A new dissymmetric thiosemicarbazone ligand containing a hydrazonequinoline arm, H2AMeTsQ, and its chloride salt, [H3AMeTsQ]Cl, were synthesized. Nine new complexes of cadmium and mercury with different structural characteristics were obtained under different reaction conditions as the ligand charge can be controlled by varying the amount of base. 113Cd and 199Hg NMR spectroscopy together with X-ray diffraction indicated that the complexes form monomeric and dimeric structures and even a coordination polymer. Fluorescence spectroscopy showed that both protonated and neutral forms of the ligand were fluorescent as well as some of their cadmium and mercury derivatives. The fluorescence intensity decreased upon complexation and in some complexes a shift of the emission maximum was also observed.