9-(Methyl­sulfan­yl)acridinium trifluoro­methane­sulfonate

Beata Zadykowicz; Damian Trzybiński; Artur Sikorski; Jerzy Błażejowski

doi:10.1107/S1600536809004978

. 2009 Feb 21;65(Pt 3):o566–o567. doi: 10.1107/S1600536809004978

9-(Methylsulfanyl)acridinium trifluoromethanesulfonate

Beata Zadykowicz ^a, Damian Trzybiński ^a, Artur Sikorski ^a, Jerzy Błażejowski ^a,^*

PMCID: PMC2968655 PMID: 21582222

Abstract

In the crystal structure of the title compound, C₁₄H₁₂NS⁺·CF₃SO₃ ⁻, N—H⋯O hydrogen bonds link cations and anions into ion pairs. Inversely oriented ion pairs form stacks through multidirectional π–π interactions among the acridine units. The crystal structure features a network of C—H⋯O interactions among stacks and also long-range electrostatic interactions among ions. In the packing of the molecules, the acridine units are nearly parallel in stacks or inclined at an angle of 33.07 (2)° in the four adjacent stacks with which they interact via weak C—H⋯O interactions. The methylsulfanyl group is twisted through an angle of 60.53 (2)° with respect to the acridine ring.

Related literature

For general background, see: Wróblewska et al. (2004 ▶); Zomer & Jacquemijns (2001 ▶). For related structures, see: Meszko et al. (2002 ▶); Mrozek et al. (2002 ▶); Storoniak et al. (2000 ▶). For molecular interactions, see: Aakeröy et al. (1992 ▶); Bianchi et al. (2004 ▶); Hunter et al. (2001 ▶); Spek (2009 ▶); Steiner (1991 ▶). For the synthesis, see: Berny et al. (1992 ▶); Sato (1996 ▶).

Experimental

Crystal data

C₁₄H₁₂NS⁺·CF₃SO₃ ⁻
M _r = 375.40
Monoclinic,
a = 7.2992 (2) Å
b = 17.3090 (6) Å
c = 13.0582 (4) Å
β = 103.910 (3)°
V = 1601.42 (9) Å³
Z = 4
Mo Kα radiation
μ = 0.38 mm⁻¹
T = 295 K
0.45 × 0.40 × 0.20 mm

Data collection

Oxford Diffraction Gemini R Ultra Ruby CCD diffractometer
Absorption correction: none
13308 measured reflections
2841 independent reflections
1944 reflections with I > 2σ(I)
R _int = 0.028

Refinement

R[F ² > 2σ(F ²)] = 0.050
wR(F ²) = 0.161
S = 1.06
2841 reflections
226 parameters
1 restraint
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.51 e Å⁻³
Δρ_min = −0.35 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: ORTEPII (Johnson, 1976 ▶); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809004978/ng2540sup1.cif

e-65-0o566-sup1.cif^{(18.3KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809004978/ng2540Isup2.hkl

e-65-0o566-Isup2.hkl^{(139.5KB, 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
C7—H7⋯O18ⁱ	0.99 (4)	2.38 (4)	3.315 (5)	158 (3)
N10—H10⋯O19	0.86 (2)	1.86 (2)	2.712 (4)	172 (3)

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Symmetry code: (i) Inline graphic .

Table 2. π–π Interactions (Å,°).

Cg_i	Cg_j	Cg⋯Cg	Dihedral angle	Interplanar distance	Offset
Cg1	Cg1ⁱⁱ	3.827 (2)	0.0	3.468 (2)	1.618 (2)
Cg1	Cg3ⁱⁱ	3.634 (2)	1.4	3.474 (2)	1.066 (2)
Cg1	Cg3ⁱⁱⁱ	3.810 (2)	1.4	3.412 (2)	1.695 (2)
Cg2	Cg3ⁱⁱ	3.830 (2)	4.0	3.492 (2)	1.573 (2)
Cg3	Cg1ⁱⁱ	3.634 (2)	1.4	3.483 (2)	1.037 (2)
Cg3	Cg1ⁱⁱⁱ	3.810 (2)	1.4	3.386 (2)	1.747 (2)
Cg3	Cg2ⁱⁱ	3.830 (2)	4.0	3.449 (2)	1.665 (2)

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Symmetry codes: (ii) Inline graphic ; (iii) . Notes: Cg1, Cg2 and Cg3 are the centroids of the C9/N10/C11–C14, C1–C4/C11/C12 and C5–C8/C13/C14 rings, respectively. Cg⋯Cg is the distance between ring centroids. The dihedral angle is that between the planes of rings Cg_i and Cg_j. The interplanar distance is the perpendicular distance of Cg_i from ring j. The offset is the perpendicular distance of ring i from ring j.

