Polyynes: Synthesis with the Submerged Electric Arc - Polyynes: Synthesis, Properties, and Applications - page 162

FIGURE 8.7 From top to bottom: the elctronic absorption spectra of polyynes with

n ¼ 4, 5, 6, 7, and 8. The assignment is unequivocal (see Table 8.1 ). These spectra

were recorded by the diode-array detector of the HPLC system on each peak shown

in Figure 8.6(A) .

electric arc between graphite electrodes. As reported in the experimental
section, we have used Ilosvay's reagent to make this assay. Ilosvay's reagent
is simply a solution of CuI in aqueous ammonia in the presence of hydro-
xylamine. This reagent is of great importance both for the preparation of
copper acetylides from terminal acetylenes (R R 0 ¼ ¼ Cu) and also to test the

presence of -C C-H group in a given molecule. When polyynes solutions in