Benzenoid isomers with extremal Kekulé structure counts: symmetric di-fibonaceno-annelated derivatives

In families of benzenoid isomers, the molecules with maximum (minimum) Kekulé structure counts possess maximum (minimum) stability and other distinguishable properties. These extremal isomers are determined in the case of symmetric di-fibonaceno-annelated benzenoid species B(m,n), obtained from a benzenoid system B by attaching to its two symmetric sites fibonacene fragments of length m and n, where m + n = constant.