Chromates and polychromates with organic cations can be obtained by careful hydrolysis of mono-, di- or trichromate esters in the presence of organic bases. Mixtures of nitrobenzene and carbon tetrachloride are used as solvents. When nitrobenzene soluble chromates are reacted with chromate esters more condensed anions such as tri- and tetrachromates are formed. As tetra-n-butylammoniumsalt [(C4H9)4N]2Cr3O10 for the first time a trichromate was obtained that can be recrystallized undecomposed from water.