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1.
The reaction of [Pt(PCy3)2] with Br2B‐CH(SiMe3)2 resulted in generation of the first alkylideneboryl complex, trans‐[Br(Cy3P)2Pt{B?CH(SiMe3)}], with concomitant elimination of Me3SiBr. The trans bromide ligand of the alkylideneboryl complex was readily substituted by a methyl group upon treatment with methyllithium, leading to another alkylideneboryl complex, trans‐[Me(Cy3P)2Pt{B?CH(SiMe3)}]. Various spectrochemical techniques, single‐crystal X‐ray crystallography, and quantum chemical calculations confirmed the formulation of a double bond between the boron and the carbon atom. The theoretical studies also provided evidence for the stronger trans influence of the alkylideneboryl ligand over iminoboryl and oxoboryl ligands.  相似文献   

2.
A stable trans‐(alkyl)(boryl) platinum complex trans‐[Pt(BCat′)Me(PCy3)2] (Cat′=Cat‐4‐tBu; Cy=cyclohexyl=C6H11) was synthesised by salt metathesis reaction of trans‐[Pt(BCat′)Br(PCy3)2] with LiMe and was fully characterised. Investigation of the reactivity of the title compound showed complete reductive elimination of Cat′BMe at 80 °C within four weeks. This process may be accelerated by the addition of a variety of alkynes, thereby leading to the formation of the corresponding η2‐alkyne platinum complexes, of which [Pt(η2‐MeCCMe)(PCy3)2] was characterised by X‐ray crystallography. Conversion of the trans‐configured title compound to a cis derivative remained unsuccessful due to an instantaneous reductive elimination process during the reaction with chelating phosphines. Treatment of trans‐[Pt(BCat′)Me(PCy3)2] with Cat2B2 led to the formation of CatBMe and Cat′BMe. In the course of further investigations into this reaction, indications for two indistinguishable reaction mechanisms were found: 1) associative formation of a six‐coordinate platinum centre prior to reductive elimination and 2) σ‐bond metathesis of B? B and C? Pt bonds. Mechanism 1 provides a straightforward explanation for the formation of both methylboranes. Scrambling of diboranes(4) Cat2B2 and Cat′2B2 in the presence of [Pt(PCy3)2], fully reductive elimination of CatBMe or Cat′BMe from trans‐[Pt(BCat′)Me(PCy3)2] in the presence of sub‐stoichiometric amounts of Cat2B2, and evidence for the reversibility of the oxidative addition of Cat2B2 to [Pt(PCy3)2] all support mechanism 2, which consists of sequential equilibria reactions. Furthermore, the solid‐state molecular structure of cis‐[Pt(BCat)2(PCy3)2] and cis‐[Pt(BCat′)2(PCy3)2] were investigated. The remarkably short B? B separations in both bis(boryl) complexes suggest that the two boryl ligands in each case are more loosely bound to the PtII centre than in related bis(boryl) species.  相似文献   

3.
A series of NCO/NCS pincer precursors, 3‐(Ar2OCH2)‐2‐Br‐(Ar1N?CH)C6H3 ((Ar1NCOAr2)Br, 3a , 3b , 3c , 3d ) and 3‐(2,6‐Me2C6H3SCH2)‐2‐Br‐(Ar1N?CH)C6H3 ((Ar1NCSMe)Br, 4a and 4b ) were synthesized and characterized. The reactions of [Ar1NCOAr2]Br/ [Ar1NCSMe]Br with nBuLi and the subsequent addition of the rare‐earth‐metal chlorides afforded their corresponding rare‐earth‐metal–pincer complexes, that is, [(Ar1NCOAr2)YCl2(thf)2] ( 5a , 5b , 5c , 5d ), [(Ar1NCOAr2)LuCl2(thf)2] ( 6a , 6d ), [(Ar1NCOAr2)GdCl2(thf)2] ( 7 ), [{(Ar1NCSMe)Y(μ‐Cl)}2{(μ‐Cl)Li(thf)2(μ‐Cl)}2] ( 8 , 9 ), and [{(Ar1NCSMe)Gd(μ‐Cl)}2{(μ‐Cl)Li(thf)2(μ‐Cl)}2] ( 10 , 11 ). These diamagnetic complexes were characterized by 1H and 13C NMR spectroscopy and the molecular structures of compounds 5a , 6a , 7 , and 10 were well‐established by X‐ray diffraction analysis. In compounds 5a , 6a , and 7 , all of the metal centers adopted distorted pentagonal bipyramidal geometries with the NCO donors and two oxygen atoms from the coordinated THF molecules in equatorial positions and the two chlorine atoms in apical positions. Complex 10 is a dimer in which the two equal moieties are linked by two chlorine atoms and two Cl? Li? Cl bridges. In each part, the gadolinium atom adopts a distorted pentagonal bipyramidal geometry. Activated with alkylaluminum and borate, the gadolinium and yttrium complexes showed various activities towards the polymerization of isoprene, thereby affording highly cis‐1,4‐selective polyisoprene, whilst the NCO? lutetium complexes were inert under the same conditions.  相似文献   

