858.    EYBER, G.  [Photochemical Decomposition of Iron Pentacarbonyl.]  Ztschr. Physik. Chem., vol. 144A, 1929, pp. 1-21; Chem. Abs., vol. 24, 1930, p. 553.

      Eyber has investigated the absorption spectrum of hexane solutions of Fe(CO)5 and finds strong absorption below about 4,600 Ǻ. U.  The decomposition of the vapor by radiation of wave length, 4,000 Ǻ. U. has been studied.  A quantum efficiency of 2 is found.  This is explained by the postulation of the formation of an activated molecule that reacts with a normal molecule to give CO and Fe2(CO)9.  Foreign gases (CO2, A, N2 and CO) inhibit the decomposition; a deactivation of the excited molecule may be the reason.

                                              K1(Iabs.)

d(CO)/dt=  ----------------------------------

                       1+(K3/K2).  [(G)/(C)]

where (G) is foreign gas and (C) is pentacarbonyl, satisfies the data.  O2, if present, alters the reaction.  The vapor-pressure curve from 14 to + 20 has been determined.