Neuartige Arsaalkene aus einem Arsasilenderivat und Isocyaniden

Reaction of (η5-C5Me5)(CO)2FeP(SiMe3)2 (4a) with carbon disulfide afforded the unstable metallophosphaalkene (η5-C5Me5)(CO)2Fe−PC[SSiMe3]2 (5a), which decomposed to the doubly metalated 1,3,4-thiadiphosphole 8a by extrusion of bis(trimethylsilyl)sulfide. The transient metallophosphaalkene 5a was intercepted as the isolable [(CO)5Cr]-adduct 6a by treatment with [(Z)-cyclooctene]Cr(CO)5. Similarly, the metallodisilylarsanes (η5-C5Me5)(CO)2M−As(SiMe3)2 (M = Fe, Ru) (11a,b) were converted to stable metalloarsaalkenes 12a,b by exposure to CS2. Pentacarbonylchromium complexes 13a,b were accessible by reaction with [(Z)-cyclooctene]Cr(CO)5. The X-ray structure analysis of 13a revealed the molecule as the first η1-arsaalkene complex.

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“…The bond distance As(1)−C(18) (1.800(5) Å) is close to the theoretical value of 1.79 Å calculated for HAsCH 2 to 1.921(3) Å in cyclic 16 .…”

Section: Resultssupporting

confidence: 84%

Transition-Metal-Substituted Acyl Phosphanes and Phosphaalkenes. 33.¹ Transition-Metal-Substituted Arsaalkenes. 3.² Reactivity of Metallodisilylphosphanes and -arsanes (η⁵-C₅Me₅)(CO)₂M−E(SiMe₃)₂ (M = Fe, Ru; E = P, As) toward Carbon Disulfide. Formation of Metallophosphaalkenes, Metalloarsaalkenes, and 1,3,4-Thiadiphospholes

et al. 1997

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“…Indeed, we note that when the electron-releasing ability of the imidazole ring is further enhanced, the phosphorus chemical shift moves to even higher fields for similar carbenephosphinidene adducts (cf. 31 P δ -53.5 for 4). 13 Compounds 4, 13 5, 29 6, 29 7, 30 and 8 30 represent other examples of strongly polarized "phosphaalkenes" that have been reported.…”

Section: Discussionmentioning

confidence: 96%

“…Indeed, the 31 P chemical shifts reported for 5 and 6 are δ 28.6 and δ 69.5, respectively, consistent with these expectations. 29 The "phosphaalkenes" 7 and 8 appear to violate the trend between 31 P chemical shift and electron-releasing ability of the "ylidene" moiety. Both 7 and 8 show strongly shielded 31 P resonances (δ-133 and -38, respectively).…”

Section: Discussionmentioning

confidence: 99%

Carbene−Pnictinidene Adducts

et al. 1997

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The syntheses, characterizations, and X-ray crystallographic structure determinations are described for adducts of stable nucleophilic carbenes with pnictinidenes. The adducts between 1,3-dimesitylimidazol-2-ylidene and phenylphosphinidene, phenylarsinidene, (trifluoromethyl)phosphinidene, and (pentafluorophenyl)arsinidene are reported. These carbene-pnictinidene adducts are formed by the direct reaction of a stable nucleophilic carbene with the corresponding pnictinidene cyclic oligomers. The synthesis and structure of the adduct between 1,3-dimesitylimidazolin-2-ylidene and phenylphosphinidene from the reaction of 1,3-dimesitylimidazolin-2-ylidene with phenylphosphorus dichloride are also reported. These carbene-pnictinidene adducts possess strongly polarized pnictinidene-carbene bonds. The C-Pn-C angles are all typically small at 97-102 degrees, and there is only a 4% shortening of the nominal Pn=C double bond compared to the Pn-C single bond to the second substituent on the pnictogen. The (31)P NMR shifts of the phosphorus adducts suggest strongly shielded phosphorus centers in accord with the polarized structures.

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unclassified

Reaktive E=C (p-p)π-Systeme, XL. / Reactive E=C(p-p)π Systems, XL.

Albers

Grobe

Van

et al. 1995

Zeitschrift Für Naturforschung B

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Im Gegensatz zu den zahlreich bekannten Phosphaalkenen [2] wurden acyclische Arsaalkene (Alkylidenarsane) bisher nur in geringer Zahl be schrieben [3][4][5][6][7][8][9]. Ursache dafür ist die hohe R eak tivität der thermodynamisch besonders ungünsti gen AsC-Doppelbindung. Das einzige bisher be schriebene halogensubstituierte Derivat ist das kurzlebige Perfluor-2 -arsapropen F3CAs=CF2 (1), das 1984 durch Thermolyse von M e3SnAs(CF3 ) 2 nach Gl. (1) erzeugt und spektroskopisch (NMR, MS) charaktersiert wurde [10,11]. Ergebnisse und Diskussion Synthese und spektroskopische UntersuchungUnsere U ntersuchungen an Fluorphosphaalkenen [13, 14] haben gezeigt, daß Vertreter des Typs F 3 C P=C(X )N R 2 (X = F, O R ) in einfacher Weise durch Umsetzung PH-funktioneller Trifluormethylphosphane mit sekundären Aminen zugäng lich sind. Es lag deshalb nahe, dieses Synthesever fahren auf die Darstellung der homologen Arsen verbindungen zu übertragen.Setzt man Bis(trifluorm ethyl)arsan HAs(CF3) 2 (2) bei tiefen Tem peraturen in E ther oder Chloro form im Molverhältnis 1:3 mit Dimethylamin um, so setzt bei -6 0 °C unter Gelbfärbung der Lösung eine exotherm e Reaktion ein. Das gewünschte 0932-0776/95/0100-0094 $06.00

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Neuartige Arsaalkene aus einem Arsasilenderivat und Isocyaniden

Cited by 27 publications

References 18 publications

Carbene−Pnictinidene Adducts

Reaktive E=C (p-p)π-Systeme, XL. / Reactive E=C(p-p)π Systems, XL.

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