ABSTRACT
CH3 Note: According to Chevron Phillips Company’s (2005) Technical Data Sheet, 99.5-99.7 wt % isobutylbenzene contains n-butylbenzene (0.1-0.2 wt %) and toluene (≤ 0.2 wt %). CASRN: 538-93-2; DOT: 1993; molecular formula: C10H14; FW: 134.22; RTECS: DA3550000; Merck Index: 12, 5149 Physical state, color, and odor: Clear, colorless, liquid with an odor resembling butylbenzene, tert-butylbenzene, ethylbenzene, or toluene. An odor threshold concentration of 80 µg/kg was reported (quoted, Verschueren, 1983) Melting point (°C): -51.5 (Weast, 1986) Boiling point (°C): 170.5 (Windholz et al., 1983) Density (g/cm3 at 20 °C): 0.8532 (Weast, 1986) 0.8673 (Windholz et al., 1983) Diffusivity in water (x 10-5 cm2/sec): 0.68 at 20 °C using method of Hayduk and Laudie (1974) Dissociation constant, pKa: >14 (Schwarzenbach et al., 1993) Flash point (°C): 55 (Aldrich, 1990) Lower explosive limit (%): 0.8 (NFPA, 1984) Upper explosive limit (%): 6.0 (NFPA, 1984) Henry’s law constant (x 10-2 atm⋅m3/mol): 1.09 at 25 °C (Hine and Mookerjee, 1975) Ionization potential (eV): 8.68 (Lias, 1998) Soil organic carbon/water partition coefficient, log Koc: 3.90 using method of Karickhoff et al. (1979)
ow 4.11 (shake flask-GC, Chiou et al., 1982) Solubility in organics: Soluble in acetone, alcohol, benzene, ether, and petroleum hydrocarbons (Weast, 1986) Solubility in water: 10.1 mg/kg at 25 °C (shake flask-GLC, Price, 1976) 33.71 mg/L at 25 °C (shake flask-GC, Chiou et al., 1982) 70.2 µmol/L in 0.5 M NaCl at 25 °C (Wasik et al., 1984) Vapor density: 5.49 g/L at 25 °C, 4.63 (air = 1) Vapor pressure (mmHg): 2.06 at 25 °C (quoted, Mackay et al., 1982) Environmental fate: Biological. Oxidation of isobutylbenzene by Pseudomonas desmolytica S44B1 and Pseudomonas convexa S107B1 yielded 3-isobutylcatechol and (+)-2-hydroxy-8-methyl-6-oxononanoic acid (Jigami et al., 1975). Chemical/Physical. Complete combustion in air yields carbon dioxide and water vapor. Isobutylbenzene will not hydrolyze because it has no hydrolyzable functional group. Uses: Perfume synthesis; flavoring; pharmaceutical intermediate.
