ABSTRACT
Note: According to Chevron Phillips Company’s (2005) product literature, >99.5 wt % 1,2dimethylcyclohexane (mixed stereoisomers) contains ≤ 300 ppm o-xylene. CASRN: 6876-23-9; 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): -37 (Weast, 1986) Boiling point (°C): 119.3 (Weast, 1986) Density (g/cm3): 0.76255 at 20 °C, 0.75835 at 25 °C (Dreisbach, 1959) 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): ≈ 10 (isomeric mixture, Hawley, 1981) Heat of fusion (kcal/mol): 2.73 (Dreisbach, 1955) 2.491-2.508 (Dean, 1987) Henry’s law constant (atm⋅m3/mol): 0.91 at 25 °C (Mackay and Shiu, 1981) Ionization potential (eV): 10.08 ± 0.03 (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: 3.41 using method of Hansch et al. (1968)
Soluble in acetone, alcohol, benzene, ether, ligroin (Weast, 1986); miscible with cyclohexane and cycloheptane. Solubility in water: 3.84 mg/kg at 25 °C (shake flask-GLC, Price, 1976) In mg/L: 5.10 at 0.00 °C, 4.87 at 5.00 °C, 4.73 at 10.00 °C, 4.66 at 15.00 °C, 4.66 at 20.00 °C,
4.72 at 25.00 °C, 4.83 at 30.00 °C, 5.00 at 35.00 °C, 5.22 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): 22.65 at 25 °C (quoted, Mackay et al., 1982) Environmental fate: Chemical/Physical. Complete combustion in air yields carbon dioxide and water vapor. trans1,2-Dimethylcyclohexane will not hydrolyze because it has no hydrolyzable functional group. Toxicity: EC50 (48-h) for Daphnia pulex 4,867 µg/L (Smith et al., 1988). Source: Component of gasoline (quoted, Verschueren, 1983) Use: Organic synthesis.
