共查询到20条相似文献,搜索用时 15 毫秒
1.
Oxidation of Mixed Ligand Nickel(0) Complexes by Organic Halides The oxidation of (dipy)Ni(PPh3)2 by alkyl and aryl iodides or bromides affords the nickel(I) complexes (dipy)Ni(PPh3)X (X = Br, I). No normal products of oxidative addition are obtained. But in the case of methyl and ethyl halides complexes of the type (dipy)NiR2 are formed as intermediates. Basing on the identified final products and on the correalation between the reactivity of the organic halides and their polarographic half wave potentials a mechanism of the reaction is proposed. The first step is a charge transfer from nickel(0) to the organic halide. Further synthesis, reactions, and the ESR-spectra of the complexes (dipy)Ni(PPh3)X and a synthesis of (dipy)Ni(CH2Ph)2 are described. Experiments to prepare pure (dipy)Ni(PPh3)Cl had no success. 相似文献
2.
Oxidation of Nickel(0) Complexes by Cyclic Imides of Dicarbonic Acids Normally, phthalimide (PI? H) or succinimide (SI? H) react with nickel(0) complexes — (dipy)Ni(COD) or (Ph3P)2Ni(C2H4) — by oxidative addition. The reaction of PI? H and the strong reductant (dipy)Ni(COD) is initiated by a one-electron transfer. Depending on the solvent, the resulting ion pair affords (dipy)NiI(PI) by spontaneous fragmentation or (dipy)NiII(H)(PI) by cage collaps. No interaction is found between the weak reductant (Ph3P)Ni(C2H4) and PI? H. Phosphine-containing nickel(0) complexes are electrophilically attacked by the acid NH group of SI? H. Hydrido complexes of nickel(0), such as (Cy3P)2Ni(H)(SI), or secondary products of them, such as [(SI)Ni(THF)]2NH, are formed. On the other hand, the reaction with (dipy)Ni(COD) affords only the binuclear substitution product [(dipy)Ni]2(SI? H)(THF). In solution prolongated heating of (dipy)Ni(PI)(THF)0,5 results in a partial decarbonylation. In contrast to the reaction of (dipy)Ni(COD) and cyclic carbonic acid anhydrides, no definite metalla rings but by an interaction with the solvent, benzamide is formed. With (dipy)Ni(COD) maleinimide does not react like on NH-acidic compound but like a polar olefine by substitution. 相似文献
3.
The neutral complexes (η5-C5H5NiXL (X = Cl, L = PPh3 (I); L = PCy3 (II); X = Br, L = PPh3 (III); L = PCy3 (IV); X = I, L = PPh3 (V); L = PCy3 (VI)) have been obtained by treating NiX2L2 with thallium cyclopentadienide. The same reaction in the presence of TlBF4 gives cationic derivatives [(η5-C5H5)NiL2]BF4 (L = 2PPh2Me (VII); L = dppe (VIII)), whereas mononuclear complexes containing two different ligands (L2 = PPh3 + PCy3 (IX)) or dinuclear [(η5-C5H5)Ni(PPh3)]2dppe(BF4)2 (X) are obtained from the reaction of III with TlBF4 in the presence of a different ligand. Reduction of cationic complexes with Na/Hg gives very unstable nickel(I) derivatives (η5-C5H5)NiL2, which could not be isolated purely. Similar reduction of neutral complexes under CO gives a mixture of decomposition products containing [(η5-C5H5)Ni(CO)]2 and nickel(o) carbonyls, whereas in the presence of acetylenes, dinuclear [(η5-C5H5)Ni]2(RCCR′) (R = R′ = Ph; R = Ph, R′ = H) are obtained. 相似文献
4.
