Synthesis and Multiple Subsequent Reactivity of Anionic cyclo‐E₃ Ligand Complexes (E=P, As)

Abstract

A synthetic pathway for the synthesis of novel anionic sandwich complexes with a cyclo‐E3 (E=P, As) ligand as an end deck was developed giving [Cp′′′Co(η3‐E3)]− (Cp′′′=1,2,4‐tri‐tert‐butylcyclopentadienyl, E=P ([5]), As ([6])) in good yields suitable for further reactivity studies. In the reaction with the chlorophosphanes R2PCl (R=Ph, Cy, tBu), neutral complexes with a disubstituted cyclo‐E3P (E=P, As) ligand in [Cp′′′Co(η3‐E3PR2)] (E=P (7 a–c), As (9 a–c)) were obtained. These compounds can be partially or completely converted into complexes with a cyclo‐E3 (E=P, As) ligand with an exocyclic {PR2} unit in [Cp′′′Co(η2:η1‐E3PR2)] (E=P (8 a–c), As (10 a–c)). Additionally, the insertion of the chlorosilylene [LSiCl] (L=(tBuN)2CPh) into the cyclo‐E3 ligand of [5] and [6] was achieved and the novel heteroatomic complexes [Cp′′′Co(η3‐E3SiL)] (E=P (11), As (12)) could be isolated. The reaction pathway was elucidated by DFT calculations.

Synthesis of a carborane-substituted bis(phosphanido) cobaltate(i), ligand substitution, and unusual P4fragmentation

“…38,39 Instead, X-ray crystallographic analysis (vide infra) revealed the unexpected fragmentation of P4 shown in Scheme 5. The anion [meso-8]⁻ represents a rare anionic cyclo-P3 cobalt complex, the only other reported examples are [39][40][41] Furthermore, instead of the expected dianionic bis(phosphanido) ligand, [meso-8]⁻ features a monoanionic triphospholanido ligand, in an unprecedented η 3 -coordination mode.…”

Synthese und mehrfache Folgereaktivität von anionischen cyclo‐E3‐Ligandkomplexen (E=P, As)

“…[2,9,19] Aufgrund der weitaus grçßeren Ausbeuten von [K(thf) 0.7 ] [5] [5]und [6]imF estkçrper. [31] Gegenanionen, Lçsungsmoleküle und H-Atome sind weggelassen. Thermische Ellipsoide sind mit 50 %A ufenthaltswahrscheinlichkeit dargestellt.…”

“…Molekülstruktur von 7b, 7c, 8a, 9b, 9c, 10 a und 10 b im Festkçrper. [31] H-Atome sind weggelassen. Thermische Ellipsoide sind mit 50 %A ufenthaltswahrscheinlichkeit wiedergegeben.…”

“…Abbildung 1. Molekülstruktur der Anionen[5]und[6]imF estkçrper [31]. Gegenanionen, Lçsungsmoleküle und H-Atome sind weggelassen.…”

Transformation of the cyclo‐P5 Middle Deck in [(Cp*Fe)(Cp’’’Co)(μ,η5:η4‐P5)] upon Functionalization – A Comprehensive Study of Reactivity

“…Apart from that, the reactivity of the cyclo ‐P 4 ligand in [Cp’’’Co(η 4 ‐P 4 )] was explored by our group towards carbon‐based nucleophiles with endo‐substituted tetraphosphido complexes [Cp’’’Co(η 3 ‐P 4 R)] − ( VIII , R= t Bu, CH 2 SiMe 3 , Scheme 1b) being isolated [11] . In addition, the reactivity of the anionic cyclo ‐P 3 complex [Cp’’’Co(η 3 ‐P 3 )] − towards chlorophosphines was analyzed yielding complexes revealing finally P 3 ‐{PR 2 }‐type ligands [12] . Via cationic functionalization of the cyclo ‐P 5 end‐deck in [Cp*Fe(η 5 ‐P 5 )] ( IX ), an unprecedented diversity of p‐block element moieties can be attached to the pnictogen ligand in which the aromatic character of the resulting pentaphosphole derivative is achieved ( X , Scheme 1c) [13] .…”