Preparation and characterization of single crystals of tetrakis(4-(5,5-dimethyl-2-phenyl-1,3-dioxan-2-yl)phenyl)germane
Graphical abstract
Section snippets
Preparation of 2-(4-bromophenyl)-5,5-dimethyl-2-phenyl-1,3-dioxane (1)
4-Bromobenzophenone (20.0 g, 76.6 mmol), 2,2-dimethylpropane-1,3-diol (12.0 g, 115.0 mmol), 4-methylbenzenesulfonic acid (0.66 g, 3.84 mmol) was dissolved in toluene (600 ml), and the mixture was heated at reflux for 19 h. The resulting mixture was cooled to room temperature and diluted with CHCl3. The organic layer was washed with Na2CO3 solution, water and brine, dried over anhydrous MgSO4, filtered, and concentrated in vacuo. The resulting crude product was recrystallized from iso-propanol,
Preparation and crystallization of tetrakis(4-(5,5-dimethyl-2-phenyl-1,3-dioxan-2-yl)phenyl)germane (2)
2-(4-Bromophenyl)-5,5-dimethyl-2-phenyl-1,3-dioxane, 1 (15.4 g, 44 mmol) was pre-dried by Ar purging and dissolved in THF (250 mL). To that solution, n-BuLi (17.6 mL, 44 mmol, 2.5 M in hexane) was added dropwise under stirring at −78 °C in Ar atmosphere. After 30 min of stirring, GeCl4 (1.00 mL, 8.74 mmol) was added to the solution at −78 °C. The reaction mixture was stirred for 3 h at −78 °C and 12 h at ambient temperature. The resulting mixture was cooled to room temperature and diluted with CHCl3. The
Single-crystal X-ray diffraction
The structure of 2 was determined by the standard crystallographic method, using a colorless plate crystal (0.028 × 0.034 × 0.046 mm3) of 2 for single crystal data analysis. All the data were collected using a Bruker SMART BREEZE diffractometer equipped with a 1 K CCD area detector using graphite monochromated Mo Kα radiation at 200 K. A hemisphere of data was collected using a narrow-frame method with the scan widths of 0.30° in omega and an exposure time of 5 s/frame. The first 50 frames were
Powder X-ray diffraction
Powder X-ray diffraction was used to confirm the phase purity of the synthesized material. Powder XRD pattern was collected at room temperature using a Bruker D8-Advance diffractometer equipped with Cu Kα radiation at 40 kV and 40 mA. The well ground polycrystalline sample of 2 was mounted on a sample holder and scanned in the 2θ range 5–70° with a step size and step time of 0.02° and 0.2 s, respectively. The experimental powder XRD pattern is in good agreement with the calculated data from the
Second-order nonlinear optical measurements
Powder second-harmonic generating (SHG) measurements of polycrystalline material 2 were performed using a modified Kurtz-NLO system using 1064 nm radiation [26]. A DAWA Q-switched Nd:YAG laser, operating at 20 Hz, was used for the measurements. Because the SHG efficiency has been shown to depend strongly on the particle size, polycrystalline samples were ground and sieved (Newark Wire Cloth Co.) into distinct particle size ranges (20–45, 45–63, 63–75, 75–90, 90–125, 125–150, 150–200, 200–250, >
Acknowledgments
This research was supported by the Chung-Ang University Graduate Research Scholarship in 2017 and Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education [2017R1D1A1B03031915].
References (27)
- et al.
Org. Electron.
(2009) - et al.
RCS Adv.
(2015) - et al.
RCS Adv.
(2015) Mater. Chem.
(2005)- et al.
J. Am. Chem. Soc.
(2000) - et al.
J. Mater. Chem.
(2007) - et al.
J. Mater. Chem.
(2008) - et al.
Chem. Rev.
(2007) - et al.
J. Am. Chem. Soc.
(2003) - et al.
Adv. Funct. Mater.
(2009)