GERMANE PHOTOCHEMISTRY - PHOTOLYSIS OF GAS-MIXTURES OF PLANETARY INTEREST

Photolysis of germane (GeH4) in the presence of acetylene (C2H2), prop yne (C3H4) or phosphine (PH3) with a 185 nm mercury lamp has been stud ied. The volatile products formed in these reactions are characterized by H-1, P-31 and C-13 NMR. Vinylgermanes are the first reaction produ cts formed in the photolysis of GeH4 with alkynes. A reaction pathway is proposed. The initial step is the dissociation of germane 1 to hydr ogen and GeH3 radicals. Addition of the germyl radical on alkyne is pr oposed as the next step. Vinylgermanes are then formed by radical comb ination. Photolysis of ethenylgermane 2 gives diethenylgermane 3 in th e presence of acetylene and digermaethane 4 in the presence of GeH4. T he application of these findings to Jovian and Saturn atmospheric chem istry is discussed.