Coordination Chemistry – Bonding
Chapter 10: pp 369 – 380
HW: 10 16 18 19 20 21 22 23 24a 25
Slides: Nov_6inked
This will help you to visualize d-d transitions: http://firstyear.chem.usyd.edu.au/calculators/dd.shtml
Goals: Draw accurate crystal-field splitting diagrams; Construct MOs for coordination compounds.
We got through CFT and sigma bonding LFT; we’ll talk about pi bonding LFT on Wednesday
I’m having some trouble on question10.20, which says, “oxygen is more electronegative than nitrogen; fluorine is more electronegative than the other halogens. Fluoride is a stronger field ligand than the other halides, but ammonia is a stronger field ligand than water. Why?
What is the trend for strong/weak field ligands exactly? I know that it has to do with pi donor/acceptor behavior. Does that mean that ammonia becomes more stabilized since it accepts pi electrons?
Great question! You’re on the right track, as it does concern pi-donor or acceptor capability. Ask yourself this: Can NH3 be a pi donor? Can H2O be a pi donor?
A ligand can only be a pi donor if there is a second lone-pair. And pi-donors decrease Del-oh, making them weak-field ligands.