P6-Manganocen und P3-Cymantren: Konsequenzen des Einbaus von Phosphoratomen in Mn-koordinierende Cyclopentadienyl-Liganden

Clark, Timothy; Elvers, Achim; Heinemann, Frank W.; Hennemann, Matthias; Zeller, Mat­thias; Zenneck, Ulrich

doi:10.1002/1521-3757(20000616)112:12<2174::aid-ange2174>3.0.co;2-n

Cited by 12 publications

(9 citation statements)

References 19 publications

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“…There has been significant progress in the chemistry of transition‐metal complexes carrying the η 5 ‐3,5‐ t Bu 2 ‐1,2,4‐C 2 P 3 ligand 1. Although the isolobal relationship P${-\ominus \rightarrow}$ CH and diagonal relationship P/C suggest that complexes carrying this ligand should behave like the corresponding η 5 ‐cyclopentadienyl‐substituted analogues, recent work has shown that the phosphorus‐containing systems exhibit subtle differences in both bonding and reactivity 2–4. This situation suggests that further investigations could be rewarding.…”

Section: Methodsmentioning

confidence: 99%

Selective Preparation of the [3,5‐tBu₂‐1,2,4‐C₂P₃]⁻ Ion and Synthesis and Structure of the Cationic Species nido‐[3,5‐tBu₂‐1,2,4‐C₂P₃]⁺, Isoelectronic with [C₅R₅]⁺

et al. 2003

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Selective Preparation of the [3, There has been significant progress in the chemistry of transition-metal complexes carrying the h 5 -3,5-tBu 2 -1,2,4-C 2 P 3 ligand.[1] Although the isolobal relationship PMCH and diagonal relationship P/C suggest that complexes carrying this ligand should behave like the corresponding h 5 -cyclopentadienyl-substituted analogues, recent work has shown that the phosphorus-containing systems exhibit subtle differences in both bonding and reactivity. [2][3][4] This situation suggests that further investigations could be rewarding. In a new approach to this chemistry we focused on the reactivity of the interesting tricyclic C 2 P 3 compound 1 (Scheme 1), first reported by Regitz et al.[5] First, we used this species as a convenient starting point for a new selective synthetic approach to the aromatic ion [3,5-tBu 2 -1,2,4-C 2 P 3 ] À (3). Second, and again reflecting on the consequences of replacing CH groups by isolobal P atoms, we explored the possibility of utilizing 1 as a precursor to cations [C 2 tBu 2 P 3 ]+ . The published synthetic pathways to the anion 3, [6][7][8] which derive from earlier work by Becker et al., [9,10] involve reaction of PCtBu with alkali metals (M). However, this procedure is unselective, and to obtain pure 3 it is necessary to repeatedly recrystallize the moisture-sensitive alkali-metal salts to remove the second product of these reactions, the [2,4,5-tBu 3 -1,3-C 3 P 2 ]À ion. Therefore, we recognized that if the full potential of this area was to be realized, it was important to devise a more efficient and selective pathway to 3. We reasoned that if the tricyclic compound 1, which is readily formed in good to excellent yield by treating the readily accessible zirconium complex 2 with PCl 3 , [5] was treated with an alkali metal in THF, the anionic species A should be generated (Scheme 1). We then hypothesized that such a species should undergo consecutive ring-opening reactions (A!B!3) and thus selectively provide the desired anion.Reaction (RT, 2 h, THF) of 1 with Li or Na metal leads to quantitative formation of the lithium or sodium salt of 3, which confirms our ring-opening hypotheses. Both Li·3 and Na·3 react quantitatively with Ph 3 SnCl to give the known compound 3,5-tBu 2 -1-SnPh 3 -1,2,4-C 2 P 3 (4), which has been shown to be a valuable reagent for the syntheses of complexes of the h 5 -C 2 P 3 ligand. [7] We believed that 1 might react with Lewis acids to provide an entry point to the cationic [C 2 tBu 2 P 3 ] + manifold, related to the isoelectronic pentamethylcyclopentadienyl cation, a species that has recently attracted considerable attention. [11][12][13][14][15] In particular, in view of the isolobal relationship PMCH, and Scheme 1. a) PCl 3 ; b) M, THF, ÀMCl; c) Ph 3 SnCl, ÀMCl (* = CtBu; .. = lone pair; M = Li, Na.

