9-(4-Methylphenoxycarbonyl)-10-methylacridinium trifluoromethanesulfonate

In the crystal structure of the title compound, C22H18NO2 +·CF3SO3 −, adjacent cations are linked through C—H⋯π and π–π interactions, and 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 3.0 (1)°. The carboxyl group is twisted at an angle of 83.1 (1)° relative to the acridine skeleton. The mean planes of adjacent acridine units are parallel or inclined at an angle of 75.2 (1)° in the crystal structure.

In the crystal structure of the title compound, C 22 H 18 NO 2 + Á-CF 3 SO 3 À , adjacent cations are linked through C-HÁ Á Á and interactions, and the cations and anions are connected by C-HÁ Á ÁO and C-FÁ Á Á interactions. The acridine and benzene ring systems are oriented at a dihedral angle of 3.0 (1) . The carboxyl group is twisted at an angle of 83.1 (1) relative to the acridine skeleton. The mean planes of adjacent acridine units are parallel or inclined at an angle of 75.2 (1) in the crystal structure.
Cg3 and Cg4 are the centroids of the C5-C8/C13/C14 and C18-C23 rings, respectively. CgIÁ Á ÁCgJ 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.

Comment
9-(Phenoxycarbonyl)-10-methylacridinium salts appear to be convenient chemiluminescent indicators or the chemiluminogenic fragments of chemiluminescent labels (Zomer & Jacquemijns, 2001), which are widely 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). Oxidation of the cations of these salts with hydrogen peroxide in alkaline media is accompanied by the removal of the phenoxycarbonyl fragment and the conversion of the remaining part of the molecule to electronically excited, light emitting 10-methyl-9-acridinone (Rak et al., 1999;Zomer & Jacquemijns, 2001). The efficiency of chemiluminescence -crucial for analytical applications -is affected by the constitution of the phenyl fragment (Zomer & Jacquemijns, 2001).
This prompted us to undertake investigations on derivatives substituted in this fragment. Here we present the structure of 9-(4-methylphenoxy)carbonyl-10-methylacridinium trifluoromethanesulfonate, a structural isomer of the 2-methyl substituted salt, whose structure has already been refined (Sikorski et al., 2006).

Special details
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.  Symmetry code: (i) -x + 3/2, y + 1/2, -z + 1/2. Notes: Cg1 and Cg2 are the centroids of the C9/N10/C11-C14 and C1-C4/C11/C12 rings, respectively.  (17) 3.565 (2) 1.613 (2) Symmetry code: (v) -x + 1, -y, -z + 1. Notes: Cg3 and Cg4 are the centroids of the C5-C8/C13/C14 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 is the perpendicular distance of CgI from ring J. CgI_Offset is the distance between CgI and perpendicular projection of CgJ on ring I.