77260-98-1Relevant articles and documents
Direct synthesis, reactivity, fluxional behavior, and molecular structure of Cp2Mo2(CO)3[PhP(OCH2CH 2)2NH] (Cp = η5-C5H5), a compound with a dissymmetrically substituted Mo ≡ Mo Bond. Synthesis and molecular structure of Cp2Mo2(CO)3P(OMe)3
Wachter, Joachim,Riess, Jean G.,Mitschler, André
, p. 714 - 722 (2008/10/08)
The reaction of [Cp(CO)2Mo]2 (Cp = η5-C5H5) with the bicyclic aminophosphorane PhPP(H)-(OCH2CH2)2N results, at room temperature, in the formation of Cp2Mo2(CO)3(phoran) (III) (major product), Cp2Mo2(CO)5(phoran) (IV), and Cp2Mo2(CO)4(phoran)2 (V) (in which phoran represents the open tau-tomeric form, i.e., PhP(OCH2CH2)2NH, of the phosphorane). The unexpected and direct formation of the dissymmetrically CO substituted complex III, in which the Mo≡Mo triple bond is retained, appears to be restricted to phoran and was not observed for PhP(OMe)2, which may indicate that the nitrogen atom transannular to phosphorus in phoran plays a role in the reaction. Complex III undergoes addition reactions with CO and isocyanides to form IV and Cp2Mo2(CO)3(μ,η2-CNR)(phoran) (R = CMe3, CH2Ph), respectively. Its reaction with P(OMe)3 results in the formation of Cp2Mo2(CO)3P(OMe)3 (VI). X-ray diffraction studies have been carried out on III and VI. Characteristic of both structures are relatively short Mo-Mo bonds (2.504 A?, average), semibridging CO ligands, and nonlinear Cp-Mo-Mo-Cp arrangements. The dissymmetric substitution of the Mo≡Mo bond allowed the investigation of the dynamic behavior of the CO ligands by means of variable-temperature 13C NMR studies of the 13CO-enriched complex III. Evidence was obtained for a one-for-one switch process of two carbonyls, during which the third one remains unexchanged. 0276-7333/84/2303-0714$01.50/0
