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1.
The iridium dinitrogen complex [IrCl(N2)(PPh3)2] (1) was found to react with alkynylsilanes to form the vinylidene iridium(I) complexes trans- (R/R′ = Ph/Me, 2; Me/Me, 3; Bn/Me, 4; SiMe3/Me, 5; SiEt3/Et, 6; iPr/Me, 7) and with Me3SiCCC(O)R to yield the iridium η2-alkyne complexes trans-[IrCl{η2-Me3SiCCC(O)R}(PPh3)2] (R = OEt, 9; Me, 11). Complex 9 was found to isomerize upon heating or upon UV irradiation yielding the vinylidene complex trans-[IrCl{CC(SiMe3)CO2Et}(PPh3)2] (10). The reaction of 1 with Me3SiCCCCSiMe3 yielded the complex trans-[IrCl{CC(SiMe3)CCSiMe3}(PPh3)2] (8), whereas with MeO2CCCCO2Me the iridacyclopentadiene complex [Ir{C4(CO2Me)4}Cl(PPh3)2] (13) was formed. The complexes were characterized by means of 1H, 13C and 31P NMR spectroscopy as well as by IR spectroscopy and microanalysis.  相似文献   

2.
Ligand effects on the catalytic activity [and norbornene (NBE) incorporation] for both ethylene polymerization and ethylene/NBE copolymerization using half-titanocenes (titanium half-sandwich complexes) containing ketimide ligand of type Cp′TiCl2[NC(R1)R2] [Cp′ = Cp (1), C5Me5 (Cp, 2); R1,R2 = tBu,tBu (a), tBu,Ph (b), Ph,Ph (c)]-methylaluminoxane (MAO) catalyst systems have been investigated. CpTiCl2[NC(tBu)Ph] (1b) CpTiCl2(NCPh2) (1c), and CpTiCl2(NCPh2) (2c) were prepared and identified; the structure of CpTiCl2(NCPh2) (2c) was determined by X-ray crystallography. The catalytic activity for ethylene polymerization increased in the order: 1a > 1b > 1c, suggesting that an electronic nature of the ketimide ligand affects the activity. However, molecular weight distributions for resultant (co)polymers prepared by 1b,c and by 2c-MAO catalyst systems were bi- or multi-modal, suggesting that the ketimide substituent plays a key role in order for these (co)polymerizations to proceed with single catalytically-active species. CpTiCl2(NCtBu2) (1a) exhibited both remarkable catalytic activity and efficient NBE incorporation for ethylene/NBE copolymerization.  相似文献   

3.
A Mo(0) complex containing a new tetraphosphine ligand [Mo(P4)(dppe)] (1; P4 = meso-o-C6H4(PPhCH2CH2PPh2)2, dppe = Ph2PCH2CH2PPh2) reacted with CO2 (1 atm) at 60 °C in benzene to give a Mo(0) carbonyl complex fac-[Mo(CO)(η3-P4O)(dppe)] (2), where the O abstraction from CO2 by one terminal P atom in P4 takes place to give the dangling P(O)Ph2 moiety together with the coordinated CO. On the other hand, reaction of 1 with TolNCS (Tol = m-MeC6H4) in benzene at 60 °C resulted in the incorporation of three TolNCS molecules to the Mo center, forming a Mo(0) isocyanide-isothiocyanate complex trans,mer-[Mo(TolNC)22-TolNCS)(η3-P4S)] (4), where the S abstraction occurs from two TolNCS molecules by P4 and dppe to give the η3-P4S ligand and free dppeS, respectively, together with two coordinated TolNC molecules. The remaining site of the Mo center is occupied by the third TolNCS ligating at the CS bond in an η2-manner. The X-ray analysis has been undertaken to determine the detailed structures for 2 and 4.  相似文献   

