byproducts: H2, B5H9; other Radiation; 30 min; monochromatic (973.29 1/cm) IR radiation (6.5 +/- 0.5 W) of CO2 laser; partial pressures: 100-300 Torr (B2H6) and 100-700 Torr (H2S); condensation at -50°C; purifn. by fractionated condensation;