm⁻¹
T = 295 K
0.55 × 0.30 × 0.02 mm

Data collection

Oxford Diffraction Gemini R Ultra Ruby CCD diffractometer
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2008 ▶) T _min = 0.911, T _max = 0.995
20680 measured reflections
4160 independent reflections
2274 reflections with I > 2σ(I)
R _int = 0.045

Refinement

R[F ² > 2σ(F ²)] = 0.039
wR(F ²) = 0.109
S = 0.87
4160 reflections
328 parameters
H-atom parameters constrained
Δρ_max = 0.24 e Å⁻³
Δρ_min = −0.29 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 and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809007570/is2390sup1.cif

e-65-0o789-sup1.cif^{(23.5KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809007570/is2390Isup2.hkl

e-65-0o789-Isup2.hkl^{(203.9KB, hkl)}

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

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C3—H3⋯O30ⁱ	0.93	2.57	3.449 (3)	158
C4—H4⋯O31ⁱ	0.93	2.58	3.352 (3)	141
C7—H7⋯O32ⁱⁱ	0.93	2.54	3.427 (3)	159
C27—H27C⋯O17ⁱⁱⁱ	0.96	2.46	3.371 (3)	159
C25—H25C⋯Cg4^iv	0.96	2.98	3.845 (3)	150

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) ; (iv) . Cg4 is the centroid of the C18–C23 ring.

Table 2. S—O⋯π Interactions (Å,°).

X	I	J	I⋯J	X⋯J	X—I⋯J
S29	O32	Cg1^v	3.178 (2)	3.757 (2)	103

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Symmetry codes: (v) –x+1, –y+1, –z+1. Cg1 is the centroid of the C9/N10/C11–C14 ring.

Table 3. π–π Interactions (Å,°).

I	J	CgI⋯CgJ	Dihedral angle	CgI_Perp	CgJ_Perp	CgI_Offset	CgJ_Offset
1	4ⁱⁱ	3.641 (2)	5.31 (10)	3.416 (2)	3.492 (2)	0.767 (2)	1.031 (2)
2	4ⁱⁱ	3.885 (2)	6.74 (11)	3.666 (2)	3.491 (2)	1.286 (2)	1.705 (2)

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Symmetry code: (ii) Inline graphic . Notes: Cg1, Cg2 and Cg4 are the centroids of the C9/N10/C11–C14, C1–C4/C11/C12 and C18–C23 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 and CgJ _Perp are the perpendicular distances of CgI from ring J and of CgJ from ring I, respectively. CgI _Offset and CgJ _Offset are the distances between CgI and the perpendicular projection of CgJ on ring I, and between CgJ and the perpendicular projection of CgI on ring J, respectively.

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

Phenyl 10-alkylacridinium-9-carboxylates have long been known as chemiluminescent indicators or the chemiluminogenic fragments of chemiluminescent labels (Zomer & Jacquemijns, 2001). These compounds are widely applied in assays of biologically and environmentally important entities such as antigens, antibodies, enzymes or DNA fragments (Becker et al., 1999; Adamczyk et al., 2004). 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 & Jacquemijns, 2001) have revealed that oxidation of acridinium chemiluminogens is accompanied by the removal of the phenoxycarbonyl fragment and the convertion of the rest of molecules to electronically excited, light-emitting 10-alkyl-9-acridinones. It has been found that the efficiency of chemiluminescence is affected by the constitution of the phenyl fragment (Zomer & Jacquemijns, 2001). Continuing our investigations onto the above mentioned effect, we synthesized the compound containing two methoxy groups in the phenyl fragment. Here, we present its structure. Methoxy groups, which possess electron-attractive features, may influence the stability and chemiluminogenic ability of the compound investigated.

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., 2008). With respective average deviations from planarity of 0.037 (3) Å and 0.010 (3) Å, the acridine and benzene ring systems in the cation are oriented at 8.7 (1)°. The carboxy group is twisted at an angle of 83.2 (1)° relative to the acridine skeleton. The mean planes of the adjacent acridine moieties are either parallel or inclined at an angle of 10.9 (1)° in the lattice.

In the crystal structure, the cations are linked through C—H···O (Table 1, Fig. 2), C—H···π (Table 1, Fig. 2) and π–π (Table 3, Fig. 2) interactions, and the cations and anions by C—H···O (Table 1, Fig. 2) and S—O···π (Table 2, Fig. 2) interactions. The C—H···O (Steiner, 1999; Bianchi et al., 2004) interactions are of the hydrogen-bond type. The C—H···π (Takahashi et al., 2001) and S—O···π (Dorn et al., 2005) interactions should be of an attractive nature, like the π–π contacts (Hunter et al., 2001). The crystal structure is stabilized by a network of the aforementioned short-range specific interactions and by long-range electrostatic interactions between ions.

Experimental

2,6-Dimethoxyphenylacridine-9-carboxylate was prepared by heating anhydrous acridine-9-carboxylic acid with thionyl chloride, followed by esterification of the resulting acid chloride with an equimolar quantity of 2,6-dimethoxyphenol (Sato, 1996). The reaction was carried out in anhydrous dichloromethane in the presence of N,N-diethylethanamine (1.5 molar excess) and a catalytic amount of N,N-dimethyl-4-pyridinamine (room temperature, 15 - 25 h). The crude product was purified chromatographically (SiO₂, cyclohexane/ethyl acetate, 3/2 v/v). The 2,6-dimethoxyphenylacridine-9-carboxylate thus obtained was subsequently dissolved in anhydrous dichloromethane and treated with a fivefold molar excess of methyl triluoromethanesulfonate dissolved in the same solvent (under an Ar atmosphere at room temperature for 4 h). The crude salt was dissolved in a small amount of ethanol, filtered and precipitated with a 25 v/v excess of diethyl ether (yield 42%). Yellow crystals suitable for X-ray investigations were grown from absolute ethanol solution (m.p. 243–245 K).