4.
Three new (N‐diphenylphosphino)‐isopropylanilines, having isopropyl substituent at the carbon 2‐ (1) 4‐ (2) or 2,6‐ (3) were prepared from the aminolysis of chlorodiphenylphosphine with 2‐isopropylaniline, 4‐isopropylaniline or 2,6‐diisopropylaniline, respectively, under anaerobic conditions. Oxidation of 1,2 and 3 with aqueous hydrogen peroxide, elemental sulfur or gray selenium gave the corresponding oxides, sulfides and selenides (Ph2P?E)NH? C6H4? 2‐CH(CH3)2, (Ph2P?E)NH? C6H4? 4‐CH(CH3)2 and (Ph2P?E)NH? C6H4? 2,6‐{CH(CH3)2}2, where E = O, S, or Se, respectively. The reaction of [M(cod)Cl2] (M = Pd, Pt; cod = 1,5‐cyclooctadiene) with two equivalents of 1,2 or 3 yields the corresponding monodendate complexes [M((Ph2P)NH? C6H4? 2‐CH(CH3)2)2Cl2], M = Pd 1d, M = Pt 1e, [M((Ph2P)NH? C6H4? 4‐CH(CH3)2)2Cl2], M = Pd 2d, M = Pt 2e and [M((Ph2P)NH? C6H4? 2,6‐(CH(CH3)2)2)2Cl2], M = Pd 3d, M = Pt 3e, respectively. All the compounds were isolated as analytically pure substances and characterized by NMR, IR spectroscopy and elemental analysis. Furthermore, representative solid‐state structure of [(Ph2P?S)NH? C6H4? 4‐CH(CH3)2] (2b) was determined using single crystal X‐ray diffraction technique. The complexes 1d–3d were tested and found to be highly active catalysts in the Suzuki coupling and Heck reaction, affording biphenyls and stilbenes, respectively. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

5.
Ambient‐temperature photolysis of the aminoborylene complex [(OC)5Cr?B?N(SiMe3)2] in the presence of a series of trans‐bis(alkynyl)platinum(II) precursors of the type trans‐[Pt(CCAr)2(PEt3)2] (Ar=Ph, p‐C6H4OMe, and p‐C6H4CF3) successfully leads to twofold transfer of the borylene moiety [ : B?N(SiMe3)2] onto the alkyne functionalities. The alkynyl precursors and resultant bis(borirene)platinum(II) complexes formed are of the type trans‐[Pt(B{?N(SiMe3)2}C?CAr)2(PEt3)2] (Ar=Ph, p‐C6H4OMe, and p‐C6H4CF3). These species have all been successfully characterized by NMR, IR, and UV/Vis spectroscopy as well as by elemental analysis. Single‐crystal X‐ray diffraction has verified that these trans‐bis(borirene)platinum(II) complexes display coplanarity between the twin three‐membered rings across the platinum core in the solid state and stand as the first examples of coplanar conformations of twin borirene systems. These complexes were modeled using density functional theory (DFT), providing information helpful in determining the ability of the transition metal core to interact with each individual borirene ring system and allowing for the observed coplanarity of these rings in the solid state. This proposed transition metal interaction with the twin borirene systems is manifested in the electronic characterization of these borirene species, which display divergent photophysical UV/Vis spectroscopic profiles compared to a previously published mono(borirene)platinum(II) complex.  相似文献   

