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. 2025 Jan 13;64(1):151-157.
doi: 10.1021/acs.inorgchem.4c04397. Epub 2025 Jan 2.

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

Manuel R Rodríguez  1 , Francisco Molina  1 , M Mar Díaz-Requejo  1 , Pedro J Pérez  1
Affiliations

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

Manuel R Rodríguez et al. Inorg Chem. .

Abstract

Phosphinoazide complexes of the composition TpBr3M-L (M = Cu, Ag, and L = 2-azido-1,3-bis(2,6-diisopropylphenyl)-2,3-dihydro-1H-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.

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Conflict of interest statement

The authors declare no competing financial interest.

Figures

Scheme 1
Scheme 1. (a) Representative Examples of Detected or Isolated Copper-Nitrene Species Relevant to C–N Bond Formation; (b) Phosphinonitrenes Described by Bertrand and Its Coordination to Copper and Silver Centers
Scheme 2
Scheme 2. Synthesis of TpBr3 M[P(N3)(DDD)] Adducts
Figure 1
Figure 1
ORTEP diagram of complexes 2 and 3. Hydrogen atoms are omitted.
Scheme 3
Scheme 3. Thermolysis of Complex 2 and X-ray Structure of 4
Hydrogen atoms are omitted for clarity.
Figure 2
Figure 2
Variable-temperature 31P NMR studies for complex 3.
Figure 3
Figure 3
Decomposition of phosphinoazide (1), copper- (2), and silver complexes (3) (toluene-d8, 100 °C).
Scheme 4
Scheme 4. Thermolysis of Complex 3 and the ORTEP Diagram of Complex 6, Showing the Cation on the Left and the Anion on the Right
Hydrogen atoms are omitted for clarity.
Figure 4
Figure 4
Thermolysis of phosphinoazide (1), in the presence of variable concentrations of TpBr3Cu(NCMe) (toluene-d8, 80 °C).
Figure 5
Figure 5
Correlation of kobs with [TpBr3Cu(NCMe)].
Scheme 5
Scheme 5. Proposed Mechanism for the Formation of 4 by TpBr3Cu(NCMe)
See this image and copyright information in PMC

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