Bond lengths nitride complexes

Alkilidine tantalum complexes have also been utilized for the preparation of ni-trido Tav. Reaction of ammonia with 31 or 32 afforded nitride 33 in moderate yields [14]. The structure of 33 has been determined by single-crystal X-ray crystallography and shown to consist of a pentameric complex, as depicted in Eq. (9). All of the Ta-N bond lengths are equivalent (2.00 A), suggesting a structure with extensive delocalization of the multiple bonds. 

When the Vffl alkyl diamide complex 25 is treated at 60 atm of H2 followed by N2, the cationic dinuclear Vvi-Vv nitride 26 was isolated (Eq. (6)) [9,10]. Although there is evidence for N2 functioning as a nitride source has been described in the literature, the mechanistic details of this particular reaction has not been established. Complex 24 constitutes a rare example of a Viv nitride it is interesting to note that all of V-N bonds are of approximately the same length, namely 1.77 A. 

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