4.
Bimetallic alkylidene complexes of tungsten (R′O)2(ArN)WCH-SiR2-CHW(NAr)(OR′)2 (R = Me (1), Ph (2)) and (R′O)2(ArN)WCH-SiMe2SiMe2-CHW(NAr)(OR′)2 (3) (Ar = ; R′ = CMe2CF3) have been prepared by the reactions of divinyl silicon reagents R2Si(CHCH2)2 with known alkylidene compounds R′′-CHMo(NAr)(OR′)2. (R′′ = But, PhMe2C) Complexes 1-3 were structurally characterized. Ring opening metathesis polymerization (ROMP) of cyclooctene using compounds 1-3 as initiators led to the formation of high molecular weight polyoctenamers with predominant trans-units content in the case of 1 and 3 and predominant cis-units content in the case of 2.  相似文献   

5.
The reaction of 1,1,4,4-tetrakis[bis(trimethylsilyl)methyl]-1,4-diisopropyltetrasila-2-yne 1 with secondary or primary amines produced amino-substituted disilenes R(R2′N)SiSiHR 2a-d (R = SiiPr[CH(SiMe3)2]2, R2′NEt2N (2a), (CH2CH2)2N (2b), tBu(H)N (2c), and Ph2N (2d)). Spectroscopic and X-ray crystallographic analyses of 2 showed that 2a-c have a nearly coplanar arrangement of the SiSi double bond and the amino group, giving π-conjugation between the SiSi double bond and the lone pair on the nitrogen atom, whereas 2d has a nearly perpendicular arrangement precluding such conjugation. Theoretical calculations indicate that π-conjugation between the π-orbital of the SiSi double bond and the lone pair on the nitrogen atom is markedly influenced by the torsional angle between the SiSi double-bond plane and the amino-group plane.  相似文献   

6.
The reaction of (Ph3P)3RuCl2 with 1,1-diphenyl-2-propyn-1-ol was investigated in various solvents. The reaction in thf under reflux is reported to produce the (PPh3)2Cl2Ru(3-phenylindenylidene) complex (3) which has undergone rearrangement of the allenylidene C3-spine. We have improved the reliability of the reported synthesis by adding acetyl chloride which converts the formed water of the reaction and thus increases the acidity of the reaction solution. Without the additive, we observed the exclusive formation of an intermediate of the transformation and identified it as dinuclear (PPh3)2ClRu(μ-Cl)3(PPh3)2RuCCCPh2 complex (5). The reaction of (Ph3P)3−4RuCl2 with 1,1-diphenyl-2-propyn-1-ol in CH2Cl2 or C2H4Cl2 under reflux in the presence of excess conc. aqueous HCl afforded the new, neutral (PPh3)2Cl3RuC-CHCPh2 carbyne complex (7), an HCl adduct of previously elusive (PPh3)2Cl2RuCCCPh2 complex 6 in high yields. In contrast to the formation of complex 3, the reaction in a non-coordinating solvent did not afford the rearrangement of the allenylidene C3-spine. Complex 7 was converted into complex 3 in thf under reflux under loss of a molecule HCl. Complex 7 was converted with triethylamine under loss of HCl to complex 6. Pentacoordinate complex 6 was crystallized in the presence of O-donor ligands (EtOH, MeOH and H2O) to give hexacoordinate (PPh3)2Cl2(ROH)RuCCCPh2 (R = H, CH3, C2H5) complexes (9)-(11) with the O-donor coordinating in trans-position to the allenylidene moiety. The reaction of complex 7 with 2 equiv. of 4-(N,N-dimethylamino)pyridine (DMAP) gave hexacoordinate (PPh3)2Cl2(DMAP)RuCCCPh2complex (12) with one molecule DMAP also coordinating in trans-position to the allenylidene group. Methanol and acetic acid in the absence of strong bases afforded the Fischer-carbene complexes (PPh3)2Cl2RuC(OCH3)-CHCPh2 (14) and (PPh3)2Cl2RuC(OAc)-CHCPh2 (15) where the nucleophile added to the α-carbon atom. The structures of complexes 5, 7, 9-11, 14, and 15 were solved via X-ray crystallography.  相似文献   

