ABSTRACT
Note: According to Chevron Phillips Company’s (2005) product literature, >99.5 wt % 1,2dimethylcyclohexane (mixed stereoisomers) contains o-xylene at a maximum concentration of 300 ppm. CASRN: 2207-01-4; DOT: 2263; DOT label: flammable liquid; molecular formula: C8H16; FW: 112.22 Physical state and color: Clear, colorless, flammable liquid with a mild characteristic odor. Melting point (°C): -50.1 (Weast, 1986) Boiling point (°C): 129.7 (Weast, 1986) Density (g/cm3): 0.79627 at 20 °C, 0.79222 at 25 °C (quoted, Riddick et al., 1986) Diffusivity in water (x 10-5 cm2/sec): 0.72 at 20 °C using method of Hayduk and Laudie (1974) Dissociation constant, pKa: >14 (Schwarzenbach et al., 1993) Flash point (°C): -12 (Aldrich, 1990) Heat of fusion (kcal/mol): 0.3932 (quoted, Riddick et al., 1986) Henry’s law constant (atm⋅m3/mol): 0.354 at 25 °C (Hine and Mookerjee, 1975) Ionization potential (eV): 10.08 ± 0.02 (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: 3.26 using method of Hansch et al. (1968)
Soluble in acetone, alcohol, benzene, ether, ligroin (Weast, 1986); miscible with cyclohexane and cycloheptane. Solubility in water: 6.0 mg/kg at 25 °C (shake flask-GC, McAuliffe, 1966) In mg/L: 6.59 at 0.00 °C, 6.27 at 5.00 °C, 6.05 at 10.00 °C, 5.93 at 15.00 °C, 5.90 at 20.00 °C,
5.94 at 25.00 °C, 6.06 at 30.00 °C, 6.25 at 35.00 °C, 6.51 at 40.00 °C (dynamic saturation column method-GC, Dohányosová et al., 2004)
Vapor density: 4.59 g/L at 25 °C, 3.87 (air = 1) Vapor pressure (mmHg): 14.5 at 25 °C (Wilhoit and Zwolinski, 1971) Environmental fate: Chemical/Physical. Complete combustion in air yields carbon dioxide and water vapor. cis-1,2Dimethylcyclohexane will not hydrolyze because it has no hydrolyzable functional group. Toxicity: EC50 (48-h) for Daphnia pulex 3,235 µg/L (Smith et al., 1988). Source: Component of gasoline (quoted, Verschueren, 1983) Use: Organic synthesis.
