Formation of Aminoxy and Oxo Complexes from the Reaction of Nb(NMe₂)₅ with O₂ and the Crystal Structure of Nb(NEt₂)₅

The reaction of Nb(NMe(2))(5) with O(2) gives three complexes: monomeric (Me(2)N)(n)Nb(eta(2)-ONMe(2))(5-n) (n = 3, 4) and dimeric (Me(2)N)(4)Nb(2)[eta(2)-N(Me)CH(2)NMe(2)](2)(mu-O)(2). Nb(NEt(2))(5) was prepared in a mixture of pentane and THF, leading to its purification and characterization by single-crystal X-ray diffraction. Unlike Nb(NMe(2))(5), which adopts a square pyramidal structure, Nb(NEt(2))(5) is a distorted trigonal bipyramid. The reaction of Nb(NEt(2))(5) with O(2) gives an insoluble white solid.