| abstract |
Mono-, di-, tri- of a metal selected from the group consisting of Ca, Zn, Cu, Fe, Co, Sr, Ba, Cr, Sn, Al, Mg, Cd, Pb and La with an azo compound of formula And metal complexes of azo compounds which correspond to one of formula (1) or tautomers thereof and contain one or more guest compounds, which correspond to tetra-anions.n n n n n n n n n n Wheren n n R and R 'are independently OH, NH 2 , NH-CN, acylamino or arylamino,n n n R 1 and R 1 ′ are independently —OH or —NH 2 . |