Copper and Silver Trispyrazolylborate-Phosphinoazide Complexes: Synthesis, Characterization, and Nitrene Generation.

Phosphinoazide complexes of the composition TpM-L (M = Cu, Ag, and L = 2-azido-1,3-bis(2,6-diisopropylphenyl)-2,3-dihydro-1-1,3,2-diazaphosphole) have been synthesized and structurally characterized. Their thermal decomposition led to cyclodiphosphazenes as a result of the metal-mediated coupling of two nitrene units in a process that takes place in both a stoichiometric and catalytic manner. Experimental data have allowed proposing a mechanistic pathway for this new transformation.