4'1 Carter

1
Homework problem
Approach 1 --- use Tanable Sugano Diagram for d8
...the ratio of the two energies can be fitted
to the (Tanabe Sugano) diagram by sliding a ruler
along the abscissa until a point is found at
which the measured energy level separations have
this same ratio. Huheey, page 446
2
Note--- An examination of the 3T2 energy
dependence shows that E/B ?/B so that E ? for
this state. Therefore ? can be directly
obtained observed lowest energy absorption
frequency
These ratios were obtained by sliding a ruler
across the TS diagram to get the best fit to the
observed ratios obtained on the previous page
E/B ?/B
E/B 8.0
8500 cm-1 /B 8.0
B 1063
?/1063 8.0
? 8500 cm-1
?/B 8.0
3
Homework problem (11.21 Huheey)
Alternative - in all complexes the metal ion is
Ni2 (d8), which has a free ion 3F ground term.
The energy level diagram is therefore the same as
that for Cr3, except for spin multiplicities. If
you have three observable energy bands, you can
accordingly use Eqs. 11.20 and 11.21 in Huheey to
calculate ?o and B?. These are obtained from
equations 11.22, 11.23 and 11.24.
to give
15 B? ?3 ?2 - 3?1
The results are Complex ?o (cm-1)
B?(cm-1)
Ni(H2O)62
8500 1060
Ni(NH3)62
10750 897
Ni(OSMe2)62
7728 922
Ni(dma)62
7576 921