Boron compounds suppliers

A simple Lewis acid is BF3. As you saw in Chapter 5, monomeric boron compounds have three bonds to other atoms and an empty p orbital, making six electrons only in the outer shell. They are therefore not stable and BF3 is normally used as its etherate a complex with EtjO. Ether donates a pair of electrons into the empty p orbital of BF3 and this complex has tetrahedral boron with eight electrons. In this reaction the ether donates electrons (it can be described as a Lewis base) and BF3 accepts electrons it is a Lewis acid. No protons are exchanged. The complex is a stable liquid and is the form usually available from suppliers. 

Boron trichloride, BCI3. Mol. wt. 117.19, b.p. 13°. Supplier Matheson. Review. Purification through the nitrobenzene addition compound. ... 

A large number of heterocyclic boronates and, to a lesser degree, stannanes are available conunercially. Included in the suppliers lists are many compounds, the preparations and properties of which do not appear in the literature. They are often noted in papers just as reagents for syntheses of libraries for biological testing and, although this may be a practical approach, it is scientifically unsatisfactory because there is no trail of characterization, particularly as some of these compounds, for example azine a-boronates, are significant from a theoretical viewpoint. 

Aqueous dilutions in water of 20° German hardness were used in the tests. From the suppliers data sheets, the boron-containing compounds can be characterised as follows ... 

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