A residue produced by distillation or heat treatment of coal tar. It is a solid at room temperature, consists of a complex mixture of numerous predominantly aromatic hydrocarbons and heterocyclics, and exhibits a broad softening range instead of a defined melting temperature.
The hydrogen @A00442@ in coal tar @P04677@ (ratio of aromatic to total content of hydrogen atoms) varies from 0.7 to 0.9.
PAC, 1995, 67, 473. 'Recommended terminology for the description of carbon as a solid (IUPAC Recommendations 1995)' on page 485 (https://doi.org/10.1351/pac199567030473)