7.
The multifunctional ligands [(Z)-FcCCSC(H)C(H)XR] [X = O, R = Me (2a); X = O, R = Et (2b); X = S, R = Ph (3); X = S, R = C6F5 (5)] and [(Z,Z)-Fc(SR)CC(H)SC(H)C(H)SR] [R = Ph (4), C6F5 (6)] have been prepared through hydroalkoxylation and hydrothiolation processes of the alkyne groups in the compound FcCCSCCH 1. Reactions between compound 3 and the carbonyl metals Co2(CO)8, Os3(CO)10(NCMe)2 and Fe2(CO)9 have allowed the synthesis of the polynuclear compounds [(Z)-{Co2(CO)6}(μ-η2-FcCCSC(H)C(H)SPh)] 9, [(Z)-Os3(CO)9(μ-CO){μ32-FcCCSC(H)C(H)(SPh)}] 10 and [(Z)-{Fe3(CO)9}[μ33-(CCS)-FcCCSC(H)C(H)(SPh)] 11. All the compounds have been characterized by elemental analysis, 1H and 13C{1H} NMR spectroscopy, mass spectrometry and the crystal structure of compounds [(Z)-FcCCSC(H)C(H)OMe] 2a and [{Co2(CO)6}2(μ-η22-FcCCSCCSiMe3)] 7 have been solved by X ray diffraction analysis.  相似文献   

8.
The coordination chemistry of the fluorovinyl substituted phosphines PPh2(Z-CFCFH) and PPh2(E-CClCFH) with K2MX4 (M = Pd, Pt; X = Cl, Br, and I) salts has been investigated resulting in the first reported palladium(II) and platinum(II) complexes of phosphines containing partially fluorinated vinyl groups. The complexes have been characterised by a combination of multinuclear [1H, 13C{1H}, 19F, 31P{1H}] NMR spectroscopy, and IR/Raman spectroscopy. The single-crystal X-ray structures of trans-[PdX2{PPh2(CFCFH)}2], X = Cl (1), Br (2), I (3), trans-[PdCl2{PPh2(CClCFH)}2] (4), cis-[PtX2{PPh2(CFCFH)}2], X = Cl (5), Br (6), trans-[PtI2{PPh2(CFCFH)}2] (7), and both cis- and trans-[PtCl2{PPh2(CClCFH)}2] (8), have been determined. Results obtained from spectroscopic and crystallographic data suggest that replacement of a β-fluorine by hydrogen, whilst reducing the steric demand of the ligand, has little effect on the electronic character of the ligand. The presence of a proton in the vinyl group results in short proton-halide secondary interactions in the solid state (d(H?X) = 2.72(3) for 1, and 2.92(5) Å for 2) forming an infinite chain ribbon motif.  相似文献   

9.
The thiocarbonyl analogue of Vaska’s compound is produced in high yield by first treating IrCl(CO)(PPh3)2 with CS2 and methyl triflate to give [Ir(κ2-C[S]SMe)Cl(CO)(PPh3)2]CF3SO3 (1), secondly, reacting 1 with NaBH4 to give IrHCl(C[S]SMe)(CO)(PPh3)2 (2), and finally heating 2 to induce elimination of both MeSH and CO to produce IrCl(CS)(PPh3)2 (3). When IrCl(CS)(PPh3)2 is treated with Hg(CHCHPh)2 the novel 2-iridathiophene, Ir[SC3H(Ph-3)(CHCHPh-5)]HCl(PPh3)2 (4) is produced. The X-ray crystal structure of the iodo-derivative of 4, Ir[SC3H(Ph-3)(CHCHPh-5)]HI(PPh3)2 (5) confirms the unusual 2-metallathiophene structure. Treatment of IrCl(CS)(PPh3)2 with Hg(CHCPh2)2 produces both a coordinatively unsaturated 1-iridaindene, Ir[C8H5(Ph-3)]Cl(PPh3)2 (6) and a chelated dithiocarboxylate complex, Ir(κ2-S2CCHCPh2)Cl(CHCPh2)(PPh3)2 (7). X-ray crystal structure determinations for 6 and 7 are reported.  相似文献   

