Excitons in polymerized diacetylenes

A simple exciton theory for the excited electronic states of poly-2,4-hexadiyn-1,6-diol bis(p-toluene sulphonate) is described. Configuration interaction between bond excitons, charge transfer excitons and two-exciton states is included in the theory. The κ{script} = 0 levels are described and their parentage traced to levels in two model compounds, vinyl acetylene and cyclododecatrienetriyne. The 2 eV transition of the polymer is predicted to be a collective state of the bond and charge transfer excitons with no two-exciton component. The lowest triplet state is predicted to lie below the first singlet and to also have extensive charge transfer character. © 1977.