6.
Stabilization of the central atom in an oxidation state of zero through coordination of neutral ligands is a common bonding motif in transition‐metal chemistry. However, the stabilization of main‐group elements in an oxidation state of zero by neutral ligands is rare. Herein, we report that the transamination reaction of the DAMPY ligand system (DAMPY=2,6‐[ArNH‐CH2]2(NC5H3) (Ar=C6H3‐2,6‐iPr2)) with Sn[N(SiMe3)2]2 produces the DIMPYSn complex (DIMPY=(2,6‐[ArN?CH]2(NC5H3)) with the Sn atom in a formal oxidation state of zero. This is the first example of a tin compound stabilized in a formal oxidation state of zero by only one donor molecule. Furthermore, three related low‐valent SnII complexes, including a [DIMPYSnIICl]+[SnCl3]? ion pair, a bisstannylene DAMPY{SnII[N(SiMe3)2]2}2, and the enamine complex MeDIMPYSnII, were isolated. Experimental results and the conclusions drawn are also supported by theoretical studies at the density functional level of theory and 119Sn Mössbauer spectroscopy.  相似文献   

7.
Monocationic bis‐allyl complexes [Ln(η3‐C3H5)2(thf)3]+[B(C6X5)4]? (Ln=Y, La, Nd; X=H, F) and dicationic mono‐allyl complexes of yttrium and the early lanthanides [Ln(η3‐C3H5)(thf)6]2+[BPh4]2? (Ln=La, Nd) were prepared by protonolysis of the tris‐allyl complexes [Ln(η3‐C3H5)3(diox)] (Ln=Y, La, Ce, Pr, Nd, Sm; diox=1,4‐dioxane) isolated as a 1,4‐dioxane‐bridged dimer (Ln=Ce) or THF adducts [Ln(η3‐C3H5)3(thf)2] (Ln=Ce, Pr). Allyl abstraction from the neutral tris‐allyl complex by a Lewis acid, ER3 (Al(CH2SiMe3)3, BPh3) gave the ion pair [Ln(η3‐C3H5)2(thf)3]+[ER31‐CH2CH?CH2)]? (Ln=Y, La; ER3=Al(CH2SiMe3)3, BPh3). Benzophenone inserts into the La? Callyl bond of [La(η3‐C3H5)2(thf)3]+[BPh4]? to form the alkoxy complex [La{OCPh2(CH2CH?CH2)}2(thf)3]+[BPh4]?. The monocationic half‐sandwich complexes [Ln(η5‐C5Me4SiMe3)(η3‐C3H5)(thf)2]+[B(C6X5)4]? (Ln=Y, La; X=H, F) were synthesized from the neutral precursors [Ln(η5‐C5Me4SiMe3)(η3‐C3H5)2(thf)] by protonolysis. For 1,3‐butadiene polymerization catalysis, the yttrium‐based systems were more active than the corresponding lanthanum or neodymium homologues, giving polybutadiene with approximately 90 % 1,4‐cis stereoselectivity.  相似文献   

