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Chemistry Forums for Students => Inorganic Chemistry Forum => Topic started by: Dolphinsiu on May 02, 2008, 06:05:37 AM

Title: Spectroscopy?
Post by: Dolphinsiu on May 02, 2008, 06:05:37 AM
Suggest a spectroscopic method to distinguish between cis- and trans- PdCl2(PPh3)2

Can we still use UV spectroscopy? but it seems both are optical inactive? Then I cannot think of other way...Do anyone have idea?
Title: Re: Spectroscopy?
Post by: AWK on May 02, 2008, 06:41:30 AM
What do you mean by term - optical inactive?
What do you mean be term - UV spectroscopy?
Title: Re: Spectroscopy?
Post by: P on May 02, 2008, 06:59:11 AM
I don't know, but, would NMR give differing chemical shifts for the different positions?? 
Title: Re: Spectroscopy?
Post by: Dolphinsiu on May 02, 2008, 09:52:25 AM
35 Cl NMR spectrometry...How to distinguish?

How about IR spectrometry? but there is no CO. Then I don't know...
Title: Re: Spectroscopy?
Post by: resc on May 09, 2008, 11:16:54 AM
Quote from: Dolphinsiu on May 02, 2008, 06:05:37 AM
Suggest a spectroscopic method to distinguish between cis- and trans- PdCl2(PPh3)2

Can we still use UV spectroscopy? but it seems both are optical inactive? Then I cannot think of other way...Do anyone have idea?

The symmetry of each is different, so NMR of solution might show stronger coupling for cis, whereas IR or Raman of solids may give information based on the different symmetries
Title: Re: Spectroscopy?
Post by: sjb on May 09, 2008, 11:27:39 AM
Picking up on Resc's comment, a faint bell in my mind ringing suggests that comparision of the Raman and IR spectra ought to work.

As the trans form is more highly symmetric, would there be no coincident peaks between the Raman and IR, or is the cis still too symmetric for this to be of use?

S
Title: Re: Spectroscopy?
Post by: Jd1828 on May 12, 2008, 09:52:30 PM
Does cryatallography count?
Title: Re: Spectroscopy?
Post by: gericox on May 14, 2008, 03:43:08 PM
ANDERSON, G.K., CLARK, H.C., DAVIES, J.A., FERGUSON, G. & PARVEZ, M.    1982.
          The Structure of cis-Dichloro-bis(triphenylphosphine)platinum(II); a Product in the Reaction of cis-[PtCl2(CO)(PPh3)] with Tin(II) Chloride.  J. Crystal. Spectr. Res., 12, 449-458.

http://scripts.iucr.org/cgi-bin/paper?a21538

Robert Jacobson : Department of Chemistry
- [ Traduire cette page ]
Martin, L. L. and Jacobson, R. A., "The Crystal and Molecular Structure of cis-Dichloro-bis(dimethyl-phenylphosphine)palladium(II)", Inorg. Chem. ...
www.chem.iastate.edu/faculty/Robert_Jacobson/publication.html - 75k


Research cover page
- [ Traduire cette page ]
※Vibrational Reorganizational Energies of the A-band Absorption in Trans-Dichlorobis(Triphenylphosphine) Palladium (II) Determined from Resonance Raman ...
chem.hku.hk/phillips/cv/fullcv.htm - 211k




and what about 31P NMR?
Title: Re: Spectroscopy?
Post by: Dolphinsiu on May 18, 2008, 06:28:55 AM
Thank you!