1991 Volume 70 Issue 8 Pages 790-801
-Iodine as an electron acceptor interacts with coal molecules producing charge transfer complex. The change of spin concentration of iodine doped coal, Ns reflects the π-π interaction in condensed aromatic rings in coal structure. The value of Ns in-crease with the increase of rank up to 90% of carbon (daf). On the other hand, the value of Ns for TCNQ doped coal increases with decrease of coal rank. Interpretation for the fact above is that TCNQ molecule goes to the sites associating with oxygen containing functional groups, which are able to form hydrogen bonding.