8.
Synthesis of a Functional Aluminium Alkynide, Me3C‐C≡C‐AlBr2, and its Reactions with the Bulky Lithium Compound LiCH(SiMe3)2 Treatment of aluminium tribromide with the lithium alkynide (Li)C≡C‐CMe3 afforded the aluminium alkynide Me3C‐C≡C‐AlBr2 ( 1 ) in an almost quantitative yield. 1 crystallizes with trimeric formula units possessing Al3C3 heterocycles and the anionic carbon atoms of the alkynido groups in the bridging positions. A dynamic equilibrium was determined in solution which probably comprises trimeric and dimeric formula units. Reaction of 1 with one equivalent of LiCH(SiMe3)2 yielded the compound [Me3C‐C≡C‐Al(Br)‐CH(SiMe3)2]2 ( 2 ), which is a dimer via Al‐C‐Al bridges. Two equivalents of the lithium compound gave a mixture of four main‐products, which could be identified as 2 , Li[Me3C‐C≡C‐Al{CH(SiMe3)2}3] ( 3 ), Me3C‐C≡C‐Al[CH(SiMe3)2]2 ( 4 ), and Al[CH(SiMe3)2]3. The lithium atom of 3 is coordinated by the C≡C triple bond and an inner carbon atom of one bis(trimethylsilyl)methyl group. Further interactions were observed to C‐H bonds of methyl groups.  相似文献   

9.
This paper describes the formation of new platinacyclic complexes derived from the phosphine ligands PiPr2Xyl, PMeXyl2, and PMe2Ar (Xyl=2,6‐Me2C6H3 and Ar=2,6‐(2,6‐Me2C6H3)2‐C6H3) as well as reactivity studies of the trans‐[Pt(C^P)2] bis‐metallacyclic complex 1 a derived from PiPr2Xyl. Protonation of compound 1 a with [H(OEt2)2][BArF] (BArF=B[3,5‐(CF3)2C6H3]4) forms a cationic δ‐agostic structure 4 a , whereas α‐hydride abstraction employing [Ph3C][PF6] produces a cationic platinum carbene trans‐[Pt{PiPr2(2,6‐CH(Me)C6H3}{PiPr2(2,6‐CH2(Me)C6H3}][PF6] ( 8 ). Compounds 4 a and 8 react with H2 to yield the same 1:3 equilibrium mixture of 4 a and trans‐[PtH(PiPr2Xyl)2][BArF] ( 6 ), in which one of the phosphine ligands participates in a δ‐agostic interaction. DFT calculations reveal that H2 activation by 8 occurs at the highly electrophilic alkylidene terminus with no participation of the metal. The two compounds 4 a and 8 experience C–C coupling reactions of a different nature. Thus, 4 a gives rise to complex trans‐[PtH{(E)‐1,2‐bis(2‐(PiPr2)‐3‐MeC6H3)CH?CH}] ( 7 ) that contains a tridentate diphosphine–alkene ligand, through agostic C?H oxidative cleavage and C–C reductive coupling steps, whereas the C–C coupling reaction in 8 involves classical migratory insertion of its [Pt?CH] and [Pt?CH2] bonds promoted by platinum coordination of CO or CNXyl. The mechanisms of the C?C bond‐forming reactions have also been investigated by computational methods.  相似文献   

10.
The potassium aluminyl complex K[Al(NONAr)] (NON=NONAr=[O(SiMe2NAr)2]2?, Ar=2,6‐iPr2C6H3) reacts with 1,3,5,7‐cyclooctatetraene (COT) to give K[Al(NONAr)(COT)]. The COT‐ligand is present in the asymmetric unit as a planar μ2‐η28‐bridge between Al and K, with additional K???π‐aryl interactions to neighboring molecules that generate a helical chain. DFT calculations indicate significant aromatic character, consistent with reduction to [COT]2?. Addition of 18‐crown‐6 causes a rearrangement of the C8‐carbocycle to form the isomeric 9‐aluminabicyclo[4.2.1]nona‐2,4,7‐triene anion.  相似文献   

