Chelates of Ru-III, Rh-III, Pd-II, Os-IV, Ir-III and Pt-IV with p-dime
thylamino-, p-diethylamino-, p-chloro-, p-bromo- and p-iodo-anils of 2
-thiophene glyoxal have been prepared. In electrolytic square-planar c
omplexes of PdU and octahedral complexes of other metal ions, ligands
are coordinated through thienyl sulphur and carbonyl oxygen in quinono
id structure.