Crystal structure of 1-methoxypyrene

The title compound, C17H12O, crystallized with three independent molecules (A, B and C) in the asymmetric unit. In the crystal, the three independent molecules are linked by π–π interactions [centroid–centroid distances = 3.551 (3)–3.977 (2) Å], which lead to the formation of trimers. Between the trimers there are a number of C—H⋯π interactions generating a laminar arrangement parallel to (010). The methoxymethyl group in molecule A is disordered over two sets of sites, with an occupancy ratio of 0.56 (9):0.44 (9).


S1. Introduction
π-conjugated aromatic compounds are promising materials for use in opto-electronic devices, particularly for organic photovoltaics (OPVs). These compounds exhibit both energy and charge transfer, and their absorption and emission wavelengths can be tuned (Dössel et al., 2012). Pyrene derivatives have been extensively studied due to their excellent optical and electronic properties for example, excimer/monomer emission. Moreover, pyrene shows a long fluorescence lifetime which reaches 400 ns in cyclohexane solution (Kim et al., 2008). Due to its susceptibility to aromatic substitution at the 1-, 3-, 6-and 8-positions, pyrene is often functionalized at these positions in order to improve its properties. In this context the title compound, 1-methoxypyrene, appears in the literature as an important intermediate in the synthesis of more elaborate compounds. Thus, in this context we report herein on the synthesis and crystal structure of the title compound.

S2.1. Synthesis and crystallization
1-methoxypyrene was synthesized from 1-pyrenol which is synthesized from 1-pyrenecarboxaldehyde that is commercially available (Aldrich). Pyrenol (0.3 g, 1.37 mmol) was added to a solution of KOH (0.23 g, 4.12 mmol) dissolved in DMSO (7 mL). To this solution, methyl iodide (0.25 g, 1.78 mmol) was added and the resulting reaction mixture was stirred for 1 h at room temperature to produce the desired product (Almeida et al., 2009)

S2.2. Refinement
Crystal data, data collection and structure refinement details are summarized in Table 1. The H atoms were included in calculated positions and treated as riding: C-H = 0.93 -0.96 Å with U iso (H) = 1.5U eq (C) for the methyl H atoms and = 1.2U eq (C) for other H atoms. The methoxy methyl group (C17) in molecule A is disordered over two sites with an occupancy ratio of 0.56 (9):0.44 (9).

S3. Results and discussion
The asymmetric unit of the title compound consist of three independent molecules (A, B and C), as shown in Fig. 1. The pyrene moiety shows bond lengths and angles similar to those observed for free pyrene (Camerman & Trotter, 1965) and other pyrene derivatives (Gruber et al., 2006(Gruber et al., , 2010. In the crystal, the three molecules are linked by π-π interactions to give a trimeric motif.  Fig. 2).

Figure 1
The molecular structure of the title compound, with atom labelling. Displacement ellipsoids are drawn at the 35% probability level. The minor component of the disordered methyl group of molecule A is not shown.

Figure 2
A view along the b axis of the crystal packing of the title compound, showing the laminar arrangement as a result of the π-π and C-H···π interactions (dashed lines; see Table 1 for details).  Hydrogen site location: inferred from neighbouring sites H-atom parameters constrained