IUPAC Name: 2,3,4,5-Tetraphenylcyclopenta-2,4-dien-1-one 
Following is the structure of 2,4-Cyclopentadien-1-one,2,3,4,5-tetraphenyl- (CAS NO.479-33-4):
                       
Empirical Formula: C₂₉H₂₀O
Molecular Weight: 384.4685 g/mol
EINECS: 207-530-3
Index of Refraction: 1.673
Molar Refractivity: 120.15 cm³
Molar Volume: 320.5 cm³
Density: 1.199 g/cm³
Flash Point: 269 °C
Melting point: 217-220 °C(lit.)
Surface Tension: 52.1 dyne/cm
Enthalpy of Vaporization: 91.52 kJ/mol
Boiling Point: 617.1 °C at 760 mmHg
Vapour Pressure: 3.68E-15 mmHg at 25 °C
Product Categories: C15 to C38; Carbonyl Compounds;Ketones
Stability of 2,4-Cyclopentadien-1-one,2,3,4,5-tetraphenyl- (CAS NO.479-33-4): Stable. Combustible. Light sensitive
Appearance of 2,4-Cyclopentadien-1-one,2,3,4,5-tetraphenyl- (CAS NO.479-33-4): crystalline purple solid
Canonical SMILES: C1=CC=C(C=C1)C2=C(C(=O)C(=C2C3=CC=CC=C3)C4=CC=CC=C4)C5=CC=CC=C5
InChI: InChI=1S/C29H20O/c30-29-27(23-17-9-3-10-18-23)25(21-13-5-1-6-14-21)26(22-15-7-2-8-16-22)28(29)24-19-11-4-12-20-24/h1-20H
InChIKey: PLGPSDNOLCVGSS-UHFFFAOYSA-N

 2,4-Cyclopentadien-1-one,2,3,4,5-tetraphenyl- (CAS NO.479-33-4) hasn't been listed as a carcinogen by ACGIH, IARC, NTP, or CA Prop 65. And the toxicological properties have not been fully investigated.

Safety Statements: 24/25-22 
S24/25:Avoid contact with skin and eyes. 
S22:Do not breathe dust.
WGK Germany: 3

 2,4-Cyclopentadien-1-one,2,3,4,5-tetraphenyl- , its cas register number is 479-33-4. It also can be called 2,3,4,5-Tetraphenyl-2,4-cyclopentadienone ; 2,3,4,5-Tetraphenylcyclopentadienone ; Cyclone ; Tetracyclon ; Tetracyclone ; Tetraphenyl-2,4-cyclopentadien-1-one ; and Tetraphenylcyclopentadienone .
 2,4-Cyclopentadien-1-one,2,3,4,5-tetraphenyl- (CAS NO.479-33-4) is hazardous, so the first aid measures and others should be known. Such as: When on the skin: first, should flush skin with plenty of water immediately for at least 15 minutes while removing contaminated clothing. Secondly, get medical aid. Or in the eyes: Flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. Then get medical aid soon. While, it's inhaled: Remove from exposure and move to fresh air immediately. And as soon as to get medical aid. Then you have the ingesting of the product : Wash mouth out with water, and get medical aid immediately.
 2,4-Cyclopentadien-1-one,2,3,4,5-tetraphenyl- (CAS NO.479-33-4) could be stable under normal temperatures and pressures. However, it is light sensitive. It also should avoid the condition like incompatible materials, light. It is not compatible with strong oxidizing agents, , strong acids. And also prevent it to broken down into hazardous decomposition products: carbon monoxide, carbon dioxide. However, its hazardous polymerization will not occur. In addition, it should be stored in a cool, dry place, or stored in a tightly closed container.