CHM 4317 Study Guide - Midterm Guide: Organometallic Chemistry
Document Summary
En elements have more of that atoms character. Effective atomic number rule: donor pair vs radical method. Sigma donation to metal, pi-backbonding into anti bonding orbital of ligand. More electron rich m more back-bonding lower c-o vibration. Isoelectronic isonitriles, cnr are better sigma-donors and poorer pi-acceptors, stabilize low oxidation states. Bond lengths are longer with trans donor ligand. Intermediate = square pyramid via barry pseudo rotation. H- > pr3 > i-, me- , co, cn- > br- > cl- > nh3. Ethylene > co, cn- > h-, pr3 > me- > i- > br > cl > nh3. Depends on ew ability and pi-back bonding ability. Possible because of intial slow rearrangement that opens a coordination site without changing oxidation state. Larger indenyl > cp because of the retention of the benzene aromaticity. Most common for 18e (16e intermediate k2 ~ k-1) Enthalpy = large positive k depends on steric bulk of l.
