PHOTOABSORPTION SPECTRA OF SI(CH3O)4, SI(CH3O)2(C6H5)2,SI(C2H5O)4,TI(I-C3H7O), AND BCL3 IN THE REGION OF 6-9.6 EV

The total photoabsorption cross sections (sigma(t)) of gaseous Si(RO)4 (RO=CH3O and C2H5O), Si(CH3O)2(C6H5)2: Ti(i-C3H7O)4, and BCl3 have be en measured in the region of hv=6-9.6 eV. In the compounds containing alkoxy groups, the photoabsorption bands observed around 6.9 eV and 7. 7-8.5 eV are tentatively assigned as the 3s and 3p Rydberg excitations of the non-bonding electron of an oxygen atom (n(o)), respectively. T he sigma(t) values for 3p-->n(o) Rydberg lie in the region of 40-50 Mb . The photoabsorption bands of BCl3 observed at 7.1, 8.35, and 9.1 eV, in which the peak at 7.1 eV has a large at 300 Mb, are assigned as th e pi valence shell, 4s, and 4p Rydberg transitions of the outermost l one pair electron of a chlorine atom, respectively.