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Chemistry Forums for Students => Inorganic Chemistry Forum => Topic started by: ajones51 on October 25, 2008, 03:57:30 PM

Title: point groups
Post by: ajones51 on October 25, 2008, 03:57:30 PM

Can someone please help me determine the point groups of all of the isomers of Fe(CO)4(PPh3)?

I think the isomer with PPh3 axial is C3v and with PPh3 equatorial is C2v. However for the one that I think is C3v, I think that there are perpendicular axes to the principal axes, making it a D3d group. I'm confused. Can anyone please tell me what the correct point groups of the isomers of Fe(CO)4(PPh3) are?

Thanks.

Title: Re: point groups
Post by: Mitch on October 25, 2008, 04:02:46 PM

You mean Fe(CO)₄(PPh₃)₂?

Title: Re: point groups
Post by: ajones51 on October 25, 2008, 04:11:44 PM

No I mean Fe(CO)4(PPh3). It is a five-coordinate complex.

Title: Re: point groups
Post by: FeLiXe on October 25, 2008, 04:49:48 PM

for the axial PPh3 C3v sounds correct (assuming that the phenyl rings are aligned correctly). a way to understand why it cannot be D3d is the following: atoms that occur only once have to be on every symmetry axis. you have Fe and P, they are on the one and only symmtry axis. every other rotational axis would move at least one of them around

The other one is Cs in my opinion: you could not have a two-fold symmtery axis when you have 3 phenyl rings on the P atom