280767-98-8Relevant academic research and scientific papers
Structure and dynamic behavior of (η3- allyl)bromodicarbonylmolybdenum(II) complexes containing polydentate 2- pyridylphosphanes or their oxides as chelating ligands: Occurrence of three fluxional processes
Espinet, Pablo,Hernando, Rosa,Iturbe, Gonzalo,Villafane, Fernando,Orpen, A. Guy,Pascual, Isabel
, p. 1031 - 1038 (2008/10/08)
The pseudo-octahedral complexes [Mo(η3-allyl)Br(CO)2(PPy(n)Ph(3-n)- P,N)] (Py = 2-pyridyl; n = 2, 3) and [Mo(η3-allyl)Br(CO)2(OPPy(m)Ph(3-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.