(dipy)Ni(COD) react with duroquinone (Dch) or anthraquinone (Ach) to yield the complexes (dipy)Ni(η4 -Dch) or (dipy)Ni(η4 -Ach). Chloranil (CA), however, reacts as an oxidant and depending on the temperature (dipy)NiII(CA2-) or following an oxidative addition (dipy)NiII(Cl)(CAH-)(THF) are formed.By substitution of (Cy3P)2Ni(C2H4) the complexes (Cy3P)Ni(η4-Dch) or (Cy3P)2Ni(η4 -Ach) are obtained, whereas a 1,1-coupling of quinone and the coordinated phosphine proceeds during the reaction between p-benzoquinone of chloranil and (Cy3P)2Ni(C2H4). By ESR studies it was demonstrated that with Ni(Cy3P?Ch)2 or Ni(Cy3P?CA)2, resp., complexes are obtained, in which radical anions, which are derived from the product of this 1,1-coupling, are coordinated to low-spin nickel (II). There is a significant difference between (Cy3P)2Ni(C2H4) and the analogous platinum or palladium complexes, which are substituted by p-benzoquinone while an oxidative addition proceeds with chloranil. 相似文献
5.
D. B. Furman N. V. Volchkov L. S. Isaeva L. N. Morozova D. N. Kravtsov O. V. Bragin 《Russian Chemical Bulletin》1988,37(11):2220-2222
Conclusions By studying the liquid-phase dimerization of ethylene in the presence of Cat-Et3Al2-Cl3 catalytic systems based on a nickel complex heterogenized on Al2O3 and a number of model nickel complexes, a similar activity and selectivity of the process has been established (Cat=NiPPh3(CO)2L, where L=PPh3, CO, Al2O3; Ni(PPh3)2(CO)2; Ni(PPh3)2(2-C2H4); Ni[P(C6H11)3]2(H)Cl and Ni(PPh3)(Et)Cl).The results of the investigation agree with the hypothesis that mono- and diolefinic nickel complexes are formed as the active intermediates in the reaction.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2466–2469, November, 1988. 相似文献
6.
Reactions of π-Organonickel Complexes with Tertiary Phosphanes In a hexane solution Ni(C5H5)2 reacts with PBu3 or Ph2PBu forming the nickel(O) complexes Ni(PBu3)4 or Ni(Ph2PBu)4 (A). Under the same conditions only one cyclopentadienyl ligand is substituted by PhPBu2 and the nickel(I) compound (C5H5)Ni (PhPBu2)2 (B) is obtained. Products of the reactions between B and α,α′-dipyridyl, hydrogen chlorid in ether, or Ni(PhPBu2),Cl2 are Ni(dipy)2, [PhPHBu2]2[NiCl4], or (C5H5) Ni(PhPBu2)2Cl. By the reaction with HgCl2 a cyclopentadienyl compound of an unknown structur is formed. The compound Ni(PhPBu2)4 which is analogous to A is synthesized by the reduction of bis(acety1acetonato)-nickel with Et2AlOEt in the presence of PhPBu2 or by the reaction of bis (cyclooctadiene-1,5)-nickel with PhPBu2. 相似文献
7.
