Synthesis, crystal structure and optical property of 1,6-bis(p-tolylthio)pyrene, C30H22S2

C30H22S2, triclinic,P1 (no. 2), a= 7.5621(2) Å, b=8.6787(3) Å, c = 9.8951(3) Å, α = 110.4180(10)°, β = 97.6810(10)°, γ = 108.8430(10)°, V = 553.33(3) Å, Z = 1, Rgt(F ) = 0.0413, wRref(F ) = 0.1160, T = 200(2) K.


CCDC no.: 2036234
The molecular structure is shown in the Figure. Table 1 contains crystallographic data and Table 2 contains the list of the atoms including atomic coordinates and displacement parameters.

Source of material
All chemicals were purchased from commercial sources and used as received without further purification. The title compound was prepared by two steps using pyrene as the starting materials. The intermediate 1,6-dibromopyrene was prepared through the bromination of pyrene according to the literature [4]. The title compound was synthesized according to the similar method in the literature [5] and the detailed procedures were displayed as following: Firstly, 3.38 g (24 mmol) of p-methylthiophenol, 3.60 g (10 mmol) of 1,6-dibromopyrene and 80 mL of dimethylformamide (DMF) were added to a 150 mL round bottom flask. The resulting mixture was stirred for 20 min in an ice bath under the protection of nitrogen atmosphere. Secondly, 0.96 g (24 mmol) of NaH (60%) was slowly added to the above flask in batches and the mixture was stirred for 10 min. Then, the mixture was refluxed for 10 h. After the mixture was cooled, light yellow needle-like crystals were obtained directly. Yield: 3.80 g, 86%. The selected suitable single crystal was structurally determined by X-ray diffraction analysis.

Experimental details
All H atoms bound to C atoms were introduced using the HFIX command in the SHELXL-2014 program [2], with the value of 0.93 Å or 0.96 Å for C-H bond distances. All H atoms were allowed for as riding atoms with U iso (H ) = 1.2U eq (C) or U iso (H ) = 1.5U eq (C) for hydrogen Mo Kα radiation (. Å) μ: . mm − Diffractometer, scan mode: Bruker APEX II, φ and ω θ max , completeness: , , . Criterion for I obs , N(hkl) gt : atoms bonded to pyrene ring and methyl group, respectively. The structure was checked using PLATON [3].

Comment
Organic functional molecules with tunable optical, biological and bifunctional as well as mutifunctional properties have gained great deal of attention due to their potential applications in sensors, live-cell imaging, organic solar cells (OSCs), organic light-emitting diodes (OLEDs) and so on [5][6][7][8][9][10][11]. As one of the most well-known functional molecules, pyrene and its derivatives have been widely investigated by many researchers because of their effectively fluorescent emission, facile synthesis and easy functionalization. Up to date, a great number of pyrenebased derivatives using pyrene as the starting material or as the functional precursor have been reported [12][13][14][15][16][17][18]. However, there are relatively few reports about pyrenebased thioether compounds. Organic functional molecules containing sulfur atoms have also attracted extensive research interest because their special electronic structures may result into special properties, which could develop more novel functional material precursors. Very recently, the crystal structures of pyrene-based thioether compounds such as 1,3,6,8-tetrakis(p-tolylthio)pyrene, 1,8-bis(p-tolylthio)pyrene, 1,6-bis(methylthio)pyrene and so on, have been reported by our group using pyrene as the starting material [5,[19][20][21], especially, some of them exhibit relatively excellent fluorescent properties and sensor function for peroxides such as m-chloroperoxybenzoic acid. As a continuation of this work, herein, we report the crystal structure of a new pyrene-based thioether compound which was synthesized in high yield. In addition, the optical property of the title compound was studied preliminarily.
The single X-ray diffraction analysis shows that the crystal structure agrees well with the expected structure of the title compound 1,6-bis(p-tolylthio)pyrene, owing inversion symmetry (see the structure drawing). The pryene core as the main body together with the two side sulfur atoms are almost in a strict plane, whereby the largest deviation for the S1 atom from the main plane is 0.047(3) Å. The thioether bond distances are 1.7725(15) Å for C1-S1 and 1.7729(16) Å for C9-S1, respectively, which are typical C aryl -S bond distances. The C1-S1-C9 bond angle is 103.71°. The bond distances and angles around the sulfur atom in the molecule are comparable to  those of its derivatives 1,8-bis(p-tolylthio)pyrene and 1,3,6,8-tetrakis(p-tolylthio)pyrene [5,19]. The dihedral angle between the pyrene and benzene ring is 81.77(3)°. There exist relatively strong C-H … π interactions between the adjacent pyrenyl unit and the benzene segment, which link the title units into a one-dimensional supramolecular structure (Figure 1). The optical property of the title compound was investigated preliminarily. The title compound 1,6-bis(p-tolylthio) pyrene was dissolved in dichloromethane, the absorption is in the range of 325 to 425 nm and a blue emission with peak around 425 nm for the above solution was observed, which are very similar to those of its derivative of 1,8-bis(p-tolylthio) pyrene [5]. The crystal state of the title compound emits green fluorescence with the main peak at 490 nm. Because of its extremely poor solubility, the further sensor property for peroxides has not been carried out.
Author contribution: All the authors have accepted responsibility for the entire content of this submitted manuscript and approved submission. Research funding: This work was supported by the Doctoral Program (JYJBZX19-04) and the National Postdoctoral fund (2019M652022). Conflict of interest statement: The authors declare no conflicts of interest regarding this article.