Radical Reactivity of the Biradical [⋅P(μ-NTer) P⋅] and Isolation of a Persistent Phosphorus-Cantered Monoradical [⋅P(μ-NTer) P-Et].

The activation of C-Br bonds in various bromoalkanes by the biradical [⋅P(μ-NTer) P⋅] (1) (Ter=2,6-bis-(2,4,6-trimethylphenyl)-phenyl) is reported, yielding trans-addition products of the type [Br-P(μ-NTer) P-R] (2), so-called 1,3-substituted cyclo-1,3-diphospha-2,4-diazanes. This addition reaction, which represents a new easy approach to asymmetrically substituted cyclo-1,3-diphospha-2,4-diazanes, was investigated mechanistically by different spectroscopic methods (NMR, EPR, IR, Raman); the results suggested a stepwise radical reaction mechanism, as evidenced by the in-situ detection of the phosphorus-centered monoradical [⋅P(μ-NTer) P-R].< To provide further evidence for the radical mechanism, [⋅P(μ-NTer) P-Et] (3Et⋅) was synthesized directly by reduction of the bromoethane addition product [Br-P(μ-NTer) P-Et] (2 a) with magnesium, resulting in the formation of the persistent phosphorus-centered monoradical [⋅P(μ-NTer) P-Et], which could be isolated and fully characterized, including single-crystal X-ray diffraction.

A Systematic Survey of the Reactivity of Chlorinated N P , NP and P Ring Systems.

The reactivity of the four-membered NP ring system [RN(μ-PCl) PR] (R=Mes*=2,4,6-tri-tert-butylphenyl) towards Lewis acids, Lewis bases, and reducing agents was investigated. Comparisons with the literature-known, analogous cyclic compounds [ClP(μ-NR)] (R=Ter=2,6-dimesitylphenyl) and [ClP(μ-PR)] (R=Mes*) are drawn, to obtain a better systematic understanding of the reactivity of cyclic NP species. Apart from experimental results, DFT computations are discussed to further the insight into bonding and electronic structure of these compounds.

Correction: Increasing steric demand through flexible bulk - primary phosphanes with 2,6-bis(benzhydryl)phenyl backbones.

Correction for 'Increasing steric demand through flexible bulk - primary phosphanes with 2,6-bis(benzhydryl)phenyl backbones' by Jonas Bresien et al., Dalton Trans., 2019, 48, 3786-3794.

Sterically encumbered β-diketonates and base metal catalysis.

Metal coordination complexes of the sterically hindered β-diketonate, 2,6-dimesitylbenzoyl pinacolone (esac), are reported for Co, Ni, Cu, and Zn. All four form ML2-type complexes with typical coordination behavior for late-metal β-diketonates, however the effects on established electrochemistry and reactivity vary somewhat per metal. For example, the striking chemical and electrochemical inertness of CoII(esac)2 to oxidation and disproportionation is atypical.

Increasing steric demand through flexible bulk - primary phosphanes with 2,6-bis(benzhydryl)phenyl backbones.

Sterically demanding primary phosphanes of the type RBhp-PH2 (Bhp = 2,6-bis(benzhydryl)-4-R-phenyl; R = Me, tBu) could be prepared in high yields by modification of synthetic protocols of established bulky phosphanes. The Bhp substituents simultaneously exhibit extensive steric expansiveness and high degrees of flexibility compared to other 2,6-substituted phenyl backbones, enabling a range of different-sized atoms and functionalities to be located between the flanking benzhydryl moieties. Therefore, it was also possible to isolate and fully characterize several halogenated precursors, a diazonium intermediate, as well as a dihalostibane.

Dichloro-Cycloazatriphosphane: The Missing Link between N P and P Ring Systems in the Systematic Development of NP Chemistry.

A dichloro-cycloazatriphosphane that incorporates a cyclic NP backbone could be synthesized using knowledge gained from the chemistry of N P and P ring systems. It fills the gap between the congeneric compounds [ClP(μ-NR)] and [ClP(μ-PR)] (R=sterically demanding substituent), and thus contributes to the systematic development of nitrogen-phosphorus chemistry in general. The title compound was studied with respect to its formation via a labile aminodiphosphene, which readily underwent different rearrangement reactions depending on the solvent.