Photo-activation of d⁰ niobium imido azides: en route to nitrido complexes

Abstract

We report the synthesis and photo-reactivity of d(0) niobium imido azido complexes supported by β-diketiminate ligands, which leads to the unprecedented formation of nitrides through a photo-assisted intramolecular rearrangement. This provides a new entry to metal nitrides that does not require low-valent metal centers and is a rare example in which the metal-imido moiety in group 5 complexes participates in reactivity.

Group 5 chemistry supported by β-diketiminate ligands

“…65 Addition of azidotrimethylsilane to the previously described phenyl fluoride complex 118 resulted in formation of the phenyl azido complex 144. 65 Addition of azidotrimethylsilane to the previously described phenyl fluoride complex 118 resulted in formation of the phenyl azido complex 144.…”

1,2-Addition and cycloaddition reactions of niobium bis(imido) and oxo imido complexes

“…This approach has been used to trap complexes containing reactive basic functionalities in related systems. [97][98][99][100] In this case, however, the unbound oxygen of the carbamate functionality simply engaged in a Lewis acidbase interaction with the triarylborane to generate 20, which was isolated as purple crystals in 45% yield (Scheme 4). The Xray crystal structure of 20 (Fig.…”

On the non-innocence of “Nacnacs”: ligand-based reactivity in β-diketiminate supported coordination compounds

“…230,231 Since subsequent negative charge is lying on the CH 2 unit, in some instances the ligand rearranges intramolecularly to bind in a N,C-chelating mode (Scheme 57). Deprotonation of the β-Me position 9.1 A diverse array of structures BDI ligands featuring β-Me groups are well known to undergo deprotonation at the β-Me carbon position.…”

“…abstracts a hydrogen from the BDI ligand to form the final product shown in Scheme 63. 230 Similarly, migration of a hydrogen atom from a β-Me group from the ligand backbone precluded the isolation of BDI compounds containing GevN double bonds (Scheme 64). The four-coordinate bis(imido) species (BDI*)Nb(N t Bu) 2 undergoes clean thermal decomposition at room temperature to form (#BDI*)Nb(NH t Bu)(N t Bu) (Scheme 64) via a C-H activation process involving one imido ligand.…”