THIN-LAYERS OBTAINED BY PHOTOLYSIS OF 4,4'-DIAZIDODIPHENYL IN SOLUTION

It was observed that a solid layer precipitates on the fused silica wi ndow of the cell where 4,4'-diazidodiphenyl is irradiated in solution. The precipitate seems to be a branched and crosslinked polymer contai ning mainly ate, hydrazo and azepine units. The highest amount of azod iphenyl units was obtained in chloroform and the lowest in tetrahydrof uran. As a rule the layer surface was uneven, with scaly aspect. The l ayer seems to be composed of a thin continuous pm on which adhered agg regates whose dimensions and density increase with radiation dose and content of azo units and decrease with solution temperature. The ratio of photocurrent to dark current was found to be in the range 2-30 if mercury discharge radiation of about 100W/m(2) irradiance was used. (C ) 1998 John Wiley & Sons, Ltd.