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

• Published in: Chemphyschem 2017-01, Vol.18 (1), p.124-127
• Main Authors: Lo, Jen‐Iu, Chou, Sheng‐Lung, Lu, Hsiao‐Chi, Peng, Yu‐Chain, Lin, Meng‐Yeh, Cheng, Bing‐Ming, Ogilvie, J. F.
• Format: Article
• Language: English
• Subjects: diborane; diboron; far-ultraviolet photolysis; IR spectroscopy; Ultraviolet radiation; UV/Vis spectroscopy
• ISSN: 1439-4235; 1439-7641
• DOI: 10.1002/cphc.201601001

Apart from products H, B, BH, BH2 and BH3 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 3Σu−←X 3Σg− of B2 at 326.39 nm. Absorption lines (1,0) of 11B2, 11B10B and 10B2 were recorded at 316.63, 316.40 and 316.15 nm, respectively. ΔG1/2 of state A 3Σu− for 11B2, 11B10B and 10B2 in solid neon are accordingly derived to be 945, 968 and 993 cm−1, respectively. Weak lines (0,1) of 11B2 at 29586 cm−1 and of 11B10B at 29560 cm−1, corresponding to 1042±30 and 1068±30 cm−1 for vibrational modes in the electronic ground state, were recorded in emission. An absorption line recorded at 1066.5±0.5 cm−1 in infrared spectra after photolysis of either B2H6 in Ne or B2D6 with D2 in Ne is thus attributed to 11B10B. Caught in photolysis: After irradiation of B2H6 dispersed in solid neon at 4 K with far ultraviolet light, the vibrational modes of B2 in ultraviolet emission and absorption and in infrared absorption spectra were identified.