A cyclic diacetylene (XIa) has been synthesized by the oxidative coupling of 1, 5-bis (propargyloxymethyl) naphthalene (X) with a cyclic dimer (XIb) and a cyclic trimer (XIc). The electronic spectra of XIb and XIc have been found to be almost identical with that of naphthalene with respect to the location of the absorption maxima and the intensities. On the other hand, a marked decrease in the absorption intensities has been observed in the ...
