金属錯体, 配位子場分裂, 槌田龍太郎の分光化学系列
Every physical property of the metal complex, such as an electronic conductivity, a magnetic spin state and an optical property, can be determined by the size of the ligand field splitting width of the d- or f-electron orbital of the central metal ion. Therefore, for controlling freely of the physical properties of the metal complexes, it is very important to find the way for changing freely of the sizes of the ligand field splitting widths of the metal complexes. There are some basically textbook examples of the ligand field splitting such as the crystal field theory, ligand field theory, Tanabe-Sugano diagram, and the Tsuchida's spectrochemical series that is the most powerful strategic system for the metal complexes. To change the ligand field splitting width is very difficult, for example, it is very difficult to understand the Tanabe-Sugano diagram because the values on the T-S diagram are all written in a unit of the Racah parameter. For using the Tsuchida's spectrochemical series, only in the case of cobalt ion can be used for the order of the ligand molecules, whereas only in the cases of the H2O and NH3 ligand molecules are availavle of the order of the metal ions. Recently, we have reported the novel 2D universal spectrochemical series, which can be applied for estimating the sizes of the ligand field splittings of any combinations of the central metal ions and the ligand molecules of the metal complexes. Using the nobel 2D universal spectrochemical series, we can use not only for analyzing the size of the ligand field splitting of the known metal complex, but also for predicting the size of the ligand field splitting of unknown metal complex. The electronic theory method is more powerful and more effective not only for discussing the absorption spectrum of the metal complex but also for discussing the emission spectrum of the dinuclear copper complex. Now, we are trying to disappear the way for investigating the high- or low-spin state of the magnetic property by means of the size of the ligand field splitting.
