Assignment
I
CHEM 495 T-Metals
Exams and Assignments
The following is for your assistance and practise, but is not for credit.
Q. Determine the oxidation state of the metal, its dn total electron count,
and the total number of electrons in each of the following compounds. Which
of these compounds will be stable? (Hint - they may not be monomers).
(a) Cp3ZrMe2
(b) Rh(H)(CO)(dppe)2
(c) [Cr(H)(CO)2(dppe)2]+
(d) Cp3TaMe2
(e) WH6(PMe3)3
(f) Rh(O2CCH3)2
(g) Mo(N2)2(PPh3)4
Answers:
|
OXIDATION STATE |
dn
|
total
e-
|
stable
|
Comments
|
|
|
(a)
Cp3ZrMe2
|
+5
(!)
|
n/a
|
n/a
|
n/a
|
|
|
(b)
Rh(H)(CO)(dppe)2
|
+1
|
d8
|
20
|
no
|
dppe
is bidentate
|
|
(c)
[Cr(H)(CO)2(dppe)2]+
|
+2
|
d4
|
18
|
yes
|
can
salso be Cr0
|
|
(d)
Cp3TaMe2
|
+5
|
d0
|
18
|
yes
|
1 Cp
is
|
|
(e)
WH6(PMe3)3
|
+6
|
d0
|
18
|
yes
|
|
|
(f)
Rh(O2CCH3)2
|
+2
|
d7
|
16
|
yes
|
dimer with Rh-Rh bond |
|
(g)
Mo(N2)2(PPh3)4
|
0
|
d6
|
18
|
yes |