11.
Self‐immobilized nickel and iron diimine catalysts bearing one or two allyl groups of [ArN?C]2(C10H6)NiBr2 [Ar = 4‐allyl‐2,6‐(i‐Pr)2C6H2] ( 1 ), [ArN?C(Me)][Ar′N? C(Me)]C5H3NFeCl2 [Ar = Ar′ = 4‐allyl‐2,6‐(i‐Pr)2C6H3, Ar = 2,6‐(i‐Pr)2C6H3, and Ar′ = 4‐allyl‐2,6‐(i‐Pr)2C6H3] were synthesized and characterized. All three catalysts were investigated for olefin polymerization. As a result, these catalysts not only showed high activities as the catalyst free from the allyl group, such as [ArN?C]2C10H6NiBr2 (Ar = 2,6‐(i‐Pr)2C6H2)], but also greatly improved the morphology of polymer particles to afford micron‐granula polyolefin. The self‐immobilization of catalysts, the formation mechanism of microspherical polymer, and the influence on the size of the particles are discussed. The molecular structure of self‐immobilized nickel catalyst 1 was also characterized by crystallographic analysis. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1018–1024, 2004  相似文献   

12.
An efficient two‐step synthesis of the first NHC‐stabilized disilavinylidene (Z)‐(SIdipp)SiSi(Br)Tbb ( 2 ; SIdipp=C[N(C6H3‐2,6‐iPr2)CH2]2, Tbb=C6H2‐2,6‐[CH(SiMe3)2]2‐4‐tBu, NHC=N‐heterocyclic carbene) is reported. The first step of the procedure involved a 2:1 reaction of SiBr2(SIdipp) with the 1,2‐dibromodisilene (E)‐Tbb(Br)SiSi(Br)Tbb at 100 °C, which afforded selectively an unprecedented NHC‐stabilized bromo(silyl)silylene, namely SiBr(SiBr2Tbb)(SIdipp) ( 1 ). Alternatively, compound 1 could be obtained from the 2:1 reaction of SiBr2(SIdipp) with LiTbb at low temperature. 1 was then selectively reduced with C8K to give the NHC‐stabilized disilavinylidene 2 . Both low‐valent silicon compounds were comprehensively characterized by X‐ray diffraction analysis, multinuclear NMR spectroscopy, and elemental analyses. Additionally, the electronic structure of 2 was studied by various quantum‐chemical methods.  相似文献   

13.
Treatment of β-diketiminate ligands bearing different N-aryl monoatomic substituents [HLH = (C6H5)N = C(Me)CH=C(Me)NH(C6H5), HLF = (2,6-F2C6H3)N=C(Me)CH=C(Me)NH(2,6-F2C6H3), and HLCl = (2,6-Cl2C6H3)N=C(Me)CH=C(Me)NH(2,6-Cl2C6H3)] with Ln(CH2SiMe3)3(THF)2 (Ln = Y and Lu) afforded a variety of β-diketiminato rare-earth metal complexes depending on substituents, namely, phenyl ring C–H bond activated complexes (L')(LH)Lu(THF) ( 1b , L' = (C6H4)N = C(Me)CH=C(Me)N(C6H5)), six-coordinate homoleptic complexes (LH)3Ln [Ln = Y ( 1aa ), Lu ( 1bb )], five-coordinate monoalkyl complexes (LF)2Ln(CH2SiMe3) [Ln = Y ( 2a ), Lu ( 2b )], and four-coordinate dialkyl complexes (LCl)Ln(CH2SiMe3)2 [Ln = Y ( 3a ), Lu ( 3b )]. All these complexes were characterized with NMR spectroscopy, and lutetium complexes 1b , 1bb and 3b were structurally validated by single-crystal X-ray diffraction analysis. Moreover, dialkyl complexes 3 promoted the polymerization of 2-vinylpyridine (2-VP) to produce atactic poly(2-vinylpyridine) (P2VP) with quantitative yield. On activation with an equimolar amount of [Ph3C][B(C6F5)4], complexes 3 afforded highly isotactic P2VP with an mm value up to 94 %. Both 1H NMR spectrum and MALDI-TOF mass analysis of an oligomer indicate that the polymerization was initiated by coordination insertion of 2-VP into the Y-CH2SiMe3 bond.  相似文献   

14.
The reaction of diaryldibromodigermene Tbb(Be)Ge = Ge(Br)Tbb (Tbb = 4-But-2,6-[CH(SiMe3)2]2C6H2) with N,N'-diisopropyl-carbodiimide afforded the corresponding amidinato-supported bromogermylene via the insertion of the C=N moiety into the Ge–C(Tbb) sss-bond. The formation mechanism of the amidinato-supported bromogermylene was revealed by DFT calculations. This type of insertion reaction toward a metal–carbon bond can be interpreted in analogy to the reactivity of transition-metal complexes.  相似文献   

