Mono- and dinuclear tetraphosphabutadiene ferrate anions

Abstract

Reduction of [CpFe(μ-Br)] (1, Cp = C(CH-4-Et)) by potassium napthalenide, followed by the addition of white phosphorus, affords [K(18-c-6){CpFe(η-P)}] (2, 18-c-6 = [18]crown-6), which features a planar cyclo-P ligand. The related diiron complex [Na(THF)(CpFe)(μ,η-P)] (3) was obtained by reducing 1 with sodium amalgam in the presence of P. Protonation of 3 affords [Na(THF)][(CpFe)(μ,η-P)(H)] (4), while the reaction of 3 with trimethylchlorosilane gives the nortricyclane compound P(SiMe) as the main product.

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

“…Crystallization from toluene/ n ‐hexane gave [K(18c‐6)] 2 as dark‐turquoise crystals in up to 80 % yield (corresponding to >1.5 g of pure product). The 31 P{ 1 H} NMR spectrum of [K(18c‐6)] 2 in [D 8 ]THF shows a sharp singlet at δ =136.5 ppm (compare with the chemical shifts of δ =175.2 ppm observed for [(η 5 ‐Cp t Bu3 )Co(η 4 ‐P 4 )] (Cp t Bu3 =C 5 H 2 t Bu 3 ) and δ =114.1 ppm for [(η 5 ‐Cp Ar )Fe(η 4 ‐P 4 )] − (Cp Ar =C 5 (C 6 H 4 ‐4‐Et) 5 ) . A single‐crystal X‐ray diffraction (XRD) analysis clearly revealed the presence of a bidentate PHDI ligand and a terminal η 4 ‐coordinated cyclo ‐P 4 unit.…”

“…Monitoring of the reaction by 31 P{ 1 H} NMR spectroscopy showed quantitative [12] (Cp tBu3 = C 5 H 2 tBu 3 )a nd d = 114.1 ppm for [(h 5 -Cp Ar )Fe(h 4 -P 4 )] À (Cp Ar = C 5 (C 6 H 4 -4-Et) 5 ). [10] As ingle-crystal X-ray diffraction (XRD) analysis clearly revealed the presence of abidentate PHDI ligand and aterminal h 4 -coordinated cyclo-P 4 unit. Am ore detailed interpretation of the structure was unfortunately prevented by heavy disorder within the cyclo-P 4 unit (see Figure S57 in the Supporting Information for further details).…”

[3+2]‐Fragmentierung von Pentaphosphidoliganden durch Cyanid

“…Kristallisation aus Toluol/ n ‐Hexan ergab [K(18c‐6)] 2 in Form tief türkisfarbener Kristalle in bis zu 80 % Ausbeute (>1.5 g an reinem Produkt). Das 31 P{ 1 H}‐NMR‐ Spektrum von [K(18c‐6)] 2 in [D 8 ]THF zeigt ein scharfes Singulett bei δ =136.5 ppm [vergleiche die chemische Verschiebungen von δ =175.2 ppm für [(η 5 ‐Cp t Bu3 )Co(η 4 ‐P 4 )] (Cp t Bu3 =C 5 H 2 t Bu 3 ) und δ =114.1 ppm für [(η 5 ‐Cp Ar )Fe(η 4 ‐P 4 )] − (Cp Ar =C 5 {C 6 H 4 ‐4‐Et} 5 )] . Eine Einkristallröntgenstrukturanalyse belegt eindeutig die Anwesenheit eines zweizähnigen PHDI‐Liganden und einer terminalen η 4 ‐koordinierten cyclo ‐P 4 ‐Einheit.…”

“…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 .…”

Functionalization of Pentaphosphorus Cations by Complexation

“…As the cyclopentadienyl iron halide complex [Cp Ar Fe(m-Br)] 2 [25] had been successfully used for white phosphorus activation, [26] it was selected as the starting point for our investigation. To our surprise,the reaction of this Fe complex with [P 5 R 2 ][GaCl 4 ]s alts (R = iPr and Mes;M es = 2,4,6-Me 3 C 6 H 2 ;S cheme 1a) [23] afforded remarkable,u nsymmetrically substituted bicyclo[1.1.0]pentaphosphanes 1-R as the major product.…”