Molecular Formula: C₁₂H₁₈Zr
Molar mass: 253.49532 g/mol
Boiling Point: 170°C
Melting point: 170 °C (dec.)(lit.)
Storage temp: Below 5° C
Appearance: Pale yellow to yellow crystals or needles
Product categories of Bis(cyclopentadienyl)dimethylzirconium (CAS NO.12636-72-5): Catalysis and Inorganic Chemistry;Zirconium;Chemical Synthesis
Structure of Bis(cyclopentadienyl)dimethylzirconium (CAS NO.12636-72-5):
               
Systematic Name: Cyclopenta-1,3-diene; dimethylzirconium 
SMILES: C[Zr]C.C1C=CC=C1.C1C=CC=C1 
InChI: InChI=1/2C5H6.2CH3.Zr/c2*1-2-4-5-3-1;;;/h2*1-4H,5H2;2*1H3;/r2C5H6.C2H6Zr/c2*1-2-4-5-3-1;1-3-2/h2*1-4H,5H2;1-2H3 
InChIKey: UZYVUILMWYIKNS-QBSKBRLBAA 
Std. InChI: InChI=1S/2C5H6.2CH3.Zr/c2*1-2-4-5-3-1;;;/h2*1-4H,5H2;2*1H3; 
Std. InChIKey: UZYVUILMWYIKNS-UHFFFAOYSA-N

Carcinogenicity of Bis(cyclopentadienyl)dimethylzirconium (CAS NO.12636-72-5) hasn't been listed as a carcinogen by NTP, IARC,ACGIH, or CA Prop 65. And its toxicological properties have not been fully investigated.

Hazard Codes: Xi
Risk Statements:
36:  Irritating to the eyes
37:  Irritating to the respiratory system
38:  Irritating to the skin
Safety Statements:
26:  In case of contact with eyes, rinse immediately with plenty of water and seek medical advice
37:  Wear suitable gloves
39:  Wear eye/face protection

 Bis(cyclopentadienyl)dimethylzirconium ,its cas register number is 12636-72-5.It also can be called Cyclopenta-1,3-dien-dimethylzirconium(2:1) and 1,3-Cyclopentadiene, compd. with dimethylzirconium (2:1) .It 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 shoesmedical 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.Give artificial respiration while not breathing. When breathing is difficult, give oxygen. 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.Notes to physician: Treat supportively and symptomatically.
In addition, Bis(cyclopentadienyl)dimethylzirconium (CAS NO.12636-72-5) is moisture sensitive with air.It is not compatible with strong oxidizing agents, and you must not take it with incompatible materials and not be exposured to moist air or water.And also prevent it to broken down into hazardous decomposition products: carbon dioxide, carbon monoxide.