Reaction of metallophosphanide anions with ML_nX(X=halide)species as a simple route to heterometallic transition metal complexes

摘要

The reaction of metallophosphanides with ML_nX leads to the formation of mixed-metal clusters via complexes that consist of a metallophosphine coordinated through the lone pair on the phosphorus atom to another metal fragment.This synthetic strategy has been employed to initially form trinuclear complexes with the general formula [(Ph_2PML_n)-(OC)_2Co(mu-DMAD)Mo(CO)_2Cp](ML_n=Mn(CO)_5 3,WCp(CO)_2 4,FeCp(CO)_2 5;DMAD=dimethylacetylene-dicarboxylate)from the reaction of the anion [(Ph_2P)(OC)_2Co(mu-DMAD)Mo(CO)_2Cp]~,2,with metal halide complexes,ML_nX(X=Cl,Br).The complexes 3,4 and 5 have been characterised spectroscopically,and an X-ray crystal structure of 5 shows that the Ph_2PFe(CO)_2Cp unit has coordinated to the cobalt centre through the lone pair on the phosphorus centre.Subsequent heating of 3 leads to carbonyl loss,and metal-metal bond formation,to yield [(OC)_6CpCoMnMo(mu-CO)(mu-PPh_2)(mu_3-eta~2(//)-DMAD)],6.An X-ray structure determination of 6 confirms that it contains a'closed'metal triangle.In a related series of reactions the cluster anion [Os_3(CO)_(10)(mu-PPh_2)]~-was treated with a variety of metal-containing synthons,ML_nX.With [FeCp(CO)_2Cl] the cluster [Os_3(CO)_(10)FeCp(CO)(mu-PPh_2)-(mu-CO)] 9 was obtained in good yield,and has been shown crystallographically to consist of an osmium triangle'spiked'by an iron atom,with the Os-Fe bond bridged by the PPh_2 group and a carbonyl ligand.With [(Ph_3P)MCl](M=Ag,Au)the tetranuclear'butterfly'clusters [Os_3(CO)_(10)(mu-PPh_2)(mu-MPR_3)](10:M=Au,R=Ph;11:M=Ag,R=Me)are obtained.These two complexes have been characterised spectroscopically and crystallographically.