10.
A series of chiral ansa-zirconocene ester enolate complexes incorporating C2- or Cs-symmetric ligands, including neutral rac-(EBI)ZrCl[OC(OiPr)CMe2] (1), rac-(EBI)Zr(OTf)[OC(OiPr)CMe2] (2), rac-(EBI)Zr(OTf)[OC(OMe)C(Me)CH2C(Me2)C(OiPr)O] (3), [Me2C(Cp)(Flu)]ZrMe[OC(OiPr)CMe2] (4), and cationic [Me2C(Cp)(Flu)]Zr+(THF)[OC(OiPr)CMe2][MeB(C6F5)3] (5), have been synthesized. Within the neutral C2-ligated zirconocene ester enolate series, the chloride derivative 1 is inactive toward any methyl methacrylate (MMA) additions, the methyl derivative rac-(EBI)ZrMe[OC(OiPr)CMe2] adds cleanly only 1 equiv. of MMA, and the triflate derivative 2 can add either 1 equiv. of MMA to form the single-MMA-addition product 3 or multiple equivalents of MMA to form P(MMA). Unlike the Cs-ligated methyl cation [Me2C(Cp)(Flu)ZrMe]+, which is inactive for MMA polymerization under various conditions, the Cs-ligated ester enolate cation 5 is moderately active for polymerization of MMA and N,N-dimethylacrylamide at ambient temperature; the resulting P(MMA) has a high molecular weight of Mn = 388 000 Da but a low syndiotacticity of [rr] = 64%, and the polymerization conforms to a chain-end control mechanism.  相似文献   

11.
12.
13.
The dimetallacyclopentenone complexes [Fe2Cp2(CO)(μ−CO){μ−η13−CαHCβ(R)C(O)}] (R = CH2OH, 1a; R = CMe2OH, 1b; R = Ph, 1c) were prepared by photolytic reaction of [Fe2Cp2(CO)4] with alkyne according to the literature procedure. The X-ray and the electrochemical characterization of 1c are presented. The μ-allenyl compound [Fe2Cp2(CO)2(μ−CO){μ−η12α,β−CαHCβCMe2][BF4] ([2][BF4]), obtained by reaction of 1b with HBF4, underwent monoelectron reduction to give a radical species which was detected by EPR at room temperature. The EPR signal has been assigned to [Fe2Cp2(CO)2(μ−CO){μ−η12α,β-CαHCβCMe2}], [2]. The molecular structures of [2]+ and [2] were optimized by DFT calculations. The unpaired electron in [2] is localized mainly at the metal centers and, coherently, [2] does not undergo carbon-carbon dimerization, by contrast with what previously observed for the μ-vinyl radical complex [Fe2Cp2(CO)2(μ−CO){μ−η12-CHCH(Ph)}], [3]. Electron spin density distributions similar to the one of [2] were found for the μ-allenyl radical complexes [Fe2Cp2(CO)2(μ-CO){μ-η12α,β-CαHCβC(R1)(R2)}] (R1 = R2 = H, [4]; R1 = H, R2 = Ph, [5]; R1 = R2 = Ph, [6]).  相似文献   

14.
A comparative study of the electrochemical properties, 57Fe NMR and Mössbauer spectroscopic data of compounds [(η5-C5H5)Fe{(η5-C5H4)-C(R1)N-R2}] {R1 = H, R2 = CH2-CH2OH (1a), CH(Me)-CH2OH (1b), CH2C6H5 (1c), C6H4-2Me (1d), C6H4-2SMe (1e) or C6H4-2OH (1f) and R1 = C6H5, R2 = C6H4-2Me (2d)} is reported. The X-ray crystal structure of [(η5-C5H5)Fe{(η5-C5H4)-CHN-C6H4-2OH}] (1f) is also described. Density functional theoretical (DFT) studies of these systems have allowed us to examine the effects induced by the substituents of the “-C(R1)N-R2” moiety or the aryl rings (in 1d-1f) upon the electronic environment of the iron(II) centre.  相似文献   