15.
The reagent RK [R=CH(SiMe3)2 or N(SiMe3)2] was expected to react with the low‐valent (DIPPBDI)Al (DIPPBDI=HC[C(Me)N(DIPP)]2, DIPP=2,6‐iPr‐phenyl) to give [(DIPPBDI)AlR]?K+. However, deprotonation of the Me group in the ligand backbone was observed and [H2C=C(N‐DIPP)?C(H)=C(Me)?N?DIPP]Al?K+ ( 1 ) crystallized as a bright‐yellow product (73 %). Like most anionic AlI complexes, 1 forms a dimer in which formally negatively charged Al centers are bridged by K+ ions, showing strong K+???DIPP interactions. The rather short Al–K bonds [3.499(1)–3.588(1) Å] indicate tight bonding of the dimer. According to DOSY NMR analysis, 1 is dimeric in C6H6 and monomeric in THF, but slowly reacts with both solvents. In reaction with C6H6, two C?H bond activations are observed and a product with a para‐phenylene moiety was exclusively isolated. DFT calculations confirm that the Al center in 1 is more reactive than that in (DIPPBDI)Al. Calculations show that both AlI and K+ work in concert and determines the reactivity of 1 .  相似文献   

16.
A wide range of potential ligand precursors and related compounds have been synthesized from ferrocenyldibromoborane and ferrocenylenebis(dibromoborane) via salt elimination reactions. These comprise ligand precursors suitable for the preparation of (i) ansa‐metallocenes such as [FcB(η1‐C5H5)2] ( 2 ), [FcB(1‐C9H7)2] ( 3 ), [FcB(3‐C9H7)2] ( 4 ) and [1,1′‐fc{B(3‐C9H7)2}2] ( 11 ), (ii) constrained geometry complexes such as [FcB(1‐C9H7)N(H)Ph] ( 7 ) and [FcB(3‐C9H7)N(H)Ph] ( 8 ), (iii) ansa‐diamido complexes such as [FcB(N(H)Ph)2] ( 9 ) as well as (iv) the related compounds [FcB(Br)N(H)tBu] ( 5 ), [FcB(Br)N(H)Ph] ( 6 ), [1,1′‐fc{B(Br)N(SiMe3)2}2] ( 12 ) and [1,1′‐fc{B(Br)NiPr2}2] ( 13 ) (Fc = ferrocenyl, fc = ferrocenylene, C5H5 = cyclopentadienyl, C9H7 = indenyl). All new compounds have been characterised by multinuclear NMR spectroscopic techniques and in the case of 7 and 12 by X‐ray diffraction methods.  相似文献   

17.
A series of four, five and six‐coordinated magnesium derivatives integrating with substituted pyrrole and ketimine ligands are conveniently synthesized. Reaction of two equiv of 2‐dimethylaminomethyl pyrrole with Mg[N(SiMe3)2]2 in THF affords the monomeric magnesium complex Mg[C4H3N(2‐CH2NMe2)]2 (THF)2 ( 1 ) in high yield along with elimination of two equiv of HN(SiMe3)2. Similarly, the reaction between two equiv of 2‐t‐butylaminomethyl pyrrole and Mg[N(SiMe3)2]2 in THF renders the magnesium derivative, Mg[C4H3N(2‐CH2NHtBu)]2(THF)22( 2 ) in good yield. Interestingly, reaction between two equiv of 2‐t‐butylaminomethyl pyrrole and Mg[N(SiMe3)2]2 in toluene, instead of THF, generates Mg[C4H3N(2‐CH2NHtBu)]2 ( 3 ), also in high yield. Furthermore, the assembly of two equiv of ketimine ligand, HOCMeCHCMeNAr (Ar = C6H3‐2,6‐iPr2) and Mg[N(SiMe3)2]2, yields five‐coordinated magnesium derivatives, Mg(OCMeCHCMeNAr)2(THF) ( 4 ) and Mg(OCMeCHCMeNAr)2(OEt2) ( 5 ), using THF and diethyl ether, respectively. All the aforementioned derivatives are characterized by 1H and 13C NMR spectroscopy as well as 1 , 3 , 4 and 5 are subjected to X‐ray diffraction analysis in solid state.  相似文献   

