ABSTRACT
CASRN: 108-08-7; DOT label: flammable liquid; molecular formula: C7H16; FW: 100.20 Physical state and color: Colorless liquid with an odor resembling heptane. An odor threshold concentration of 940 ppbv was reported by Nagata and Takeuchi (1990). Melting point (°C): -119.2 (Weast, 1986) Boiling point (°C): 80.5 (Weast, 1986) Density (g/cm3): 0.6727 at 20 °C, 0.66832 at 25 °C (quoted, Riddick et al., 1986) Diffusivity in water (x 10-5 cm2/sec): 0.70 at 20 °C using method of Hayduk and Laudie (1974) Dissociation constant, pKa: >14 (Schwarzenbach et al., 1993) Flash point (°C): -12.1 (Hawley, 1981) Heat of fusion (kcal/mol): 1.636 (quoted, Riddick et al., 1986) Henry’s law constant (atm⋅m3/mol): 2.94 at 25 °C (Mackay and Shiu, 1981) Interfacial tension with water (dyn/cm): 50.0 at 25 °C (quoted, Freitas et al., 1997) Soil organic carbon/water partition coefficient, log Koc: Unavailable because experimental methods for estimation of this parameter for aliphatic hydrocarbons are lacking in the documented literature Octanol/water partition coefficient, log Kow: 3.24 using method of Hansch et al. (1968) Solubility in organics: Soluble in acetone, alcohol, benzene, chloroform, and ether (Weast, 1986) Solubility in water (mg/kg): 4.41 at 25 °C (shake flask-GLC, Price, 1976)
4.06 at 25 °C (shake flask-GC, McAuliffe, 1966) 6.50 at 0 °C, 5.50 at 25 °C (shake flask-GC, Polak and Lu, 1973) Vapor density: 4.10 g/L at 25 °C, 3.46 (air = 1) Vapor pressure (mmHg): 98.4 at 25 °C (Wilhoit and Zwolinski, 1971) Environmental fate: Photolytic. Based on a photooxidation rate constant of 5.0 x 10-12 cm3/molecule⋅sec for the reaction of 2,3-dimethypentane and OH radicals in air, the half-life is 27 h (Alltshuller, 1991). Chemical/Physical. Complete combustion in air yields carbon dioxide and water vapor. 2,4Dimethylpentane will not hydrolyze because it has no hydrolyzable functional group. Source: In diesel engine exhaust at a concentration of 0.3% of emitted hydrocarbons (quoted, Verschueren, 1983). Schauer et al. (1999) reported 2,4-dimethylpentane in a diesel-powered medium-duty truck exhaust at an emission rate of 410 µg/km. California Phase II reformulated gasoline contained 2,2-dimethylbutane at a concentration of 15,700 mg/kg. Gas-phase tailpipe emission rates from gasoline-powered automobiles with and without catalytic converters were 2.92 and 354 mg/km, respectively (Schauer et al., 2002). Uses: Organic synthesis; gasoline component.
