by the energy of those orbitals (+0.6Δo), and summing the two. The Table below gives CFSE values for octahedral complexes with different d electron configurations. The CFSE is highest for low-spin d6 complexes, which accounts in part for the extraordinarily large number of Co(III) complexes known. The other low-spin configurations also have high CFSEs, as does the d3 configuration. CFSE CFSE High Spin Low Spin (Δo) (Δo) d 0 0 d 1 0.4 ↿ d 2 0.8 ↿ ↿ d 3 1.2 ↿ ↿ ↿ d 4 0.6 1.6 ↿ ↿ ↿ ↿ ↿⇂ ↿ ↿ d 5 0.0 2.0 ↿ ↿ ↿ ↿ ↿ ↿⇂ ↿⇂ ↿ d 6 0.4 2.4 ↿⇂ ↿ ↿ ↿ ↿ ↿⇂ ↿⇂ ↿⇂ d 7 0.8 1.8 ↿⇂ ↿⇂ ↿ ↿ ↿ ↿⇂ ↿⇂ ↿⇂ ↿ d 8 1.2 ↿⇂ ↿⇂ ↿⇂ ↿ ↿ d 9 0.6 ↿⇂ ↿⇂ ↿⇂ ↿⇂ ↿ d 0.0 ↿⇂ ↿⇂ ↿⇂ ↿⇂ ↿⇂ 10 CFSEs for Octahedral Complexes with Different Electron Configurations (in Units of Δo) are important for two reasons. First, the existence of CFSE nicely accounts for the difference between experimentally measured values for bond energies in metal complexes and values calculated based solely on electrostatic interactions. Second, CFSEs represent relatively large amounts of energy (up to several hundred kilojoules per mole), which has important chemical consequences.
by the energy of those orbitals (+0.6Δo), and summing the two. The Table below gives CFSE values for octahedral complexes with different d electron configurations. The CFSE is highest for low-spin d6 complexes, which accounts in part for the extraordinarily large number of Co(III) complexes known. The other low-spin configurations also have high CFSEs, as does the d3 configuration. High Spin CFSE (Δo) Low Spin CFSE (Δo) d 0 0 d 1 ↿ 0.4 d 2 ↿ ↿ 0.8 d 3 ↿ ↿ ↿ 1.2 d 4 ↿ ↿ ↿ ↿ 0.6 ↿⇂ ↿ ↿ 1.6 d 5 ↿ ↿ ↿ ↿ ↿ 0.0 ↿⇂ ↿⇂ ↿ 2.0 d 6 ↿⇂ ↿ ↿ ↿ ↿ 0.4 ↿⇂ ↿⇂ ↿⇂ 2.4 d 7 ↿⇂ ↿⇂ ↿ ↿ ↿ 0.8 ↿⇂ ↿⇂ ↿⇂ ↿ 1.8 d 8 ↿⇂ ↿⇂ ↿⇂ ↿ ↿ 1.2 d 9 ↿⇂ ↿⇂ ↿⇂ ↿⇂ ↿ 0.6 d 10 ↿⇂ ↿⇂ ↿⇂ ↿⇂ ↿⇂ 0.0 CFSEs for Octahedral Complexes with Different Electron Configurations (in Units of Δo) are important for two reasons. First, the existence of CFSE nicely accounts for the difference between experimentally measured values for bond energies in metal complexes and values calculated based solely on electrostatic interactions. Second, CFSEs represent relatively large amounts of energy (up to several hundred kilojoules per mole), which has important chemical consequences.
chapter_23_text.docx