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.
Note:
The hydrogen
aromaticity in coal tar
pitch (ratio of aromatic to total content of hydrogen atoms) varies from 0.7 to 0.9.
Source:
PAC, 1995, 67, 473
(Recommended terminology for the description of carbon as a solid (IUPAC Recommendations
1995))
on page 485
Cite as:
IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by
A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997).
XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic,
J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8.
https://doi.org/10.1351/goldbook.
