CHEM2402/2912/2916 [Part 2]. Ligand-Field Theory and Reaction Kinetics. A/Prof Adam Bridgeman Room: 222 Email: [email protected] www.chem.usyd.edu.au/~bridge_a/chem2 Office Hours: Monday 2-4pm, Wednesday 2-4pm Other times by appointment or by chance. Where Are We Going…?.
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Ligand-Field Theory and Reaction Kinetics
A/Prof Adam Bridgeman
Room: 222
Email: [email protected]
www.chem.usyd.edu.au/~bridge_a/chem2
Office Hours: Monday 2-4pm, Wednesday 2-4pm
Other times by appointment or by chance
By the end of week 4…
Ligand-field (‘d-d’) spectroscopy
Resources
Schedule
Revision – Ligand-Field Splitting
JKB – Lecture 3, S & A 19.1
Revision – Ligand-Field Splitting
(eg)
(t2g)
(Doct)
eg
Doct
t2g
JKB – Lecture 3, S & A 19.1
Electronic Spectra of d1 Ions
eg
eg
Ti3+(aq)
Doct
t2g
t2g
excited state
ground state
JKB – Lecture 3, S & A 19.3
Electronic Spectra of High Spin d4 Ions
eg
eg
Cr2+(aq)
Doct
t2g
t2g
ground state
excited state
JKB – Lecture 3, S & A 19.3
Electronic Spectra of High Spin d6 and d9 Ions
d6
d9
excited state
ground state
excited state
ground state
Cu2+(aq)
Fe2+(aq)
Effect of Distortion on the d-Orbitals
eg
d1
Doct
t2g
d2
tetragonal elongation
JKB – Lecture 6, S & A p467
Which Complexes Will Distort?
+½d1
d1
eg
+0.6 Doct
-½d1
Doct
+⅔d2
d2
t2g
-0.4 Doct
-⅓d2
distorted octahedron
octahedron
Which Complexes Will Distort?
Doct >>> d1 >> d2
3
1
-0.4Doct - 0.33d2
yes
small
+½d1
eg
+0.6 Doct
-½d1
+⅔d2
t2g
-0.4 Doct
-⅓d2
Which Complexes Will Distort?
Doct >>> d1 >> d2
3
1
-0.4Doct - 0.33d2
yes
small
2
3
-0.8Doct - 0.67d2
yes
small
1
-1.2Doct
3
no
no
2
-0.6Doct - 0.5d1
3
yes
large
1
1
3
0
no
none
2
+½d1
eg
+0.6 Doct
-½d1
+⅔d2
t2g
-0.4 Doct
-⅓d2
Which Complexes Will Distort?
Doct >>> d1 >> d2
3
1
-0.4Doct - 0.33d2
yes
small
2
3
-0.8Doct - 0.67d2
yes
small
1
-1.2Doct
3
no
no
2
-0.6Doct - 0.5d1
3
yes
large
1
1
3
0
no
none
2
3
4
2
-0.4Doct - 0.33d2
yes
small
5
3
-0.8Doct - 0.67d2
2
yes
small
1
-1.2Doct
6
no
no
2
3
2
-0.6Doct - 0.5d1
6
yes
large
Which Complexes Will Distort?
Doct >>> d1 >> d2
+½d1
eg
+0.6 Doct
-½d1
+⅔d2
t2g
-0.4 Doct
-⅓d2
Which Complexes Will Distort?
Cr2+
Co2+
Cu2+
Jahn-Teller Theorem
Any molecule with a degenerate ground state will distort
antibonding
bonding
+
Effect on Spectroscopy
Ti3+(aq)
eg
(B)
(C)
t2g
(C)
(A)
(B)
Summary
By now you should be able to....
Practice
Practice