共查询到20条相似文献,搜索用时 15 毫秒
1.
Zhu Yinghuai Shirley Lo Pei Sia Fethi Kooli Keith Carpenter Richard A. Kemp 《Journal of organometallic chemistry》2005,690(26):6284-6291
In situ reaction of Li[closo-1-Ph-1,2-C2B10H10] with 7-azabicyclo [4.1.0] heptane results in the formation of the disubstituted carborane, closo-1-Ph-2-(2′-aminocyclohexyl)-1,2-C2B10H10 (1), in 63% yield. Decapitation of (1) with potassium hydroxide in refluxing ethanol produces the cage-opened nido-carborane, K[nido-7-Ph-8-(2′-aminocyclohexyl)-7,8-C2B9H10]− (2), in 80% yield. Deprotonation of the above monoanion with two equivalents of n-butyllithium followed by reaction with anhydrous MCl4 · 2THF (M = Zr, Ti) provides d0-half-sandwich metallocarboranes, closo-1-M(Cl)-2-Ph-3-(2′-σ-(H)N-cyclohexyl)-2,3-η5-C2B9H9 (3 M = Zr; 4 M = Ti) in 53% and 42% yields, respectively. The reaction of Li[closo-1,2-C2B10H11] with 7-azabicyclo [4.1.0] heptane in THF affords closo-1-(2′-aminocyclohexyl)-1,2-C2B10H10 (5) in 59% yield. Immobilization of the carboranyl amino ligand (1) to an organic support, Merrifield’s peptide resin (1%), has been achieved by the reaction of the sodium salt of (5) with polystyryl chloride in THF to produce closo-1-(2′-aminocyclohexyl)-2-polystyryl-1,2-C2B10H10 (6) in 87% yield. Further reaction of the dianion derived from (6) with anhydrous ZrCl4 · 2THF led to the formation of the organic polystyryl supported d0-half-sandwich metallocarborane, closo-1-Zr(Cl)-2-(2′-σ-(H)N-cyclohexyl)-3-polystyryl-2,3-η5-C2B9H9 (7), in 38% yield. These new compounds have been characterized by elemental analyses, NMR, and IR spectra. Polymerizations of both ethylene and vinyl chloride with (3) and (7) have been performed in toluene using MMAO-7 (13% ISOPAR-E) as the co-catalyst. Molecular weights up to 32.8 × 103 (Mw/Mn = 1.8) and 9.5 × 103 (Mw/Mn = 2.1) were obtained for PE and PVC, respectively. 相似文献
2.
Jianhui Wang Yinghuai Zhu Shoujian Li Chong Zheng John A. Maguire Narayan S. Hosmane 《Journal of organometallic chemistry》2003,680(1-2):173-181
The reactions of RNHSi(Me)2Cl (1, R=t-Bu; 2, R=2,6-(Me2CH)2C6H3) with the carborane ligands, nido-1-Na(C4H8O)-2,3-(SiMe3)2-2,3-C2B4H5 (3) and Li[closo-1-R′-1,2-C2B10H10] (4), produced two kinds of neutral ligand precursors, nido-5-[Si(Me)2N(H)R]-2,3-(SiMe3)2-2,3-C2B4H5, (5, R=t-Bu) and closo-1-R′-2-[Si(Me)2N(H)R]-1,2-C2B10H10 (6, R=t-Bu, R′=Ph; 7, R=2,6-(Me2CH)2C6H3, R′=H), in 85, 92, and 95% yields, respectively. Treatment of closo-2-[Si(Me)2NH(2,6-(Me2CH)2C6H3)]-1,2-C2B10H11 (7) with three equivalents of freshly cut sodium metal in the presence of naphthalene produced the corresponding cage-opened sodium salt of the “carbons apart” carborane trianion, [nido-3-{Si(Me)2N(2,6-(Me2CH)2C6H3)}-1,3-C2B10H11]3− (8) in almost quantitative yield. The reaction of the trianion, 8, with anhydrous MCl4 (M=Ti and Zr) in 1:1 molar ratio in dry tetrahydrofuran (THF) at −78 °C, resulted in the formation of the corresponding half-sandwich neutral d0-metallacarborane, closo-1-M[(Cl)(THF)n]-2-[1′-η1σ-N(2,6-(Me2CH)2C6H3)(Me)2Si]-2,4-η6-C2B10H11 (M=Ti (9), n=0; M=Zr (10), n=1) in 47 and 36% yields, respectively. All compounds were characterized by elemental analysis, 1H-, 11B-, and 13C-NMR spectra and IR spectra. The carborane ligand, 7, was also characterized by single crystal X-ray diffraction. Compound 7 crystallizes in the monoclinic space group P21/c with a=8.2357(19) Å, b=28.686(7) Å, c=9.921(2) Å; β=93.482(4)°; V=2339.5(9) Å3, and Z=4. The final refinements of 7 converged at R=0.0736; wR=0.1494; GOF=1.372 for observed reflections. 相似文献
3.
