An alternative to the method of continuous variations for determining the stoichiometry of metal-ligand complexes is the mole-ratio method in which the amount of one reactant, usually the moles of metal, is held constant, while the amount of the other reactant is varied. Absorbance is monitored at a wavelength where the metal–ligand complex absorbs. The illustrations below show typical results: (a) the mole-ratio plot for the formation of a 1:1 complex in which the absorbance is monitored at a wavelength where only the complex absorbs; (b) the mole-ratio plot for a 1:2 complex in which all three species—the metal, the ligand, and the complex—absorb at the selected wavelength; and (c) the mole-ratio plot for the step-wise formation of ML and ML2.
Most Common Tagsabsorbance acid-base titration atomic spectroscopy calibration curve capillary electrophoresis chromatography coulometry detector determinate error electrochemistry electrophoresis emission end point equivalence point extraction FIA flow injection fluorescence gas chromatography GC gravimetry HPLC indeterminate error instrument kinetics liquid chromatography metal-ligand complexation monochromator noise optimization photoluminescence potentiometry precipitate precipitation probability reference electrode response surface sampling separation spectroscopy standard addition titration curve titrimetry voltammetry working electrode
- HPLC Sample Injection (5.00 out of 5)
- Mole-Ratio Method for Determining Metal-Ligand Stoichiometry (5.00 out of 5)
- Property Control Charts (4.00 out of 5)