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Section: Methodsmentioning

confidence: 99%

Selective Preparation of the [3,5‐tBu₂‐1,2,4‐C₂P₃]⁻ Ion and Synthesis and Structure of the Cationic Species nido‐[3,5‐tBu₂‐1,2,4‐C₂P₃]⁺, Isoelectronic with [C₅R₅]⁺

et al. 2003

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“…Unter den bemerkenswertesten Strukturen sind das leicht gebogene (Winkel zwischen den Ebenen 16°), neutrale und diamagnetische Hexaphosphatitanocen [Ti(η 5 ‐P 3 C 2 ) 2 ],293 das paramagnetische Pentaphosphavanadocen [V(η 5 ‐P 2 C 3 )(η 5 ‐P 3 C 2 )],294 das Hexaphosphachromocen [Cr(η 5 ‐P 3 C 2 ) 2 ],295 das Hexaphosphamanganocen [Mn(η 5 ‐P 3 C 2 ) 2 ],296 das einen ungewöhnlichen 2 A‐Grundzustand hat, sowie der Tripeldecker [(η 5 ‐P 3 C 2 )Sc(μ‐ 33 )Sc(η 5 ‐P 3 C 2 )] mit 22 Valenzelektronen 297. Weitere Arbeiten umfassen die Synthese von Ga‐, In‐ und Tl‐Derivaten298, 299 sowie (η 5 ‐P 3 C 2 )‐Metall‐Carbonyl‐Komplexen,300 die außerdem Gegenstand theoretischer Studien waren 296. 299, 301, 302 Aus den Rechnungen wurde u. a. geschlossen, dass der Diamagnetismus des Hexaphosphatitanocens auf eine signifikante Rückbindung vom Ti‐Zentrum in das LUMO des P 3 C 2 ‐Ringsystems unter Bildung einer δ‐Bindung zurückzuführen ist.…”

Section: Besondere Elektronenkonfigurationenunclassified

Phosphaorganische Chemie: Panorama und Perspektiven

Mathey

2003

Angewandte Chemie

198

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Die gesamte phosphororganische Chemie wurde mit Beginn der siebziger Jahre infolge der Entdeckung stabiler phosphororganischer Derivate mit Koordinationszahlen des Phosphors von 1 oder 2 aufgefrischt. Bezüglich ihrer Chemie gleichen diese Verbindungen ihren reinen Kohlenstoff‐Analoga. Dieser Aufsatz widmet sich der Analogie zwischen den Phosphorderivaten und den entsprechenden Alkenen, Alkinen und Carbenen, wobei jede Verbindungsklasse anhand ihrer Synthese, ihrer Reaktivität und ihres Koordinationstyps kurz vorgestellt wird. Des Weiteren werden besondere Elektronenkonfigurationen der Phosphorverbindungen behandelt, darunter P‐P‐Einelektronenbindungen, gespannte Bindungen und aromatische Systeme. Abschließend wird auf mögliche Anwendungen dieser Chemie zur Herstellung molekularer Materialien und in der homogenen Katalyse verwiesen.

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“…Despite the striking analogies between the cyclopentaphosphide ion P 5 − and the ubiquitous cyclopentadienyl ligand and its complexes [Cp*( η 5 ‐P 5 ) Fe]3 and ferrocene it should not be overlooked that according to quantum chemical calculations the species “FeP 10 ”4 has nothing in common with the familiar class of ferrocenes or oligophosphaferrocenes. Recently it was pointed out by Zenneck et al that the introduction of six phosphorus atoms into a manganocene skeleton affords a low‐spin sandwich complex with an electronic structure different to that of decamethylmanganocene, and consistently the authors stated, that an analogy between P and C is no longer given, if formally analogous compounds differ significantly in their reactivities, spectra or molecular structures 5. Accordingly, the olefin‐like behavior of the phosphaalkenes crucially depends on the polarity (P δ + C δ − ) of the P=C double bond as anticipated by Pauling's electronegativies.…”

