ISSN:
1434-1948
Keywords:
Molybdenum
;
Fluxionality
;
Pyridylphosphanes
;
Phosphane oxides
;
Polydentate ligands
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The pseudo-octahedral complexes [Mo(η3-allyl)Br(CO)2(PPynPh3-n-P,N)] (Py = 2-pyridyl; n = 2, 3) and [Mo(η3-allyl)Br(CO)2(OPPymPh3-m-O,N)] (m = 1, 2, 3) undergo three different dynamic processes in solution, depending on the chelating ligand. The complexes containing PPhPy2 and PPy3 as chelating P,N-donors undergo a novel “pivoted double switch” mechanism which scrambles two equatorial coordination sites with racemization, while maintaining the identity of the phosphorus atom trans to the allyl ligand. The complexes containing 2-pyridylphosphane oxides as chelating O,N-donors undergo a nondissociative intramolecular trigonal-twist (or turnstile) rearrangement which maintains the identity of the phosphane oxide oxygen atom coordinated in an equatorial position. All the complexes containing uncoordinated pyridyls undergo a slow dissociative exchange of pyridyls without coordination site scrambling. The structure of the complex [Mo(η3-allyl)Br(CO)2(OPPy3-O,N)] has been determined by X-ray diffraction.Supporting information for this article is available on the WWW under -//_/_http://www.wiley-vch.de/contents/jc_2005/2000/99363_s.pdf or from the author.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
Permalink
