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(NMe2)5 with O2 gives three complexes: monomeric (Me2N)nNb(η2-ONMe2)5−n (n = 3, 4) and dimeric (Me2N)4Nb2[η2-N(Me)CH2NMe2]2(μ-O)2. Nb(NEt2)5 was prepared in a mixture of pentane and THF, leading to its purification and characterization by single-crystal X-ray diffraction. Unlike Nb(NMe2)5, which adopts a square pyramidal structure, Nb(NEt2)5 is a distorted trigonal bipyramid. The reaction of Nb(NEt2)5 with O2 gives an insoluble white solid.