Section: Introductionmentioning

confidence: 99%

Reactivity of the Inversely Polarized Phosphaalkenes RP=C(NMe2)2 (R=tBu, Me3Si, H) towards Arylcarbene Complexes [(CO)5M=C(OEt)Ar] (Ar=Ph, M=Cr, W; Ar=2-MeC6H4, 2-MeOC6H4, M=W)

et al. 2001

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The reaction of the arylated Fischer carbene complexes [(CO)5M=C(OEt)Ar] (Ar=Ph; M = Cr, W; 2-MeC6H4; 2-MeOC6H; M = W) with the phosphaalkenes RP=C(NMe2), (R=tBu, SiMe3) afforded the novel phosphaalkene complexes [[RP=C(OEt)Ar]M(CO)5] in addition to the compounds [(RP=C(NMe2)2]M(CO)5]. Only in the case of the R = SiMe3 (E/Z) mixtures of the metathesis products were obtained. The bis(dimethylamino)methylene unit of the phosphaalkene precursor was incorporated in olefins of the type (Me2N)2C=C(OEt)(Ar). Treatment of [(CO)5W=C(OEt)(2-MeOC6H4)] with HP=C(NMe2)2 gave rise to the formation of an E/Z mixture of [[(Me2N)2CH-P=C(OEt)(2-MeOC6H4)]W(CO)5] the organophosphorus ligand of which formally results from a combination of the carbene ligand and the phosphanediyl [P-CH(NMe2)2]. The reactions reported here strongly depend on an inverse distribution of alpha-electron density in the phosphaalkene precursors (Pdelta Cdelta+), which renders these molecules powerfu] nucleophiles.

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P6-Manganocen und P3-Cymantren: Konsequenzen des Einbaus von Phosphoratomen in Mn-koordinierende Cyclopentadienyl-Liganden

Cited by 12 publications

References 19 publications

Selective Preparation of the [3,5‐tBu₂‐1,2,4‐C₂P₃]⁻ Ion and Synthesis and Structure of the Cationic Species nido‐[3,5‐tBu₂‐1,2,4‐C₂P₃]⁺, Isoelectronic with [C₅R₅]⁺

Selective Preparation of the [3,5‐tBu₂‐1,2,4‐C₂P₃]⁻ Ion and Synthesis and Structure of the Cationic Species nido‐[3,5‐tBu₂‐1,2,4‐C₂P₃]⁺, Isoelectronic with [C₅R₅]⁺

Phosphaorganische Chemie: Panorama und Perspektiven

Reactivity of the Inversely Polarized Phosphaalkenes RP=C(NMe2)2 (R=tBu, Me3Si, H) towards Arylcarbene Complexes [(CO)5M=C(OEt)Ar] (Ar=Ph, M=Cr, W; Ar=2-MeC6H4, 2-MeOC6H4, M=W)

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P6-Manganocen und P3-Cymantren: Konsequenzen des Einbaus von Phosphoratomen in Mn-koordinierende Cyclopentadienyl-Liganden

Cited by 12 publications

References 19 publications

Selective Preparation of the [3,5‐tBu2‐1,2,4‐C2P3]− Ion and Synthesis and Structure of the Cationic Species nido‐[3,5‐tBu2‐1,2,4‐C2P3]+, Isoelectronic with [C5R5]+

Selective Preparation of the [3,5‐tBu2‐1,2,4‐C2P3]− Ion and Synthesis and Structure of the Cationic Species nido‐[3,5‐tBu2‐1,2,4‐C2P3]+, Isoelectronic with [C5R5]+

Phosphaorganische Chemie: Panorama und Perspektiven

Reactivity of the Inversely Polarized Phosphaalkenes RP=C(NMe2)2 (R=tBu, Me3Si, H) towards Arylcarbene Complexes [(CO)5M=C(OEt)Ar] (Ar=Ph, M=Cr, W; Ar=2-MeC6H4, 2-MeOC6H4, M=W)

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Selective Preparation of the [3,5‐tBu₂‐1,2,4‐C₂P₃]⁻ Ion and Synthesis and Structure of the Cationic Species nido‐[3,5‐tBu₂‐1,2,4‐C₂P₃]⁺, Isoelectronic with [C₅R₅]⁺

Selective Preparation of the [3,5‐tBu₂‐1,2,4‐C₂P₃]⁻ Ion and Synthesis and Structure of the Cationic Species nido‐[3,5‐tBu₂‐1,2,4‐C₂P₃]⁺, Isoelectronic with [C₅R₅]⁺