Phosphenium-Übergangsmetallkomplexe XXVIII. PH-funktiionalisierte phosphametallacyclen C5R5(OC)2WPH(t-Bu)-X (RH, Me; XS, Se, Te) mit Dreiringstruktur

Chemistry of the Oxophosphinidene Ligand. 1. Electronic Structure of the Anionic Complexes [MCp{P(O)R*}(CO)2]−(M = Mo, W; R* = 2,4,6-C6H2tBu3) and Their Reactions with H+and C-Based Electrophiles.

“…The environment around phosphorus, however, is rather unusual because, instead of displaying a tetrahedral environment, the P, Mo, C(3), and C(31) atoms are placed almost in the same plane (sum of X-P-Y angles 358.4°), while the oxygen atom is placed out of this plane, over the Mo-P bond, this implying a very acute Mo-P-O and P-Mo-O angles.This unnatural geometry is in part forced by the simultaneous coordination of the P and O atoms to phosphorus, and also in part derived from the steric repulsions operating between the supermesityl group and the MoCo(CO) 2 fragment. Interestingly, a similar environment around phosphorus has also been found for the isoelectronic thiophosphinite complexes [WCp(κ 2 -SPCl t Bu)(CO) 2 ], 24 [WCp{κ 2 -SPMeN(SiMe 3 ) 2 }(CO) 2 ], 25 and [Mo(C 6 H 7 )(κ 2 -SPMe 2 )(CO) 2 ]. 26 We note that no other complexes containing P,O-bound phosphinite ligands appear to have been reported previously.…”

Nucleophilic behaviour of dioxo- and thiooxophosphorane complexes [MoCp(CO)2{E,P-EP(O)(2,4,6-C6H2tBu3)}]−(E = O, S)

“…A final structural feature deserving comment is the distorted trigonal pyramidal environment around the P atom, derived from the fact that this atom remains placed almost in the same plane as the Mo, O3 and C11 atoms (Σ(X-P-Y) = 354°). Although no S,P-bound phosphonothiolate complex other than 6 has been structurally characterized, we note that this local environment is also present in related O,P-bound phosphinite and phosphonite complexes, 4,5 and also in the S,P-bound thiophosphinite (or phosphinothiolate) complexes [WCp(SPCl t Bu)(CO) 2 ], 16 [WCp{SPMeN(SiMe 3 ) 2 }(CO) 2 ] 17 and [Mo(C 6 H 7 )(SPMe 2 )(CO) 2 ]. 18 Spectroscopic data in solution for the phosphonothiolate complexes 6 and 7 (Table 1 and the Experimental section) are fully consistent with their asymmetric solid-state structures and deserve no particular comment.…”

Syntheses and Structures of Transition Metal Complexes with Phosphanylphosphinidene Chalcogenide Ligands

“…This type of reactivity is standard for nucleophilic complexes and was previously found in the case of bridging nucleophilic Mo phosphinidene complexes [Mo 2 Cp 2 {μ-PH,η 6 -HMes*}-(CO) 2 ] or [Mo 2 Cp 2 {μ-κ 1 :κ 1 ,η 6 -PMes*}(CO) 2 ] 36 as well as in the case of W phosphenium complexes [Cp(OC) 2 W P{N(SiMe 3 ) 2 }(Ph)] 20 or [(C 5 R 5 )(OC) 2 WP(H)tBu]. 21 Complex 2 was isolated in a moderate yield (48%) as large orange crystals via crystallization from a DME solution layered with pentane at +4 °C. The X-ray structure of 2 clearly shows the presence of a phosphanylphosphinidene selenide ligand (Figure 1).…”

“…There are two main methods of accessing complex-stabilized phosphinidene chalcogenides. The first method is to generate the related R–PX phosphinidene chalcogenide and trap it with a transition metal. − Trapping experiments have revealed that R–PX displays singlet-carbene-like reactivity . The second method of accessing complexes with phosphinidene chalcogenide ligands is to oxidize complexes with low-valent phosphorus ligands with free chalcogens or with chalcogen sources.…”

“…The reaction of [Cp­(OC) 2 Fe–PPMes*] with S yields [Cp­(OC) 2 ­Fe–P­(S)PMes*] . The sulfurization of the phosphenium complexes [Cp­(OC) 2 WP­{N­(SiMe 3 ) 2 }­(Ph)] or [(C 5 R 5 )­(OC) 2 WP­(H) t Bu] leads to the addition of an S atom to the MP bond, while a similar reaction with the Fe­(II) phosphido complex [Cp­(OC) 2 Fe–PPh 2 ] yields [Cp­(OC) 2 ­Fe–P­(S)­Ph 2 ] . The addition of H 2 O to [dppe 2 ReCl­(P ≡ C t Bu)] gives the complex [dppe 2 ReCl­(P­(O)–CH 2 t Bu)] with a phosphinidene oxide ligand .…”