INSERTION REACTIONS OF ISOCYANIDES WITH DIOXODIMESITYLMOLYBDENUM(VI) - CRYSTAL AND MOLECULAR-STRUCTURE OF THE MU-OXO ETA(2)-IMINOACYL DINUCLEAR COMPLEX [(C(6)H(2)ME(3)-2,4,6)MO[C(C(6)H(2)ME(3)-2,4,6)=NBU(T)](O)](2)(MU-O)

Isocyanides react with dioxodimesitylmolybdenum(VI), Mo(O)(2)mes(2) (mes = mesityl = C(6)H(2)Me(3)-2,4,6), affording three different compounds identified as dimesityl imine mes(2)C=NR, mesityl amide mesCONHR, and dinuclear mu-oxo eta(2)-iminoacyl complexes [(C(6)H(2)Me(3)-2,4,6)Mo[C(C(6)H(2)Me(3)-2,4,6)=NR](O)(2)(mu-O) (R = Bu(t), C6H11, CH2C6H5). These new complexes which have been characterized by spectroscopic methods and by X-ray crystallography in the case of R = Bu(t) represent the first examples of compounds in which bound to a high-valent metal is an eta(2)-iminoacyl group together with terminal and ore-bridged ligands. Furthermore, they constitute a new structural type for the Mo2O34+ systems in which an ore-bridged complex possesses a metal-metal bond and one terminal oxo group on each metal atom.