New methods have been developed for the selective introduction of fluorine into benzenoid aromatic compounds involving the cleavage of aryl-metal bonds by various ‘electrophilic’ fluorinating agents. Cleavage of aryl-metal bonds has been achieved using trifluoromethyl hypofluorite (CF(_3)OF), caesium fluoroxysulphate (CsSO(_4)F) and elemental fluorine and, by the nature of the process, is regiospecific. Attempts have been made to extend this method to the introduction of fluorine into imidazole bases with some success. This approach has involved the synthesis of trialkylstannyl derivatives of several benzene derivatives and trimethylstannyl derivatives of 1,2-dimethylimidazole and N-methylimidazole. Prior to our attempts at selective introduction of fluorine into the sugar ring of 5-amino-l-(β-D-ribofuranosyl) imidazole-4-carboxamide (AICAR) a series of protection and selective deprotection reactions on the nucleoside were carried out and trifluoromethane sulphonate ester derivatives of the protected nucleoside were synthesized. Fluoride ion displacement of the trifluoromethane sulphonate group to give a fluorosugar has been attempted.

A benzenoid is a molecule that can be represented as a graph. This graph is a fragment of the hexagon lattice. A dominating set $D$ in a graph $G$ is a set of vertices such that each vertex of the graph is either in $D$ or adjacent to a vertex in $D$. The domination number $\gamma=\gamma(G)$ of a graph $G$ is the size of a minimum dominating set. We will find formulas and bounds for the domination number of various special benzenoids, namely, linear chains $L(h)$, triangulenes $T_k$, and parallelogram benzenoids $B_{p,q}$. The domination ratio of a graph $G$ is $\frac{\gamma(G)}{n(G)}$, where $n(G)$ is the number of vertices of $G$. We will use the preceding results to prove that the domination ratio is no more than $\frac{1}{3}$ for the considered benzenoids. We conjecture that is true for all benzenoids.