What are axial ligands?


by CrimpJiggler
Tags: axial, ligands
CrimpJiggler
CrimpJiggler is offline
#1
Nov12-13, 04:50 PM
P: 149
In this article:
http://jredman.kombyonyx.com/thesis/Ch16.htm
they mention "axial ligands" and "peripheral ligands". What exactly does that mean? Heres the molecule they use as an example:

I can see that the porphyrin rings both have a metal ligand M binded to them. That oxygen atom which bridges the two M ligands, is that an "axial ligand"? Is it even a ligand at all, I thought a ligand meant an electrophilic species which accepts electrons from an electron doner and forms a dative bond. I'm used to oxygen atoms being an electron doner.
Phys.Org News Partner Chemistry news on Phys.org
First view of nature-inspired catalyst after ripping hydrogen apart provides insights for better, cheaper fuel cells
Following a protein's travel inside cells is key to improving patient monitoring, drug development
Team helps cancer treatment drugs get past their sticking point
Yanick
Yanick is offline
#2
Nov12-13, 06:55 PM
P: 344
Axial and peripheral refer to the positions in complexes displaying geometries like that of trigonal bipyramidal or octahedral. In the former case you can think of three ligands which make up the "base" of each pyramid as equatorial/peripheral and the two other ligands as the axial. The same idea is applied to octahedral complexes, notice the pyrrole nitrogen a are equatorial and with the bridging O being axial in both metals (so is the thing at the very top but my phone wont show me the full size picture).
CrimpJiggler
CrimpJiggler is offline
#3
Nov13-13, 08:37 AM
P: 149
That explains it, thanks a lot.


Register to reply

Related Discussions
Ligands and strong electrical fields Chemistry 1
weak and strong field ligands Biology, Chemistry & Other Homework 0
What does (en) mean in a chemical formula/ligands Biology, Chemistry & Other Homework 4
Stress, Strain - Axial loading (axial forces) Mechanical Engineering 11
phosphine ligands: trans vs. cis Chemistry 2