Cyclic α, β-Unsaturated Carbonyl Compounds as Ligands in Nickel (0) Complexes . As a result of the reaction of (Cy3P)2Ni(C2H4) with p-benzoquinone (p-CH) or maleic anhydride (MSA), nickel(II)-complexes of radical anions are formed which are derived from PCy3 and p-CH or MSA by an equimolecular coupling. With other cyclic α, β-unsaturated carbonyl compounds (L = 1,4-naphthoquinone, substituted α- and γ-pyrones, substituted coumarins) no comparable reactions proceed in the coordination sphere of nickel(0) phosphine complexes. But depending on the phosphine and on the substrate compounds of the types (R3P)2NiL or (R3P)NiL are obtained. Taking the substituted coumarins for an example, it was demonstrated that the latter type is favoured by bulky phosphines (PCy3) and by coumarins with a high π-acceptor strength. The i.r. spectra of the complexes (R3P)NiL are in accordance with an η3(C?C,O)-bridging function of α, β-unsaturated carbonyl ligands and therefore with an oligomeric structure. For the complexes (R3P)2NiL and (dipy)NiL an η2(C?C) or a pseudo-η3 (C?C,C) coordination of the ligands is discussed. Of special interest are the compounds (Cy3P)Ni(DMP) and (Cy3P)Ni(BDH) (DMP = 2, 6-dimethyl-γ-pyrone, BDH = 2-benzylidene-1, 3-dioxo-hydrindene). Possibly the substituted γ-pyrone is an η6-ligand in (Cy3,P)Ni(DMP). (Cy3,P)Ni(BDH) is considered to be a nickel(II) chelate of a diva-lent anion which is derived from BDH by the uptake of two electrons. In this connection the limits for a classification of the new complexes as nickel(0) or nickel(II) compounds are mentioned. The polarographic half-wave potentials are applied to an estimation of the reactivity of the α, β-unsaturated carbonyl compounds related to nickel(0) complexes. 相似文献
8.
Mujie Yang Lingjun Zhang Zhigang Cai Peiqing Yang Zhiling Xu 《Journal of polymer science. Part A, Polymer chemistry》1995,33(13):2203-2208
The synthesis of the nickel dialkynyl complex Ni(C?C? C6H4? C?CH)2(PPh3)2 and of the corresponding polyyne polymer containing nickel in the main chain ? [Ni(PPh3)2? C?C? C6H4? C?C? ]n are described and discussed. A new mixed solvent system DMSO/HNEt2 and homogeneous step-wise condensation method used for their synthesis are presented for the first time. The Ni-polyyne polymer obtained is dark yellow powder and soluble in THF or CH2Cl2. Its M?w is about 104, and the MWD is less than 2. Both the prepared complex and polymer have been characterized by IR, UV, 1H-NMR, and DTA. Preliminary results on photoluminesence of nickel polyyne polymers are present. © 1995 John Wiley & Sons, Inc. 相似文献
9.
Yu. Yu. Titova L. B. Belykh A. V. Rokhin O. G. Soroka F. K. Schmidt 《Kinetics and Catalysis》2014,55(1):35-46
The catalytic characteristics of the individual complex Ni(PPh3)2(C2H4) and Ni(PPh3) n Cl (n = 2 or 3) and those of systems based on these complexes in combination with Brönsted and Lewis acids in ethylene and propylene oligomerization have been determined. A correlation between the BF3 · OEt2 solution storage time and the catalytic properties of the nickel systems has been established for the reactions of the lower alkenes. The observed increase in the turnover frequency and turnover number of the catalyst is due to the increase in the Brörsted acid concentration as a result of irreversible conversions of BF3 · OEt2 caused by its interaction with impurity water in the solvent. The formation of the Ni(PPh3)2(C2H4)-BF3 · OEt2 catalytic system in the presence of a substrate dramatically extends the system’s service life. The interaction of the nickel precursors with boron trifluoride etherate has been investigated using a complex of physical methods, and the main reactions yielding catalytically active species have been revealed. 相似文献
10.
