The invention relates to bimetallic complexes in which the ligand contains a salophen unit which complexes copper, manganese or cobalt and a phenanthroline unit which complexes palladium and the two systems are linked by a continuous conjugated system. The invention further relates to the use of these bimetallic complexes as catalysts for the oxidative carbonylation of aromatic hydroxy compounds to form diaryl carbonates, a process for preparing diaryl carbonates using the bimetallic complex as catalyst and also diaryl carbonates prepared by oxidative carbonylation of aromatic hydroxy compounds using the bimetallic complexes of the invention as catalysts.