Synthesis and Reactivity of an End‐Deck cyclo‐P₄ Iron Complex

Abstract

Reduction of the Fe complex [( PP )FeCl ] (2) generated an electron-rich and unsaturated Fe species, which was reacted with white phosphorus. The resulting new complex, [( PP )Fe(η -P )] (3), is the first iron cyclo-P complex and the only known stable end-deck cyclo-P complex outside Group V. Complex 3 features an Fe center, as shown by Mössbauer spectroscopy, associated to a P fragment. The distinct reactivity of complex 3 was rationalized by analysis of the molecular orbitals. Reaction of complex 3 with H afforded the unstable complex [( PP )Fe(η -P )(H)] (4), whereas with CuCl and BCF, the complexes [( PP )Fe(η :η -P )(μ-CuCl)] (5) and [( PP )Fe(η :η -P )B(C F ) ] (6) were formed.

[3+2] Fragmentation of a Pentaphosphido Ligand by Cyanide

“…However, the single‐crystal X‐ray diffraction analysis of an adduct [K(18c‐6)][(PHDI)Co(μ 2 :η 1 ,η 4 ‐P 4 )W(CO) 5 ] ([K(18c‐6)] 3 ; Scheme , reaction c), formed quantitatively from [K(18c‐6)] 2 and [W(CO) 5 (thf)] according to monitoring by 31 P NMR spectroscopy, revealed an ordered structure (see Figure S58). An almost square, η 4 ‐coordinated cyclo ‐P 4 unit similar to those in related complexes is observed . The P−P bond lengths (2.132(4) to 2.173(5) Å, mean: 2.147(7) Å) are in‐between the values expected for P−P (2.22 Å) and P=P bonds (2.04 Å) and suggest the presence of a ( cyclo ‐P 4 ) 2− dianion .…”

[3+2]‐Fragmentierung von Pentaphosphidoliganden durch Cyanid

“…Eine graphische Abbildung der Molekülstruktur ist in den Hintergrundinformationen gezeigt (Abbildung S58). Die annähernd planare cyclo ‐P 4 Einheit weist P‐P‐Bindungslängen von 2.132(4) bis 2.173(5) Å auf (Mittelwert: 2.147(7) Å); diese liegen somit im Bereich von anderen cyclo ‐P 4 ‐Komplexen sowie zwischen den erwarteten Werten für P‐P‐Einfach‐ (2.22 Å) und P=P‐Doppelbindungen (2.04 Å) . Laut einer kürzlich erschienen Arbeit von Figueroa und Mitarbeiter sind solche Strukturparameter typisch für einen dianionischen ( cyclo ‐P 4 ) 2− ‐Liganden .…”

Transition‐Metal‐Mediated Functionalization of White Phosphorus

“…Mézailles and co‐workers investigated the reactivity of the end‐deck cyclo ‐P 4 iron complex 119 toward electrophiles (Scheme 19 b). [62] The P‐borylated Lewis adduct 120 is formed in an equilibrium reaction upon treatment of 119 with B(C 6 F 5 ) 3 in DCM.…”