Eiji Ihara Takenori Fujimura Hajime Yasuda Tatsuya Maruo Nobuko Kanehisa Yasushi Kai 《Journal of polymer science. Part A, Polymer chemistry》2000,38(Z1):4764-4775
A series of nickel complexes, including Ni(acac)2, (C5H5)Ni(η3‐allyl), and [NiMe4Li2(THF)2]2, that were activated with modified methylaluminoxane (MMAO) exhibited high catalytic activity for the polymerization of methyl methacrylate (MMA) but showed no catalytic activity for the polymerization of ethylene and 1‐olefins. The resulting polymers exhibited rather broad molecular weight distributions and low syndiotacticities. In contrast to these initiators, the metallocene complexes (C5H5)2Ni, (C5Me5)2Ni, (Ind)2Ni, and (Me3SiC5H4)2Ni provided narrower molecular weight distributions at 60 °C when these initiator were activated with MMAO. Half‐metallocene complexes such as (C5H5)NiCl(PPh3), (C5Me5)NiCl(PPh3), and (Ind)NiCl(PPh3) produced poly(methyl methacrylate) (PMMA) with much narrower molecular weight distributions when the polymerization was carried out at 0 °C. Ni[1,3‐(CF3)2‐acac]2 generated PMMA with high syndiotacticity. The NiR(acac)(PPh3) complexes (R = Me or Et) revealed high selectivity in the polymerization of isoprene that produced 1,2‐/3,4‐polymer at 0 °C exclusively, whereas the polymerization at 60 °C resulted in the formation of cis‐1,4‐rich polymers. The polymerization of ethylene with Ni(1,3‐tBu2‐acac)2 and Ni[1,3‐(CF3)2‐acac]2 generated oligo‐ethylene with moderate catalytic activity, whereas the reaction of ethylene with Ni(acac)2/MMAO produced high molecular weight polyethylene. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 4764–4775, 2000 相似文献
11.
J.F. van Baar J.M. Klerks P. Overbosch D.J. Stufkens K. Vrieze 《Journal of organometallic chemistry》1976,112(1):95-103
The reactions of some cyclometallated azo and imino compounds have been studied. Treatment of [IrHX(PhCCHCHNC3H7)(PCy3)2] with X2 (X = Cl, Br) yields substitution products [IrHX(PhCCXCHNC3H7)(PCy3)2] without rupture of the IrC bond. Treatment of [IrHCl(5-CH3 · C6H3CHNCH3) (PPh3)2] with AgClO4 and then with CNC6H11 or CO (= L) leads to the formation of the complexes [IrHL(5-CH3 · C6H3CHNCH3)(PPh3)2]ClO4, the metallocyclic ring remaining intact. Rupture of the metallocyclic ring is observed when [PdCl(C6H4NNPh)]2 is treated under mild conditions with CNC6H11, and the insertion product [PdCl(CNC6H11)2 {(CNC6H11)2C6H4NNPh} ] is obtained.Possible mechanisms for the reactions are discussed. 相似文献
12.
The reactions of EtNi(PPh3)(acac) with various reagents have been discussed; the reaction with NaFe(CO)2Cp or Fe(CO)5 occurs via nickel(II) reductive carbonylation while EtNi(PPh3)(acac) and Et2AlCl afford the unstable EtNi(PPh3)2-Cl. The cleavage of the NiC bond with evolution of ethylene and ethane is observed when EtNi(PPh3)(acac) reacts with CS2, HgCl2 and Et2AlBr. A new nickel hydride complex, (Ph3P)3Ni(H)Br, has been obtained from EtNi(PPh3)-(acac) and Et2AlBr and its properties have been studied. Another method of synthesis of this hydride complex directly from Ni(acac)2 and Et2AlBr has been proposed. 相似文献
13.
C.T. Mortimer M.P. Wilkinson R.J. Puddephatt 《Journal of organometallic chemistry》1975,102(4):C43-C45
The enthalpy of the reaction: Pt(PPh3)2(CH2CH2)(cryst.) + CS2(g) → Pt(PPh3)2(CS2)(cryst.) + CH2CH2(g) has been determined as ΔH = ? 4.40 ± 2.2 kJ mol?1 from solution calorimetry, and the bond dissociation energy D(PtCS2) shown to be slightly greater than D(PtC2H4). 相似文献
14.