Jong-Dae Lee Ki-Chul Son Minserk Cheong Sang Ook Kang 《Journal of organometallic chemistry》2007,692(24):5403-5413
The syntheses of group 4 metal complexes containing the picolyldicarbollyl ligand DcabPyH [nido-7-HNC5H4(CH2)-8-R-7,8-C2B9H10] (2) are reported. New types of constrained geometry group 4 metal complexes (DcabPy)MCl2, [{(η5-RC2B9H9)(CH2)(η1-NC5H4)}MCl2] (M = Ti, 3; Zr, 4; R = H, a; Me, b), were prepared by the reaction of 2 with M(NMe2)2Cl2 (M = Ti, Zr). The reaction of 2 with M(NMe2)4 in toluene afforded (DcabPy)M(NMe2)2, [{(η5-RC2B9H9)(CH2)(η1-NC5H4)}M(NMe2)2] (M = Ti, 5; Zr, 6; R = H, a; Me, b), which readily reacted with Me3SiCl to yield the corresponding chloride complexes (DcabPy)MCl2 (M = Ti, 3; Zr, 4; R = H, a; Me, b). The structures of the diamido complexes (DcabPy)M(NMe2)2 (M = Ti, 5; Zr, 6) were established by X-ray diffraction studies of 5a, 5b, and 6a, which verified an η5:η1-bonding mode derived from the dicarbollylamino ligand. Related constrained geometry catalyst CGC-type alkoxy titanium complexes, (DcabPy)Ti(OiPr)2 (7), were synthesized by the reaction of 2 with Ti(OiPr)4. Sterically less demanding phenols such as 2-Me-C6H4OH replaced the coordinated amido ligands on (DcabPy)Ti(NMe2)2 (5a) to yield aryloxy stabilized CGC complexes (DcabPy)Ti(OPhMe)2(PhMe = 2- Me-C6H4, 8). NMR spectral data suggested that an intramolecular Ti-N coordination was intact in solution, resulting in a stable piano-stool structure with two aryloxy ligands residing in two of the leg positions. The aryloxy coordinations were further confirmed by single crystal X-ray diffraction studies on complexes (DcabPy)Ti(OPhMe)2 (8). 相似文献
4.
Erwan Le Grognec Rinaldo Poli Philippe Richard Rosa Llusar Santiago Uriel 《Journal of organometallic chemistry》2001,640(1-2):113-120
The reactions of the half-sandwich molybdenum(III) complexes CpMo(η4-C4H4R2)(CH3)2, where Cp=η5-C5H5 and R=H or CH3, with equimolar amounts of B(C6F5)3 have been investigated in toluene. EPR monitoring shows the formation of an addition product which does not readily react with Lewis bases such as ethylene, pyridine, or PMe3. The analysis of the EPR properties and the X-ray structure of a decomposition product obtained from dichloromethane, [CpMo(η4-C4H6)(μ-Cl)(μ-CH2)(O)MoCp][CH3B(C6F5)3], indicate that the borane attack has occurred at the methyl position. 相似文献
5.
G. G. Skvortsov M. V. Yakovenko G. K. Fukin E. V. Baranov Yu. A. Kurskii A. A. Trifonov 《Russian Chemical Bulletin》2007,56(3):456-460
The reactions of lanthanide tris(borohydrides) Ln(BH4)3(thf)3 (Ln = Sm or Nd) with 2 equiv. of lithium N,N′-diisopropyl-N′-bis(trimethylsilyl)guanidinate in toluene produced the [(Me3Si)2NC(NPri)2]Ln(BH4)2Li(thf)2 complexes (Ln = Sm or Nd), which were isolated in 57 and 42% yields, respectively, by recrystallization from hexane. X-ray
diffraction experiments and NMR and IR spectroscopic studies demonstrated that the reactions afford monomeric ate complexes, in which the lanthanide and lithium atoms are linked to each other by two bridging borohydride groups. The complexes
exhibit catalytic activity in polymerization of methyl methacrylate.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 441–445, March, 2007. 相似文献
6.
