When this polyatomic ligand is bonded to a trimethylsilyl group, but not a similar tert-butyl group, it rapidly interconverts which of its atoms is bonded to the group. A compound of cobalt(II) and this ligand is a cubic lattice with another cobalt atom inside half of the cubes, giving a zeolite-like structure. Compounds of transition metals with this ligand form the widest variety of, and best studied, coordination (*) polymers, as this ligand is the simplest (10[1])to have two atoms that both readily bond to metal centers. The most common method of gold refining (10[1])forms a complex of gold with this ligand that is water-soluble. Iron(II) complexed to six instances of this ligand (-5[1])is a component of Prussian blue. For 10 points, (10[1])name this toxic (10[1])anion made of a triple-bonded carbon (-5[1])and nitrogen. (10[1])■END■ (10[2]0[1])