Isolation of (Aryl)‐(Imino) Phosphide and (Aryl)‐(Phosphaalkene) Amide Complexes of Alkali Metals from Carbene‐Phosphinidenes under Reductive‐Thermal Rearrangements

Abstract

AbstractTwo‐electron reduction of cyclic alkyl(amino) carbene (cAAC)‐supported chloro‐phosphinidene cAAC=P−Cl (1) followed by unprecedented thermal rearrangements afforded the alkali metal complexes of (aryl)‐(cyclic alkyl(imino)) phosphides 3 a–3 c, 4 a–4 b through migration of the 2,6‐diisopropylphenyl (dipp) group from N to the P centre, and the (aryl)‐(cyclic alkyl(phosphaalkene)) amide 5 through cleavage of the CMe2−N bond followed by energetically favoured 5‐exo‐tet ring‐closure in the presence of the alkali metals Cs (3 a–3 c), K (4 a, 4 b), and Li (5). Compound 3 a was found to be photoluminescent (PL), emitting bright orange light under a laboratory UV lamp of wavelength 365 nm with PL quantum yield (ϕPL) of 2.6 % (λem=600 nm), and an average lifetime (τ) of 4.8 μs. Reaction of 3 a with CuCl and AgOTf afforded (aryl)‐(cyclic alkyl(imino)) phosphide‐stabilized tetra‐nuclear CuI (6), and octa‐nuclear AgI (7) clusters, respectively. Moreover, complexes 3 a–3 c provided a direct route for the stabilization of cyclic alkyl(aminoboryl) phosphaalkenes 8 a‐8 c when treated with 1‐bromo‐N,N,N′,N′‐tetraisopropylboranediamine.