Two different crystallizing methods produced different structural complexes 1 and 2 using the same metal salt and the same bidentate organic ligand, 2,9-diethoxy-1,10-phenanthroline (L), in the same solvent. They are one monomer [Cd(L)2(H2O)] [CdCl4]·CH3OH (1) and one dimmer [Cd2(L)2Cl4] (2). Complex 1 is a CdIIcomplex containing one cationic part [Cd(L)2(H2O)]2+and one anionic part [CdCl4]2−. Complex 2 is a CdIIdimer bridged by chloride atoms. Furthermore, fluorescent properties of these two coordination compounds have been measured. [ABSTRACT FROM AUTHOR]