Alejandro Capap Ming-Dong Zhou Shu-Liang Zang Fritz E. Kühn 《Journal of organometallic chemistry》2008,693(20):3240-3244
Equimolar reactions of the derivatives of ((2-hydroxynapthalen-1-yl)methylene)aniline with methyltrioxorhenium (MTO) lead to complexes 1–4, where MTO is coordinated via the oxygen of the former hydroxyl-group to MTO. The resulting complexes are very stable but not particularly catalytically active if no electron acceptor resides on the Schiff base. The electron withdrawing groups placed on the Schiff base ligand have the effect of increasing the catalytic activity but somewhat decrease the complex stability. 相似文献
7.
Renan Cariou Atanas K. Tomov Andrew J.P. White 《Journal of organometallic chemistry》2009,694(5):703-265
Group 4 metal complexes bearing new phenoxy(benzimidazolyl)-imine, -amine and -amide ligands have been synthesized. A series of metal chloride derivatives has been prepared via treatment of MCl4(THF)2 (M = Ti, Zr, Hf) with the in situ generated sodium salt of the (benzimidazolyl)imine phenol 1. Reaction of the pro-ligand 2 with TiCl4(THF)2 afforded the corresponding complex 8 in which the amine proton remains bound to the nitrogen donor. Benzyl complexes of zirconium and hafnium were synthesized via treatment of pro-ligands 1 and 2 with M(CH2Ph)4 precursors. The complexes [NNO]M(CH2Ph)3 (6 M = Zr, 7 M = Hf) were found to undergo benzyl migration from the metal centre to the imine carbon of the ligand backbone giving complexes 11 and 12; the migration follows first order kinetics. The reaction of 1 with Ti(NMe2)4 led to the formation of an unusual C-C coupled product in which a new piperazine ring has formed. Complexes 11 and 12 undergo related transformations, leading to analogous C-C coupled products which were characterized by X-ray crystallography. Deuterium labelling experiments were carried out to determine the mechanistic pathway of the reactions. Chloride and benzyl complexes 3-12 were screened as pre-catalysts for olefin polymerization. 相似文献
8.
Leonard Joachim Pereira 《Journal of organometallic chemistry》2006,691(9):1941-1944
The monosubstituted clusters RuOs3(μ-H)2(CO)12(EPh3) (where E = P, As, Sb) exhibit isomers in which the group 15 ligand is on an Os or an Ru vertex. Evidence is presented for hydride fluxionality and EPh3 ligand migration. These processes have been examined by variable temperature NMR studies, and the kinetic parameters estimated. 相似文献
9.
Daniela Belli Dell’Amico Luca Labella Fabio Marchetti Simona Samaritani 《Journal of organometallic chemistry》2011,696(7):1349-1354
Convenient one-pot reduction-complexation reactions of hexachloroplatinato(IV) anions to (η4-alkadiene)dichloroplatinum(II) complexes (η4-alkadiene = COD, DAE, DCPD, NBD) under suitable phase-transfer catalysis conditions are reported. Reduction to zerovalent platinum alkene complexes has been obtained in the presence of an excess of alkene, potassium formate and 18-crown-6 as phase-transfer catalyst (alkene = COD, NB, dba). The crystal and molecular structure of [Pt1.03(dba)3]·CH2Cl2 has been studied by X-ray diffraction methods: it can be described as a solid solution of Pt(dba)3 and Pt2(dba)3, the mononuclear complex being largely prevailing. 相似文献
10.
Denis A Kissounko 《Journal of organometallic chemistry》2003,683(1):29-38
Protonation of the trimethylenemethane derivatives, Cp*Zr(σ2,π-C4H6)[N(R1)C(Me)N(R2)] (1a: R1=R2=i-Pr and 1b: R1=Et, R2=t-Bu) (Cp*=η5-C5Me5), by [PhNMe2H][B(C6F5)4] in chlorobenzene at −10 °C provides the cationic methallyl complexes, Cp*Zr(η3-C4H7)[N(R1)C(Me)N(R2)] (2a: R1=R2=i-Pr and 2b: R1=Et, R2=t-Bu), which are thermally robust in solution at elevated temperatures as determined by 1H NMR spectroscopy. Addition of B(C6F5)3 to 1a and 1b provides the zwitterionic allyl complexes, Cp*Zr{η3-CH2C[CH2B(C6F5)3]CH2}[N(R1)C(Me)N(R2)] (3a: R1=R2=i-Pr and 3b: R1=Et, R2=t-Bu). The crystal structures of 2b and 3a have been determined. Neither the cationic complexes 2 or the zwitterionic complexes 3 are active initiators for the Ziegler-Natta polymerization of ethylene and α-olefins. 相似文献
11.
