Crystalline form of phenyl bis (2,4,6-trimethylbenzoyl) phosphine oxide with large particle size and crystallization method for making same

A crystalline form of bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide with large particle size, having:

• an X-ray powder diffraction pattern comprising characteristic peaks at 4.7±0.1, 9.3±0.1, 12.2±0.1, 13.5±0.1, 14.0±0.1, 16.2±0.1, 17.3±0.1, 18.7±0.1, 19.6±0.1, and 24.9±0.1 degrees 2θ;
• wherein, the crystalline form belongs to a triclinic crystal system and to a space group P-1;
• and wherein, the crystalline form is characterized by unit cell parameters substantially equal to the following:
• cell dimensions from single crystal:
• a=8.0301(16)Å
• b=8.6673(17)Å
• c=19.252(4)Å
• α=84.07(3°)
• β=82.83(3°)
• γ=63.75(3°)
• molecules/unit cell (Z):
• 2;
• wherein the crystalline form of bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide is fabricated in accordance with the steps:
• (1) adding a solid of bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide to a solvent and mixing with stirring, followed by heating to 50 to 70° C. to achieve complete dissolution and cooling the solution to room temperature;
• and
• (2) adding an anti-solvent to the solution obtained in the step (1) to cause precipitation of crystals and allowing the crystals to grow at a constant temperature for 10 to 60 minutes, so as to give a slurry containing the crystals, which is subjected to filtration and then drying to obtain a crystal product of bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide.