154888-75-2Relevant academic research and scientific papers
Osmium Complexes of the Half-Sandwich Type with Oximes, Imines, and Azavinylidenes as Ligand
Daniel, Thomas,Knaup, Wolfgang,Dziallas, Michael,Werner, Helmut
, p. 1981 - 1994 (2007/10/02)
Azavinylideneosmium complexes of the general composition X (L = PMe3, PMetBu2, PiPr3) have been prepared by two methods.The first one uses the hydrido compound (2) and oximes HON=CRR' as starting materials and proceeds via the oxime complexes (PMetBu2)>PF6 (10, 11) as intermediates.They react with Al2O3 with elimination of water to give the final products 6-9.The second method starts with the dichloro- or diiodoosmium(II) compounds (14, 16, 19, 21; arene = C6H6, 1,3,5-Me3C6H3; R = Me, iPr) which upon treatment with HN=CPh2 or imine derivatives XN=C(R)Ph (X = Li, SiMe3) afford the azavinylidene complexes 13b, 18, 23, 33.In the reactions with HN=CPh2, the corresponding imine complexes X (15, 17, 20, 22) are formed as the primary products.Whereas nucleophilic addition of H- and CH3- to the N=C carbon atom of + (6) gives the imidoosmium(II) compounds (24, 25), the reaction of PF6 (13b) with LiAlH(OtBu)3 yields the hydrido(imino) derivative PF6 (26).The bis(azido) complex (27), which is prepared either from 13b or (14) and NaN3, undergoes a cycloaddition reaction with C2(CO2Me)2.Two isomeric (triazole)osmium compounds 28, 29 have been isolated.Treatment of PF6 with HX (X = O2CCF3) leads to addition of the acid to the Os=N bond and, for a five-membered metallaheterocycle 31.The X-ray structural analysis of PF6 (6) reveals an allenelike arrangement of the ligands and substituents around the Os=N=C unit. - Key Words: Azavinylidene osmium complexes, preparation from oximes or imines/ Hydrido(oxime) osmium complexes/ Chloro-, hydrido- and iodo(imine) osmium complexes/ Imido osmium complexes, formation by nucleophilic addition/ Triazole osmium complexes, preparation from a bis(azido) osmium(II) compound and alkyne
