in tetrahydrofuran Irradiation (UV/VIS); (Ar) soln. Cr complex and diyne in THF was irradiated with Hg/Xe arc lamp (400-550 W) atb 210-600 nm for 6 h at room temp.; volatiles were removed in vacuo, residue was extd. with hexane, soln. was decanted and stored at -60°C overnight, soln. was filtered and evapd.; elem. anal.;