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[iPr2P]2P? SiMe3 and [iPr2P]2PLi – Synthesis and Reactions Structure of [iPr2P]2P? P[PiPr2]2 [iPr2P]2P? SiMe3 1 and [iPr2P]2PLi 2 were prepared to investigate the influence of the bulky alkyl groups on formation and properties of the ylides R2P? P?P(X)R2 (R = iPr, tBu; X = Br, Me) in reactions of 1 with CBr4 and of 2 with 1,2-dibromoethane or MeCl, resp. Compared to the iPr groups the tBu groups favour the formation of ylides. With CBr4 1 forms iPr2P? P?P(Br)iPr2 5 just as a minor product which decomposes already below ?30°C. With 1,2-dibromoethane 2 yields only traces of 5 but [iPr2P]P? P[P(iPr)2]2 7 as main product. With MeCl 2 gives iPrP? P?P(Me)iPr2 9 and [iPr2P]2PMe 10 in a molar ratio of 1:1. 9 is considerably more stable than 5. 7 crystallizes triclinic in the space group P1 (No. 2) with a = 10.813 Å, b = 11.967 Å, c = 15.362 Å, α = 67.90°, β = 71.36°, γ = 64.11° and two formula units in the unit cell.  相似文献   

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Highly strained methylenephosphiranes are formed in the reaction of the new electrophilic phosphinidene complex [iPr2N−P=Fe(CO)4] with allenes. Remarkably, reaction with diallenes at 0°C also leads to a phosphirane, which rearranges upon warming to room temperature to a bis-isopropylidenephospholene (see scheme).  相似文献   

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Transition Metal Complexes of P-rich Phosphanes and Silylphosphanes. VII Carbonyl Complexes of the Heptaphosphane(3) iPr2(Me3Si)P7 From the reaction of iPr2(Me3Si)P7 1 with one equivalent of Cr(CO)5THF the yellow products iPr2(H)P7[Cr(CO)5] 2 and iPr2(Me3Si)P7[Cr(CO)5] 3 were isolated by column chromatography on silicagel. The P? H group in 2 results from a cleavage of the P? SiMe3 bond during chromatography. The Cr(CO)5 group in 2 is linked to an iPr? Pe atom, in 3 to the Me3Si? Pe atom of the P7 skeleton. The substituents do not force the formation of a single isomer; nevertheless 3 ist considerably favoured as compared to 2 . From the reaction of 1 with 2 equivalents of Cr(CO)5THF the yellow iPr2(H)P7[Cr(CO)5]2 4 was isolated bearing one Cr(CO)5 group at an iPr? Pe atom, the other one at a Pb atom of the P7 skeleton. Compound 3 yields with Cr(CO)4NBD the red iPr2(Me3Si)P7[Cr(CO)5][Cr(CO)4] 5 . Three isomers of 5 appear. Two Pe atoms of 5 are bridged by the Cr(CO)4 group, the third Pe atom is linked to the Cr(CO)5 ligand. iPr2(H)P7[Fe(CO)4] was isolated from the reaction of 1 with Fe2(CO)9. 31P NMR and MS data are reported.  相似文献   

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The T-shaped Pt(II) complex [PtMe(iPr3P)2][1-H-closo-CB11Me11], which is stabilised by an agostic interaction, undergoes acid-catalysed intramolecular C-H activation in the presence of THF to afford cyclometallated [Pt(THF)(iPr3P)(iPr2PCHMeCH2)][1-H-closo-CB11Me11].  相似文献   

