Terminal Phosphinidene Complex Adducts with Neutral and Anionic O-Donors and Halides and the Search for a Differentiating Bonding Descriptor

Abstract

The stability and some characteristic bonding features of a variety of ligand (L)-stabilized phosphinidene complexes derived from adduct formation with halides, and both anionic or neutral O-donor bases were explored. Furthermore, the main features of L → P pnictogen bonding in such adducts were studied not only by using geometric criteria such as L–P bond distances and pyramidalization or planarity at P but also by turning the spotlight on bond-strength-related (including atoms-in-molecules-derived) parameters, thermodynamic stability dependence with electronic characteristics of the free ligand, and dative-bonding participation. We propose the new relative positions of the charge concentration band descriptor, τVSCC, which, together with the sign and magnitude of ∇2ρ at the bond critical point, constitutes the required criteria to differentiate L–P linkages as van der Waals interactions, dative bonding, or mostly covalent bonds.

Synthesis of the First Oxaphosphirane Iron Complexes

“…Since the first oxaphosphirane complex formation by formal cheletropic cycloaddition of a carbonyl component with a P 1 fragment coming from a in situ generated phosphinidene complex, an initial nucleophilic attack from O to the electrophilic phosphinidene P atom was assumed. [11] Only very recently, this was computationally proven [12] which was previously shown only for the reaction with imines. [13] However, the most recent and syntheticcally very useful "similar" reaction of Li/Cl phosphinidenoid complexes with carbonyl compounds has never been computationally explored, neither for the "classical" zerovalent group 6 pentacarbonyl complexes nor the herein reported reaction with tetracarbonyliron(0) fragments.…”

Synthesis of azadiphosphiridine complexes. Theoretical studies on ring formation, the P-to-P′ metal shift and the resulting nitrogen geometry

“…The bonding situation of 8′e might be best described by two covalent P–W bonds with scarce dative bonding character, as deduced from the Bader's quantum theory of atoms in molecules. The comparatively high ∇ 2 ρ value for the P–W BCP in chelate 8′e indicates an increased covalent bond character, compared to the vanishing value displayed in case of 3′e fully confirming its dative bonding character 22 (see the ESI‡ for a more detailed analysis).…”

1,2σ3λ3-Oxaphosphetanes and Their P-Chalcogenides—A Combined Experimental and Theoretical Study

“…By elimination of the solvated LiCl salt 8 , terminal phosphinidene-epoxide adduct 9 was formed in a markedly endergonic transformation, for which a TS could not be located. The singularity of a terminal phosphinidene pentacarbonyltungsten(0) oxirane adduct was recently studied [ 32 ], showing the weakest O→P bond among the whole series of cyclic ethers adducts of phosphinidene complexes. In contrast, complex 9 displayed a strengthened P→O bond with similar bond strength descriptors values than those obtained when the O donor is dimethyl ether 9 OMe2 ( Table S1 ).…”