Ring signatures for benzenoids with up to seven rings, part 2: Pericondensed systems

An array of integers p(ij) indicate in how many of the K resonance structures one finds 6 > i > 0 pi-electrons in the corresponding ring (which is labeled with capital letters A through a subsequent letter up to G). The index j for the rows indicates the ring type, denoted by capital letters (that is, j = 1 stands for A, j = 2 stands for B, etc.). Row sums lead to pi-electron ring partitions after division by the number K of resonance structures. Column sums lead to a sequence of seven integers (R-i sequence) which after division by K affords the r(i) sequence; this is finally converted into the signature of the benzenoid s(i) sequence). The analysis of signatures for pericondensed benzenoids with h = 4 through 7 benzenoid rings has revealed interesting regularities and correlations with structure, and has also allowed a confirmation of Clar's theory by investigating five isomeric dibenzopyrenes. (c) 2008 Wiley Periodicals, Inc.