Thermal expansion of coronene CH at 185-416 K.

The coefficient of the thermal expansion of P2 /a coronene was measured using X-ray diffraction in the temperature range from 185 to 416 K. It increases with increasing temperature from 4.8 × 10 K at 185 K to 4.9 × 10 K at 416 K. At 298 K, α = 1.9 × 10 K. In the temperature interval between 298 and 416 K, the thermal expansion can be described by equation α = −6.66 × 10 + 2.72 × 10 T + 4.62 T. Comparison with previous data indicates that the thermal expansion of PAHs decreases with an increasing amount of benzene rings in their structure. [ABSTRACT FROM AUTHOR]