Hypophosphorous acid anion

Similarly, the acid of formula H3P02 (hypophosphorous acid) also has a four-connected structure (10-XXIIa), as does its anion (10-XXIIb). 

Cz+diimine macrocycle compounds are formed by template condensations of an a-diketone (usually 2,3-butanedione or benzil), 2 + 2 with diamines, e.g., (34), or 1 +1 with tetraamines, e.g., (35) (Scheme 10). The resulting flat macrocycle cations form many stacked compounds, often with flat metal ion-containing anions, which exhibit spin coupling. The imine groups for the Ni11 compounds are reduced with NaBH4 and one of each cz+diimine function for the Co111 compounds by hypophosphorous acid.44... 

The decasulphide, P4S10, is stable in cold moist air, but acid hydrolysis at 100°C quickly produces only orthophosphate (4.94). Alternatively, if cautious alkaline hydrolysis is carried out, various thio-ated ortho anions (Chapter 9.10) can be formed as intermediate products (Table 4.17). These later react under oxidative conditions to give mostly orthophosphate, PO4", together with some phosphorous HPOf and hypophosphorous HjPOj anions. In addition, traces of phosphine, PH3, may be produced. 

Note that the product we have obtained above, HP(OH)2, is a protonated form of what we need to get, namely, H2PO2". Like phosphorous acid (H3PO3), however, hypophosphorous acid (H3PO2) and the hypophosphite anion (H2PO2") both contain tetracoordinate phosphorus, so we still need to move a couple of protons around, which we do below with the help of OH- and H2O ... 

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