The alternation of bond lengths in long conjugated molecules. - II. The polyacenes

Abstract

Abstract The infinite polyacene (C4H2)∞ has been studied by methods similar to those previously applied to the infinite polyene. Whereas in the latter the most stable configuration is one in which the C—C bonds are alternately long and short, it is found that in the infinite polyacene the external C—C bonds all have the same length in the most stable configuration, being slightly shorter than the cross bonds. The reasons for this are examined.