Boron through Thallium, the Triels

Non-classical [c/oso-CBnHi2] etc., from non-aqueous sources, are some of the most inert and weakly coordinating anions available. 

Boron is practically insoluble in water. However, and only with amorphous boron, H2O (containing either NH3 or H2S) yields H3BO3 and H2. Similarly, H2O and exposure to light slowly yield the same. 

Water hydrolyzes boron hydrides to H3BO3, H2 etc., quickly for B2H6 and B5H11, slowly for B4H10 and BioHu, only on heating B5H9 and BeHio. 

Boiling water oxidizes [BH4] to a mixture containing various polyborate anions, simplified here, while releasing H2 gas  

The borates of the Group-1 metals are soluble, and of the Group-2 metals, somewhat soluble in water, but those of most others are not. 

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