{Phosphorus acids or phosphorus acid esters comprising phosphinous acid (-ester) groups (R2P(OR')) or the isomeric phosphine oxide groups (R3P=O) , i.e. R= C, R'= C, H}
{Phosphorus acids or phosphorus acid esters comprising phosphinous acid (-ester) groups (R2P(OR')) or the isomeric phosphine oxide groups (R3P=O) , i.e. R= C, R'= C, H}