The divalent europium bis-fluorenyl complex (C13H9)2Eu(THF)2 was synthesized by the metathesis reaction of EuI2(THF)2 with two equivalents of fluorenylpotassium and by the protolytic substitution of the naphthalene ligand in the (C10H8)Eu(THF)2 complex using the reaction with fluorene. According to X-ray diffraction data, the complex displays a skewed sandwich structure,
in which one fluorenyl ligand is η5-coordinated to the metal atom, whereas the η3-coordination mode makes a great contribution to the coordination of another ligand. The (C5Me4H)2YbI(THF) complex was synthesized by the reaction of YbI3(THF)2 with two equivalents of (C5Me4H)K. The structure of the complex was established by X-ray diffraction.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 530–534, March, 2008. 相似文献
12.
Juan Cámpora Pilar Palma Henk Kleijn Elisa Passaglia 《Journal of organometallic chemistry》2010,695(14):1794-1800
The catalytic activities of the highly fluorous systems formed by the zirconocene(IV) complexes [Zr{η5-C5H4SiMe2C2H4RF}2Cl2] (RF = C6F13 (4a), C10F21 (4b)) or [Zr-{η5-C5H3(SiMe2C2H4C6F13)2}2Cl2] (5a) and MMAO in toluene have been studied and compared with analogous nonfluorous systems generated from [Zr{η5-C5H4SiMe3}2Cl2] and [Zr{η5-C5H5}2Cl2]. Although less active than the reference systems, the fluorous catalysts are stable over prolonged polymerization times, giving rise to polymers with similar molecular weights to those obtained with [Zr{η5-C5H4SiMe3}2Cl2]. 相似文献
13.
Jian-Qiang Wang 《Journal of organometallic chemistry》2005,690(2):249-252
A trinuclear cluster {Cp*Ir[Se2C2(B10H10)]}2W(CO)2 (3) containing Ir-W bonding was obtained from the reaction of 16-electron complex Cp*Ir[Se2C2(B10H10)] with [W(CO)3(py)3] in the presence of BF3 · OEt2, and its structure has been determined by X-ray crystallography. 相似文献
14.
Shogo Sakai 《Journal of Molecular Structure》2001,540(1-3):157-169
The potential energy surfaces for reactions of ethylene with Cp2Ti+R, Cp2Ti(Cl)R, and Cp2Ti(Cl:AlH2Cl)R (R=H and CH3) were calculated by ab initio molecular orbital methods. These six reaction mechanisms were compared. Of the two possible reaction paths, attack of ethylene at Ti and the Cl and R ligands (path IN) and that from the opposite side of the Cl ligand (path OUT), the former is found to be more favorable, with a very low activation energy for reaction of ethylene with Cp2Ti(Cl)H. For reaction of ethylene with Cp2Ti(Cl)CH3, the insertion transition states on both paths have almost the same energy barrier height above the reactants. For reaction of ethylene with Cp2Ti(Cl:AlH2Cl)R, the bond alternation between Ti–Cl and Cl–Al plays an important role in the mechanisms. 相似文献
15.
Guofu Zi 《Journal of organometallic chemistry》2011,696(1):68-75
Group 4 metal complexes based on chiral biaryl ligands are readily prepared by a convenient amine elimination procedure, and they are efficient catalysts for the asymmetric hydroamination/cyclization of aminoalkenes. The biaryl-based ligands are highly modular enabling facile tuning of the catalyst reactivity and selectivity. The corresponding heterocyclic products have been obtained in excellent enantiomeric excesses (up to 93%) using sterically hindered C2-symmetric titanium and zirconium mesitoylamidate complexes such as [1,1′-(C10H10)2-2,2′-{NCO(2,4,6-Me3C6H2)}2]M(NMe2)2 (M = Ti, Zr). These results are presented in this short review. 相似文献
16.