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The reactions between chalcogen tetrahalides (ChX(4); Ch = Se, Te; X = Cl, Br) and the neutral donors (n)Bu(3)P, Ph(3)P, or the N-heterocyclic carbene, 2,5-diisopropylimidazole-2-ylidene ((i)Pr(2)IM), have been investigated. In cases involving a phosphine, the chemistry can be understood in terms of a succession of two-electron redox reactions, resulting in reduction of the chalcogen center (e.g., Se(IV) --> Se(II)) and the oxidation of phosphorus to the [R(3)P-X] cation (P(III) --> P(V)). The stepwise reduction of Se(IV) --> Se(II) --> Se(0) --> Se(-II) occurs upon the successive addition of stoichiometric equivalents of Ph(3)P to SeCl(4), which can readily be monitored by 31P{(1)H} NMR spectroscopy. In the case of reacting SeX(4) with (i)Pr(2)IM, a similar two-electron reduction of the chalcogen is observed and there is the concomitant production of a haloimidazolium hexahaloselenate salt. The products have been comprehensively characterized, and the solid-state structures of [R(3)PX][SeX(3)] (9), [Ph(3)PCl](2)[TeCl(6)] (10), (i)Pr(2)IM-SeX(2) (11), and [(i)Pr(2)IM-Cl](2)[SeCl(6)] (12) have been determined by X-ray diffraction analysis. These data all support two electron redox reactions and can be considered in terms of the formal reductive elimination of X2, which is sequestered by the Lewis base.  相似文献   

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The addition of HSiMe2Cl to the unsaturated compound Cp*(iPr3P)RuCl gives an unstable adduct which, according to NMR (J(H-Si)= 33.5 Hz), X-ray crystal structure and DFT evidence, is a silane sigma-complex Cp*(iPr3P)Ru(Cl)(eta2-HSiMe2Cl) supported by an unprecedented, simultaneous inter-ligand RuCl...SiCl hypervalent interaction between the chloride ligand on ruthenium and the SiMe2Cl group.  相似文献   

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Treatment of [(iPr3P)2Rh(nbd)][Y] {nbd = norbornadiene, Y = B{3,5-(CF3)2C6H3}4- [B(ArF)4] or 1-H-closo-CB11Me11-} with H2 (ca. 4 atm) results in the isolation, in moderate yield, of the octahedral cluster complex [(iPr3P)6Rh6H12][Y]2 1. The cluster (for both anions) has been characterized by NMR, mass spectroscopy, and X-ray crystallography. These show 1 to have 12 edge-bridging hydrogen atoms, and the structure bears more resemblance to clusters of the early transition metals with pi-donor ligands than those of the late transition metals with pi-acceptor ligands. Intermediate complexes on the route to 1, namely, the nonclassical dihydrogen complexes [(iPr3P)2Rh(H)2(eta2-H2)x][B(ArF)4] (x = 1 or 2), have been observed spectroscopically. The high hydride content of 1 makes it a possible model for nanocluster colloidal Rh(0) catalysts that are used in olefin and arene hydrogenation.  相似文献   

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The reaction of iPr2Si(PH2)2 ( 1 ) with [Ca{N(SiMe3)2}2(THF)2] at 25 °C in molar ratio 1:1 yields the compound [Ca3{iPr2Si(PH)2}3(THF)6] ( 2 ). Compound 2 consists of two Ca2P3 trigonal bipyramids with one conjoint calcium corner and SiiPr2 bridged phosphorus atoms. In contrast, the same reaction at 60 °C yield the complex [Ca({P(SiiPr2)2PH}2(THF)4] ( 3 ). The isotype strontium compound [Sr({P(SiiPr2)2PH}2(THF)4] ( 4 ) was obtained from the reaction of iPr2Si(PH2)2 with [Sr{N(SiMe3)2}2(DME)2]. The Compounds 2 – 4 were characterised by single crystal X‐ray diffraction, elemental analysis as well as IR and NMR spectroscopic techniques.  相似文献   

