Flash photolytic and other studies on the boron trihalides

Commercially available boron triiodide (stated to be 99.9% pure) was flash photolysed and found to contain a high level of impurity. After a lengthy purification procedure the sample was still too impure to be of use. Boron triiodide was, therefore, prepared by several methods and shown to be free of impurities by mass spectrometry. A detailed study of these preparative methods has removed many of the ambiguities present in the existing literature. The absorption spectrum of the water sensitive pure B13 vapour was recorded over the range 650-200nm and shown to consist of six absorption maxima ie. transitions to six electronic states of the B13 molecule were detected.....