ABSTRACT
CYCLOPENTADIENE Synonyms: Cyclopenta-1,3-diene; 1,3-Cyclopentadiene; EINECS 208-835-4; Pentole; R-pentine; Pyropentylene.
CASRN: 542-92-7; molecular formula: C5H6; FW: 66.10; RTECS: GY1000000; Merck Index: 12, 2807 Physical state, color, and odor: Colorless liquid with a turpentine-like odor. Odor threshold concentration is 1.9 ppm (quoted, Amoore and Hautala, 1983). Melting point (°C): -97.2 (Weast, 1986) -85 (Windholz et al., 1983) Boiling point (°C): 40.0 (Weast, 1986) 41.5-42 (Windholz et al., 1983) Density (g/cm3): 0.804 at 20 °C (Judersleben, 1977) 0.7966 at 25 °C (Windholz et al., 1983) Diffusivity in water (x 10-5 cm2/sec): 0.99 at 20 °C using method of Hayduk and Laudie (1974) Dissociation constant, pKa: 16.0 (Streitwieser and Nebenzahl, 1976) Flash point (°C): 25.0 (open cup, NIOSH, 1997) Henry’s law constant (x 10-2 atm⋅m3/mol): 5.1 at 25 °C (approximate - calculated from water solubility and vapor pressure) Ionization potential (eV): 8.56 (NIOSH, 1997) 8.97 (Franklin et al., 1969) Soil organic carbon/water partition coefficient, log Koc: Unavailable because experimental methods for estimation of this parameter for alicyclic hydrocarbons are lacking in the documented literature Octanol/water partition coefficient, log Kow: 2.34 using method of Hansch et al. (1968) Solubility in organics: Miscible with acetone, benzene, carbon tetrachloride, and ether. Soluble in acetic acid, aniline, and carbon disulfide (Windholz et al., 1983).
