FORMATION AND FAC-MER ISOMERIZATION OF CATIONIC PHOSPHENIUM TRANSITION-METAL COMPLEXES FORMULATED AS [M(BPY)(CO)(3)(PN(ME)CH(2)CH(2)NME)](+) (M=CR, MO, W) AND [M(DPPE)(CO)(3)(PN(ME)CH(2)CH(2)NME)](+) (M=MO, W)

In the reaction of [M(bpy)(CO)(4)] (M = Cr, Mo, W) with pN(Me)CH(2)CH(2)NMe(OMe) under reflux with. toluene or xylene, fac-[M(bpy)(CO)(3){PN(Me)CH(2)CH(2)NMe(OMe)}] is prepared, which reacts with BF3 . OEt(2) to give, by OMe(-) abs traction from the phosphorus, a cationic phosphenium complex, fac-[M(bpy)(CO)(3){PN(Me)CH(2)CH(2)NMe}](+). The facial isomer spontaneously isomerizes into its meridional form. The isomerization rate is in the order Cr > Mo > W. [M(dppe)(CO)(3)-{PN(Me)CH(2)CH(2)NMe(OMe)}] (M = Mo, W), which is presented from [M(dppe)(CO)(3)(NCMe)] and PN(Me)CH(2)CH(2)NMe(OMe), also reacts with BF3 . OEt(2) to give [M(dppe)(CO)(3){PN(Me)CH(2)CH(2)NMe}](+), whose fac-mer isomerization is slower than that of the corresponding bpy complex.