Syntheses and structure of bis(pentamethylcyclopentadienyl)dithiophosphinato complexes

Bis(pentamethylcyclopentadienyl)phosphane Cp*2PH reacts with sulfur under basic conditions to give the corresponding dithiophosphinate salts M+ CP*2PS−2 (5 M+ = HNEt+3, 6 M+ = Li+), which are formed via the intermediate CP*2P(S)H (4). Both salts on treatment with cobalt(II) chloride give rise to the transition metal dithiophosphinate 7. The structures of this new type of diorganodithiophosphinate complexes in the solid state have been investigated. © 1997 John Wiley & Sons, Inc. Heteroatom Chem 8: 521–525, 1997

Ferrocenylbis(ylene) phosphoranes

The ferrocenylbis(methylene)phosphorane Fc-P(=CTms 2 ) 2 ( 1 ) (Fc = −C 5 H 4 FeC 5 H 5 ) can be synthesized starting from ferrocenyldichlorophosphane FcPCl 2 or ferrocenyldilithiophosphane FcPLl 2 . The X-ray structure of ( 1 ) shows some unusual structural features, which indicate considerable electronic interaction of the ferrocenyl group and the σ 3 λ 5 -phosphorane unit. As a consequence of this interaction, the rotational barrier of the methylene bonds is extraordinary low. Therefore, in contrast to other bis(methylene)phosphoranes, the endo - and exo -Tms groups are indistinguishable on the NMR time scale even at −100°C. The analogous ferrocenylbis(imino)phosphorane Fc-P(=NTms) 2 ( 9…

Ein PH-funktionalisiertes Polyphosphazen: ein Makromolekül mit hochflexiblem Grundgerüst

Bis(pentamethylcyclopentadienyl)-Substituted Phosphanes: Synthesis and Structure

The bis(1,2,3,4,5-pentamethyl-1,3-cyclopentadien-1-yl)phosphanes 3−7 are formed in good yields by the reaction of the halogenophosphanes 2a or 2b with the appropriate nucleophile. Following another route, the dialkylaminobis(pentamethylcyclopentadienyl)phosphanes 11a−c have been synthesized by the treatment of dichloro(dialkylamino)phosphanes with two equivalents of (pentamethylcyclopentadienyl)lithium. The compounds 3−11 have been characterized by multinuclear NMR spectroscopy and 3, 5, 6, and 11a have also been characterized by single-crystal X-ray diffraction studies. The molecular structure of 11a is governed by steric congestion, which typically would lead to a parallel arrangement of …

Synthesis and reactivity of P-ferrocenylalkylidenephosphanes and related iminophosphanes and diphosphenes

P-Ferrocenyl-substituted alkylidenephosphanes have been prepared and characterized spectroscopically. Their ready conversion to the corresponding acylphosphanes and 1,2-diacyldiphosphanes, as well as a new type of phosphirene synthesis are presented. The X-ray structure of the tetraferrocenyl-substituted diacyldiphosphane has been investigated. Furthermore, P-ferrocenyl iminophosphanes and their complexation behaviour are described. Diferrocenyldiphosphene, which is known to be unstable, has been stabilized by complexation; this has been confirmed by NMR-spectroscopy and X-ray structure analysis.

A PH-functionalized polyphosphazene: a macromolecule with a highly flexible backbone.

Syntheses and reactivity of aminobis(diorganylamino)phosphanes

Aminobis(diorganylamino)phosphanes (R2N)2PNH2 (R = iPr, c-Hex, Ph) (2a–c), were obtained by treatment of the corresponding chlorobis(diorganylamino)phosphanes 1a–c with lithium amide in liquid ammonia. The transition metal phosphane complex (R2N)2(H2N)PNi(CO)3 (3) was prepared by reaction of 2a with tetracarbonylnickel. N-Complexation of 2a with trimethylalane affords the iminophosphorane-alane adduct (R2N)2HP=N(H)AlMe3 (4) by 1,2-H shift from the nitrogen to the phosphorus atom. The corresponding reaction with aluminium trichloride leads to the formation of the salt [(R2N)2HP=N(H)]2AlC12+[AlC14]− (5), in which two iminophosphorane moieties are linked by an AlCl2 bridge. Lithiation of 2a an…

Novel [6]- and [7]Helicene-Like Quinones via Mono- and Bidirectional Chromium-Templated Benzannulation of Bridged Binaphthyl Carbene Complexes

A new organometallic approach to novel, functionalised, helicene-like quinones and bisquinones has been developed based on the chromium-templated [3+2+1] benzannulation reaction. The [5]helicene-analogous monocarbene chromium complexes 4, 5, 17 and 19, derived from dibromo-substituted methylene- or silylene-tethered binaphthols 2 and 3, react with various alkynes to give [6]helicene-like quinones 6–13 and 20–29 after oxidative work-up. A rare competition of angular vs. linear annulation is observed for the incorporation of phenylacetylene that affords quinones 21/22 and 28/29. Protection of the phenolic benzannulation product with camphanic acid chloride 14, followed by chromatographic sepa…

Island Homoaromaticity in the W-Shaped 2,4-Diphospha-3-arsapentadienide Anion and Related Compounds - Theoretical and Experimental Investigations

A series of anions with general formula (R2C=P)2Pn– (Pn = N, P, As, Sb; R = H, Me, CF3, SiH3, SiMe3, SiF3) was investigated theoretically at the DFT (RI-BP86/TZVP) and RI-MP2/TZVP levels of approximation. Significantly sharpened central PPnP bond angles were predicted for the species with π-acceptor R substituents. The corresponding bond angle values decrease in the order Pn = N >> P > As > Sb. This finding is in agreement with the previously published structural data for [(Me3Si)2C=P]2P–. An island homoaromaticity was proposed as a suitable explanation for the observed effect. In more detail, it consists of shifting negative charge to the electron-withdrawing terminal groups with formation…