15.
The reaction of diphosphinohydrazine PhNH-N(PPh2)2 (1) with cobalt(II) silylamide, Co[N(SiMe3)2]2, proceeds via formation of unstable phosphinohydrazide complex Co[NPh-N(PPh2)2]2 followed by rearrangement to a new chelating compound Co(NPh-PPh2N-PPh2)2 (2). Disproportionation of nickel(I) silylamide, (Ph3P)2Ni-N(SiMe3)2, in the presence of 1, yields Ni(0) and Ni(II) phosphinoamide complexes: Ni[(Ph2P)2N-NPhH]2 (3), Ni(NPh-PPh2N-PPh2)2 (4). X-ray analysis reveals tetrahedral environment of the cobalt atom in 2 and square-planar environment of the nickel atom in cis-4. In contrast to the crystalline patterns, the solutions of 2 in THF or toluene have EPR signal which is typical to square-planar low-spin d7 cobalt complex. The reactions of 2 with dioxygen, elemental sulfur and diphenyldiazomethane led to the spirocyclic insertion products Co(NPh-PPh2N-PPh2X)2 (X = O, S, NNCPh2) while the absorption of carbon monoxide is reversible.  相似文献   

16.
The metallacyclic complexes (OC)4MC(η2-NHCH2CHCHX)Fc (4; X = H) and (5; X = CH2OH) [M = Cr: a; Mo: b; W: c; Fc = ferrocenyl = CpFe(C5H4)] were obtained in good yields upon photo-decarbonylation of the bimetallic allylaminocarbene complexes (OC)5MC(NHCH2CHCHX)Fc (2; X = H)/(3; X = CH2OH). At room temperature complexes 2/3 exist as mixtures of E- and predominantly Z-isomers with regard to the C-N bond. The molecular structures of 4b and 4c were determined by X-ray diffraction analyses. The intermetallic communicative effects and the interplay of Fc and η2-alkene moieties of 4a and 4b were assessed by cyclovoltammetry. All complexes were also characterized in solution by one- and two-dimensional NMR spectroscopy (1H, 13C, 1H NOE, 1H/1H COSY, 13C/1H HETCOR).  相似文献   

17.
18.
The oxime-substituted NCN-pincer molecules HONCH-1-C6H3(CH2NMe2)2-3,5 (2a) and HONCH-4-C6H2(CH2NMe2)2-2,6-Br-1 (2b) were accessible by treatment of the benzaldehydes H(O)C-4-C6H3(CH2NMe2)2-3,5 (1a) and H(O)C-4-C6H2(CH2NMe2)2-2,6-Br-1 (1b) with an excess of hydroxylamine. In the solid state both compounds are forming polymers with intermolecular O-H?N connectivities between the Me2NCH2 substituents and the oxime entity of further molecules of 2a and 2b, respectively. Characteristic for 2a and 2b is a helically arrangement involving a crystallographic 21 screw axis of the HONCH-1-C6H3(CH2NMe2)2-3,5 and HONCH-4-C6H2(CH2NMe2)2-2,6-Br-1 building blocks.The reaction of 2b with equimolar amounts of [Pd2(dba)3 · CHCl3] (3) (dba = dibenzylidene acetone) or [Pt(tol)2(SEt2)]2 (4) (tol = 4-tolyl) gave by an oxidative addition of the C-Br unit to M coordination polymers with a [(HONCH-4-C6H2(CH2NMe2)2-2,6)MBr] repeating unit (5: M = Pd, 6: M = Pt). Complexes 5 and 6 are in the solid state linear hydrogen-bridged polymers with O-H?Br contacts between the oxime entities and the metal-bonded bromide.  相似文献   

19.
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