Boron trihalide chemistry

Very little is yet known about the specific chemistry of 1,3,2-diaza-boracycloalkanes. At room temperature, these compounds add hydrogen halide readily in a 1 2 molar ratio 1>. In a similar manner, boron trihalide is added at low temperatures 13>. The solid addition products of the latter reaction decompose near room temperature with cleavage of the original B—N linkages presumably leading to linear products (Eq. 9). 

The chemistry of the boron trihalides has been extensively studied. These compounds are strong Lewis acids and form a wide range of simple 1 1 adducts that have served as model compounds for the study of Lewis acid-base interactions. Many reviews of their coordination chemistry have appeared (41, 60, 66,120, 174, 178) and these are summarized in the more recent reviews appearing in the mid-1960s (41,120). 

For a general review of the boron trihalides and their addition complexes, see Greenwood, N. N., Thomas, B. S. In Comprehensive Inorganic Chemistry Trotman-Dickenson, A. F., Ed. Petgamon New York, 1973 Vol. I,p956. 

The most stable halides of boron and aluminum are the trihalides for thallium, the monohalides (TlX) are the most stable. Similarly, the most stable oxides of boron and aluminum are of the formula M2O3 for thallium, the most stable oxide is TI2O. Comment on this chemistry. 

---