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The Phosphides LiR2P7, Li2RP7 (R = Me3Si, Et, iPr, iBu) as well as Mixed Alkylated and Silylated Heptaphosphanes(3) Formation and properties of LiR2P7 and Li2PR7 (R = Me3Si, Et, iPr, iBu) and their reactions with Me3SiCl or alkylhalides yielding mixed alkylated and silylated heptaphosphanes(3) are reported. Reactions of (Me3Si)3P7 and Li3P7. 3 DME produce mixtures of Li(Me3Si)3P7, Li2(Me3Si)P7 and Li3P7 from which pure Li(Me3Si)2P7 (s, as) can be isolated by means of an extraction with toluene. Similarly, the isomers of LiR2P7 (R = Et, iPr, iBu) can be extracted from the mixtures obtained by reacting Li3P7 with alkylbromides. The (s) isomers of LiR2P7 in solution at about 20°C from the (as) isomers whereas the latter up to 70°C do not show any inversion. The (as) lithiumdialkylphosphides can be obtained as ether free products (red brown powder, isoluble in toluene, soluble in THF) by repeated addition of toluene and removal of the solvents; the (s) isomers decompose during the procure. In reactions of LiEt2P7. THF (s, as) in toluene at ?30°C with EtBr only the (s) isomer is substituted and gives Et3P7 (s), however on warming to 20°C by inversion of Pe a ratio of (s) : (as( = 1 : 3 is obtained. With Li(iBu)2P7, (s) reaction begins above ?20°C the giving both the (s) and the (as) isomer. (iBu)3P7 (s) is the prefered isomer at higher temperatures. Li(Me3Si)2P7 (s, as) with Me3SiCl exclusively yields (Me3Si)3P7 (s). Li2RP7 (R = alkyl, Me3SI) is not available. From mixtures with LiR2P7 and Li3P7, it can be isolated only after repeated cumbersome extraction of LiR2P7 as was shown with Li2(iPr)P7 as an example. Ether free LiEt2P7(s, as) with Me3SiCl exclusively gives Et2(Me3Si)P7 (s, as) whereas LiEt2P7 ? THF due to its THF content does not. Similarly, ether free Li(iBu)2P7 yields (iBu)2(Me3Si)P7 (s, as). The compounds R(Me3Si)2P7 (R = alkyl) cannot be selectively prepared neither starting from Li2RP7 with Me3SiCI) nor from Li(Me3Si)2P7 with RX. Such, the reaction of Li(Me3Si)2P7 ? THF with EtBr in toluene at ?78°C yield a mixture of Et(Me3Si)2P7 (42%), Et2(Me3Si)P7 (27010), (Me3Si)3P7 (29%) and Et3P7 (2%). (Me3Si)3P7 with MeI in a molar ratio of 1 : 1 at 70°C quantitatively produces Me(Me3Si)2P7 whereas already using a molar ratio of 1 : 2 also Me3P7 is obtained. With EtBr mixtures of Et(Me3Si)2P7 and Et3P7 are formed. iBuBr gives iBu3P7, but tBuBr does not yield any tBu3P7.  相似文献   

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With six different metallocenes, namely iPr[CpFlu]ZrCl2 I , iPr[3‐MeCpFlu]ZrCl2 II , iPr[3‐EtCpFlu]ZrCl2 III , iPr[3‐iPrCpFlu]ZrCl2 IV , iPr[IndFlu]ZrCl2 V and iPr[3‐tBuCpFlu]ZrCl2 VI propene polymerizations were carried out at different polymerization temperatures. MAO was used as a cocatalyst for all polymerizations. In case of metallocenes II, III and IV an increase in isotacticity with increasing polymerization temperature was observed. This is due to the increased rotation and, as a consequence, to the increased steric demand of the substituent at the cyclopentadienyl residue. With metallocene V a catalyst of in principle the same type was synthesized, but rotation of the substituent is not possible. Here, in the contrary, the assumed effect was observed, that the stereospecificity of the metallocene decreases, while raising the polymerization temperature. In metallocene I there is no rotatory substituent at the cyclopentadienyl residue and therefore a more stereoirregular polymer is formed at higher polymerization temperatures. Metallocene VI produces poly(propylene) with slightly increased isotacticity at higher polymerization temperature.  相似文献   

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