CHEM 324 Lecture Notes - Lecture 5: Coordination Complex, Effective Nuclear Charge, Battletech

• School: University of Victoria
• Department: Chemistry
• Course: CHEM 324
• Professor: Robin Hicks

Document Summary

Many, many properties of transition metal complexes (coordination number, structure, colour, magnetism, reactivity) are very sensitive to the number of d-electrons and how they are arranged in the d-orbitals . For the transition element valence orbitals the energy-ordering is: ns < (n-1)d < np eg. fe:[ar]4s2 3d6 zr:[kr]5s2 4d2. But for higher oxidation states, mn+, the energies of (n-1)d orbitals tend to be lower in energy than the ns orbitals. Recall: orbital energies affected by principal quantum number (n), effective nuclear charge experienced by electrons (zeff) and e -e repulsions as subshells are filled. Removal of one or more electrons (oxidation) reduces overall e repulsion and lowers energy; this effect is most pronounced for d-orbital energies, relative to s or p. e. g. element. Assuming you can put 4s electrons into 3d orbital when you can for a metal complex. E. g ti 3+ has a d1 con guration, cr 3+ is d3, v 5+ is d0.