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. BZ expresses her gratitude for the fellowship from the European Social Fund, the Polish State Budget and the Budget of the Province of Pomerania within the framework of the Priority VIII Human Capital Operational Programme, action 8.2, subaction 8.2.2 ‘Regional Innovation Strategy’, of the ‘InnoDoktorant’ project of the Province of Pomerania – fellowships for PhD students, 1^st edition.

supplementary crystallographic information

Comment

Acridinium cations containing various substituents at position 9 and alkyl substitutes at the endocyclic N atom (position 10) are susceptible to oxidation by H₂O₂ or other oxidants in alkaline media, leading to the formation of electronically excited 10-alkyl-9-acridinones capable of emitting light with a quantum yield of several percent (Zomer & Jacquemijns, 2001; Wróblewska et al., 2004). The chemiluminescence phenomenon described above is governed by the features of the substituent at position 9. In the search for derivatives that could exhibit enhanced chemiluminescence, we turned our attention to compounds in which the C atom at position 9 is bound to the S atom. The simplest compound that we were able to synthesize was 9-(methylthio)acridinium trifluoromethanesulfonate. It was obtained by the reaction of 9-thioacridinone (Berny et al., 1992) with methyl trifluoromethanesulfonate, which usually leads to quarternarization of the endocyclic N atom (Sato, 1996). The cation of the reaction product has a protonated endocyclic N atom, enabling it to react with oxidants, thereby facilitating the investigation of chemiluminescence phenomena. This paper presents the crystal structure of the title compound. This is, to our knowledge, only the second report on the crystal structure of an acridine derivatives S-substitued at position 9 (for the first one, see Mrozek et al., 2002).

In the cations of the title compound (Fig. 1), the bond lenghts and angles characterizing the geometry of the acridine skeleton are typical of acridine-based derivatives (Storoniak et al., 2000; Meszko et al., 2002; Mrozek et al., 2002). The C9–S15 and S15–C16 bond lengths (1.754 (3) Å and 1.807 (4) Å, respectively) correlate well with those reported for 9-(thio-2'-methyl-4'-nitrophenyl)acridine (Mrozek et al., 2002). The C9–S15–C16 fragment and the acridine ring system, with an average deviation from planarity of 0.037 (4) Å, are oriented at 60.53 (2)° to each other. The acridine units in the lattice are either parallel (within stacks) or inclined at an angle of 33.07 (2)° (in four adjacent stacks with which they interact via C–H···O hydrogen bonds).

In the crystal structure, N–H···O hydrogen bonds (Aakeröy et al., 1992) link cations and anions in ion pairs (Table 1, Fig. 1). Inversely oriented ion pairs form stacks in which the central ring (Cg1) and the aromatic rings (Cg2 and Cg3) are involved in multidirectional π-π interactions (Table 2, Fig. 2) of an attractive nature (Hunter et al., 2001). The crystal structure is stabilized by a network of C–H···O hydrogen type bonding interactions (Steiner, 1991; Bianchi et al., 2004) between neighbouring stacks (Figs 2 and 3) as well as by long-range electrostatic interactions between ions.

Experimental

9-(Methylthio)acridinium trifluoromethanesulfonate was synthesized in two steps. First, 9-thioacridinone was synthesized by heating with stirring a mixture of 9(10H)-acridinone, tetraphosphorus decasulfide and freshly distilled pyridine at 100°C for 1 h (Berny et al., 1992). The reactant mixture was subsequently poured into 30% aq ammonia and the resulting precipitate of 9-thioacridinone filtered off. This compound was then treated with a fivefold molar excess of methyl triluoromethanesulfonate dissolved in dichloromethane for 3 h (Ar athmosphere, room temperature) (Sato, 1996). The crude 9-(methylthio)acridinium trifluoromethanesulfonate thus formed was dissolved in a small amount of ethanol, filtered, and again precipitated with a 25 v/v excess of diethyl ether (yield: 87%). Yellow crystals suitable for X-ray investigations were grown from absolute ethanol solution (m.p. 421–423 K).