Adam J. Davenport John Fawcett David R. Russell 《Journal of organometallic chemistry》2006,691(16):3445-3450
Condensation of mono N-substituted chiral ethylenediamines and pyridine-2-methoxyimidate gives new chiral pyridine imidazolines (1a-c). These react with [RuCl2(mes)]2 (mes = 1,3,5-trimethyl benzene) in the presence of NaSbF6 to give complexes [RuCl(L)(mes)][SbF6] (5a-c) which after treatment with AgSbF6 are enantioselective catalysts for the Diels-Alder reaction of methacrolein and cyclopentadiene. The imidazoline catalysts are less selective than the corresponding oxazoline ones. Compounds 1a, 5b and 5c have been characterised by X-ray crystallography. 相似文献
17.
Man Kin Tse Gopinathan Anilkumar Feyissa Gadissa Gelalcha 《Journal of organometallic chemistry》2006,691(21):4419-4433
Various Ru(L1)(L2) (1) complexes (L1 = 2,2′-bipyridines, 2,2′:6′,2″-terpyridines, 6-(4S)-4-phenyl-4,5-dihydro-oxazol-2-yl-2,2′-bipyridinyl or 2,2′-bipyridinyl-6-carboxylate; L2 = pyridine-2,6-dicarboxylate, pyridine-2-carboxylate or 2,2′-bipyridinyl-6-carboxylate) have been synthesized (or in situ generated) and tested on epoxidation of olefins utilizing 30% aqueous H2O2. The complexes containing pyridine-2,6-dicarboxylate show extraordinarily high catalytic activity. Based on the stereoselective performance of chiral ruthenium complexes containing non-racemic 2,2′-bipyridines including 6-[(4S)-4-phenyl-4,5-dihydro-oxazol-2-yl]-[2,2′]bipyridinyl new insights on the reaction intermediates and reaction pathway of the ruthenium-catalyzed enantioselective epoxidation are proposed. In addition, a simplified protocol for epoxidation of olefins using urea hydrogen peroxide complex as oxidizing agent has been developed. 相似文献
18.
K. O. Kallinen M. Ahlgr n T. T. Pakkanen T. A. Pakkanen 《Journal of organometallic chemistry》1996,510(1-2):37-43
The reaction between Ru3(CO)12 and a cyclic olefin (cis-cyclooctene or trans-cyclododecene) at 100 °C for several hours gives the title compounds (μ-H)2RU3(CO)9(μ3-η2-C8H12) (1), and (μ-H)RU3(CO)9(μ3-η3-C12H19) (2), both of which have been characterized by X-ray diffraction studies, IR and NMR spectral measurements and elemental analysis. The prolonged reaction between Ru3(CO)12 and cis-cyclooctene gives compound HRu3(CO)9(C8H11) (3). Compound 3 has been characterized with IR and NMR spectral analyses. In 1 the cyclooctene ring is linked via a μ3-η2-alkyne type of bonding to the face of the Ru3 cluster. It is formally σ-bonded to two of the three Ru atoms and π-bonded to the third Ru. The two hydrides in 1 are bridging Ru---Ru bonds. In 2 the cyclododecene ring is bonded to the Ru3 face via the μ3-η3-CCHC linkage. There are two formal σ-bonds from the allyl part to the hydrido-bridged Ru atoms and the η3-allyl linkage to the third Ru atom. 相似文献
19.
20.
Ka-Ho Tam 《Journal of organometallic chemistry》2007,692(21):4750-4759
An adaptable synthetic methodology for the tridentate dianionic pyridine-2-phenolate-6-aryl [O,N,C] ligand framework, comprising the aromatic σ-carbanion moiety as a chelating component, has been developed. A series of non-fluorinated group 4 bis(benzyl) complexes supported by [O,N,C] auxiliaries, with halogen and alkyl groups at the ‘R1’ position ortho to the metal-C(σ-aryl) bond, have been prepared by exploiting the cyclometalation of the ligand. All derivatives have been characterized by NMR spectroscopy, and the spectral features concerning the metal-bound diastereotopic methylene groups have been highlighted. The capabilities of these complexes as catalysts for olefin polymerization have been tested, and comparisons with the recently reported fluorine-containing Ti-[O,N,C] analogues and related Hf-[N,N,C] derivatives are discussed. The titanium catalysts, in conjunction with MAO, displayed moderate to high activities for ethylene polymerization (up to 200 g mmol−1 h−1). 相似文献