Prof. Dr. Tarlok S. Lobana Poonam Kumari Gagandeep Bawa Geeta Hundal Ray J. Butcher Francisco J. Fernandez Jerry P. Jasinski James A. Golen 《无机化学与普通化学杂志》2012,638(5):804-810
Complexes of pyrrole‐2‐carbaldehyde thiosemicarbazones, [(C4H4N4)(H)C2=N3–N2(H)–C1(=S)–N1HR; R = Ph, H2L1; Me, H2L2; H, H2L3] with nickel(II) and palladium(II) are described. The reaction of nickel(II) acetate with H2L1 in methanol in 1:1 molar ratio yielded a complex of composition, [Ni(κ2‐N3,S‐HL1)2] ( 1 ). Likewise reaction of NiCl2 with H2L2 in 1:1 molar ratio in acetonitrile in the presence of triethylamine base followed by the addition of pyridine did not yield the anticipated [Ni(κ3‐N4,N3,S‐L2)(py)] complex, moreover a bis‐square‐planar complex, [Ni(κ2‐N3,S‐HL2)2] ( 2 ) was formed. However, in the presence of bipyridine (bipy), it yielded the addition product, [Ni(κ2‐N3,S‐HL2)2(κ2‐N, N‐bipy)] ( 3 ). Reaction of PdCl2(κ2‐P, P–PPh2–CH2–PPh2) with H2L3 in toluene in the presence of triethylamine has yielded a complex of stoichiometry, [Pd(κ3‐N4,N3,S–L3)(κ1‐P–PPh2–CH2–P(O)Ph2] ( 4 ). The ligands (HL1)– and (HL2)– are chelating to NiII metal atom as anions binding through N3,S‐donor atoms with pendant pyrrole groups, and (L3)2– is chelating to the PdII metal atom as dianion through N4,N3,S‐donor atoms (pyrrole is N4‐bonded). Fourth site in 4 is bonded to one P‐donor atom of PPh2–CH2–P(O)Ph2, whose pendant –PPh2 group involves auto oxidation to –P(O)PPh2 during reaction. These complexes were characterized using analytical data, IR, NMR (1H, 31P) spectroscopy and X‐ray crystallography. Complexes 1 , 2 , and 4 have square‐planar arrangement, whereas complex 3 is octahedral. 相似文献
15.
Reactions of π-cyclopentadienylbis(triphenylphosphine)rhodium(I) (I) with alkyl halides, olefins, acetylenes, carbon disulfide and elementary sulfur have been investigated. Methyl iodide gives the oxidative-addition product [πC5H5 Rh(PPh3)2CH3]I but isopropyl iodide produces the alkyl substituted-cyclopentadienyl complex (π-i-C3H7C5H4)Rh(PPh3)I2. Under a nitrogen atmosphere, olefins and acetylenes give compounds of the composition π-C5H5 Rh(PPh3)(L) (L = CH2—CHCN, CH2—CHCO2CH3, CH3O2—CCOO2CH3).In the presence of air, however, complexes of the composition π-C5H5Rh(L)2 (L = CH2—CHCN, CH2—CHCO2CH3, CH2—C(CH3)CN) and π-C5H5Rh(L)3 (L = CH3O2 CC—CCO2 CH3, PhC—CCO2 CH3) are formed. The reaction of carbon disulfide or sulfur with (I) also gives the compounds π-C5H5Rh(PPh3)(L) (L = CS2, CS3, S5). 相似文献
16.
《Journal of Coordination Chemistry》2012,65(3):482-494
Mononuclear palladium(II) complexes 1–12, (C6H4X-4)PdX?(PR3)2 (X?=?I, Br, or Cl; X??=?I or Br; R?=?Ph, Cy, Et, or Me), were synthesized by oxidative addition of 1,4-dihalogenated benzene to Pd(PR3)4; dinuclear palladium(II) complexes 13–15, (Me3P)2XPd(C6H4-1,4)PdX?(PMe3)2 (X, X??=?I or Br), could be obtained only using trimethylphosphine. Another method to prepare 13–15 is via re-oxidative addition of the corresponding mononuclear palladium(II) complexes and Pd(PMe3)4. Using 4,4′-dibromobiphenyl as the starting material, the mononuclear palladium(II) complexes [C6H4(C6H4Br-4)-4]PdBr(PPh3)2 (16) and [C6H4(C6H4Br-4)-4]PdBr(PCy3)2 (17) with bulky phosphines could be synthesized at relative low temperature, while dinuclear 18, (Cy3P)2BrPd(C6H4C6H4-4,4?)PdBr(PCy3)2, was prepared by bis-oxidative addition at higher temperature. The re-oxidative addition of 16 and Pd(PMe3)4 gave dinuclear 19, (Me3P)2BrPd(C6H4C6H4-4,4?)PdBr(PMe3)2, accompanying phosphine exchange. X-ray diffraction analysis revealed that formation of dinuclear palladium(II) complexes depends on the reaction temperature, phosphine ligands, and bridging groups. 相似文献
17.
