Ultraviolet and Infrared Spectra of Diboron in Solid Neon at 4 K.

Apart from products H, B, BH, BH and BH identified from their emission spectra in the UV/Vis region, photolysis of diborane(6) dispersed in solid neon at 4 K with far-ultraviolet light from a synchrotron led to observation of absorption line (0,0) of the electronic transition A Σ ←X Σ of B at 326.39 nm. Absorption lines (1,0) of B , B B and B were recorded at 316.63, 316.40 and 316.15 nm, respectively. ΔG of state A Σ for B , B B and B in solid neon are accordingly derived to be 945, 968 and 993 cm , respectively. Weak lines (0,1) of B at 29586 cm and of B B at 29560 cm , corresponding to 1042±30 and 1068±30 cm for vibrational modes in the electronic ground state, were recorded in emission. An absorption line recorded at 1066.5±0.5 cm in infrared spectra after photolysis of either B H in Ne or B D with D in Ne is thus attributed to B B.