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Topic: Coordination Chemistry and Complexes  (Read 3542 times)

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Offline anap40

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Coordination Chemistry and Complexes
« on: November 28, 2007, 09:03:30 AM »
The Question
a)If manganese reacts with CO and PH3 ligands to form a stable, tricarbonyl 5 coordinate complex, what manganese oxidation state and charge for the complex can be expected? Why?

b)If the complex is diamagnetic how is manganese hybridized and what is the geometry of the complex?

c)The stability of this complex should increase if PH3 Ligands are replaced with PF3 ligands. Why?


What I know

For part a the complex should be called tricarbonyldiphosphinemanganese(II)
It is a Mn surrounded by 3 CO and 2 PH3 and the C's and P's are bonded to the Mn.

For Part A)
I think the oxidation state should be 2 but only because that is what Mn normally is.
Also, the charge should be 2+ because the Mn is probably 2+ and CO and PH3 are nuetral.

For Part B)
My guess is sp3d hybridized with a trigonal bipyramidal shape.
I only say this because that is the shape and hybridization of a molcule w/ 5 atoms bonded to it. Is there anything different that needs to be done when considering coordination complexes?

For Part C)
I really don't know why PF3 ligands would make it more stable, my only guess would be that F is much more electronegative so would stabilize the electron density better.

Thanks for any help.

Offline AWK

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Re: Coordination Chemistry and Complexes
« Reply #1 on: November 28, 2007, 09:48:08 AM »
If you use metallic manganese, CO and PH3 (all are neutral species), why do you think oxidation number or Mn will be +2?
« Last Edit: November 29, 2007, 01:17:24 AM by AWK »
AWK

Offline anap40

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Re: Coordination Chemistry and Complexes
« Reply #2 on: November 28, 2007, 10:31:04 AM »
Because I think when you get the oxidation state(which is not the same as Oxidation number) for a coordinate complex, you just take away all the electrons that the ligands donated.

Offline anap40

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Re: Coordination Chemistry and Complexes
« Reply #3 on: November 29, 2007, 07:50:38 AM »
Now I am not really sure about the Mn being 2+.
I figured out part C(it has to do with back bonding)

I think that if I can figure out the oxidation state in part A, I will be able to do part b also.

I would appreciate any help on how to find the oxidation state.

 Thanks

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