Detailed procedures for the syntheses of Os(CO)2(PPh3)3, Os(CO)(CNR)-(PPh3)3 (R = p-tolyl), Os(CO)(CS)(PPh3)3 and Os(CS)(CNR)(PPh3)3, together with the derived complexes Os(CO)2(CS)(PPh3)2, Os(CO)(CS)(CNR)(PPh3)2, Os(η2-C2H4)(CO)(CNR)(PPh3)2, Os(η2-C2H4)(CO)(CS)(PPh3)2, Os(η2CS2)(CO)2-(PPh3)2, Os(η2CS2)(CO)(CS)(PPh3)2, Os(η2-CS2)(CO)(CNR)(PPh3)2, Os(η2PhC2Ph)(CO)2(PPh3)2 and OsH(C2Ph)(CO)2(PPh3)2 are described. 相似文献
18.
A series of ferrocene-based organosilicon compounds have been prepared via hydrosilylation or double silylation of carbonyl compounds with 1,1′-bis(dimethylsilyl)ferrocene using (C2H4)Pt(PPh3)2 or Ni(PEt3)4 catalysts. In general, while the platinum catalyst (C2H4)Pt(PPh3)2 preferentially produced cyclic double-silylated products, the Ni(PEt3)4 catalyst led to the hydrosilylated ferrocene products from aldehydes or ketones. 相似文献
19.
The synthesis, characterization and methyl methacrylate polymerization behaviors of 2‐(N‐arylimino)pyrrolide nickel complexes are described. The nickel complex [NN]2Ni ( 1 , [NN] = [2‐C(H)NAr‐5‐tBu‐C4H2N]?, Ar = 2,6‐iPr2C6H3) was prepared in good yield by the reaction of [NN]Li with trans‐[Ni(Cl)(Ph)(PPh3)2] in THF. Reaction of [NN]Li with NiBr2(DME) yielded the nickel bromide [NN]Ni(Br)[NNH] ( 2 ). Complexes 1 and 2 were characterized by 1H NMR and IR spectroscopy and elemental analysis, and by X‐ray single crystal analysis. Both complexes, upon activation with methylaluminoxane, are highly active for the polymerization of methyl methacrylate to give high molecular weight polymethylmethacrylate with narrow molecular distributions. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
20.
The reactions of Pd(2-MeC3H4)2 with PdL2(L = P(i-Pr)3, PCy3) in the molar ratio of produce the binuclear complexes (2-MeC3H4)2Pd2L2 in which the bridging 2-methylallyl ligands are symmetrically linked to both metal atoms. The methods of “1 + 1” addition has also been applied to prepare (2-MeC3H4(X)Pd2L2 (X = Cl, L = P(i-Pr)3, P(t-Bu)3, PCy3; X = I, L = P(i-Pr)3) which contain one 2-methylallyl and one halogen ligand in a bridging position. Attemps to synthesize similar binuclear complexes with NiNi, PtPt and NiPd bonds failed. The reaction of [C8H12RhCl]2 and Pd[P(i-Pr)3]2 gives C8H12Rh[P(i-Pr)3]Cl. 相似文献