18.
Treatment of the osmabenzene [Os{CHC(PPh3)CHC(PPh3)CH} Cl2(PPh3)2]Cl ( 1 ) with excess 8‐hydroxyquinoline produces monosubstituted osmabenzene [Os{CH C(PPh3) CHC(PPh3)CH}(C9H6NO)Cl(PPh3)]Cl ( 2 ) or disubstituted osmabenzene [Os{CHC(PPh3)CHC(PPh3)CH} (C9H6NO)2]Cl ( 3 ) under different reaction conditions. Osmabenzene 2 evolves into cyclic η2‐allene‐coordinated complex [Os{CH?C(PPh3)CH=(η2‐C?CH2)}(C9H6NO)(PPh3)2]Cl ( 4 ) in the presence of excess PPh3 and NaOH, presumably involving a P? C bond cleavage of the metallacycle. Reaction of 4 with excess 8‐hydroxyquinoline under air affords the SNAr product [(C9H6NO)Os{CHC(PPh3)CHCHC} (C9H6NO)(PPh3)]Cl ( 5 ). Complex 4 is fairly reactive to a nucleophile in the presence of acid, which could react with water to give carbonyl complex [Os{CH?C(PPh3)CH?CH2}(C9H6NO) (CO)(PPh3)2]Cl ( 6 ). Complex 4 also reacts with PPh3 in the presence of acid and results in a transformation to [Os {CHC(PPh3)CHCHC}(C9H6NO)Cl (PPh3)2]Cl ( 7 ) and [Os{CH?C(PPh3) CH=(η2‐C?CH(PPh3))}(C9H6NO) Cl(PPh3)]Cl ( 8 ). Further investigation shows that the ratio of 7 and 8 is highly dependent on the amount of the acid in the reaction.  相似文献   

19.
The metal complexes [Ni{N(Ar)C(R)C(H)Ph}2) ( 2 ) (Ar = 2,6‐Me2C6H3, R = SiMe3), [Ti(Cp2){N(R)C(But)C(H)R}] ( 3 ), M{N(R)C(But)C(H)R}I [M = Ni ( 4 a ) or Pd ( 4 b )] and [M{N(R)C(But)C(H)R}I(PPh3)] [M = Ni ( 5 a ) or Pd ( 5 b )] have been prepared from a suitable metal halide and lithium precursor of ( 2 ) or ( 3 ) or, alternatively from [M(LL)2] (M = Ni, LL = cod; M = Pd, LL = dba) and the ketimine RN = C(But)CH(I)R ( 1 ). All compounds, except 4 were fully characterised, including the provision of X‐ray crystallographic data for complex 5 a .  相似文献   

20.
The reactions of some cyclometallated azo and imino compounds have been studied. Treatment of [IrHX(PhCCHCHNC3H7)(PCy3)2] with X2 (X = Cl, Br) yields substitution products [IrHX(PhCCXCHNC3H7)(PCy3)2] without rupture of the IrC bond. Treatment of [IrHCl(5-CH3 · C6H3CHNCH3) (PPh3)2] with AgClO4 and then with CNC6H11 or CO (= L) leads to the formation of the complexes [IrHL(5-CH3 · C6H3CHNCH3)(PPh3)2]ClO4, the metallocyclic ring remaining intact. Rupture of the metallocyclic ring is observed when [PdCl(C6H4NNPh)]2 is treated under mild conditions with CNC6H11, and the insertion product [PdCl(CNC6H11)2 {(CNC6H11)2C6H4NNPh} ] is obtained.Possible mechanisms for the reactions are discussed.  相似文献   

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