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1.
Reduction of isopropyldimethylsilyl-substituted titanocene dichloride [TiCl2(η5-C5Me4SiMe2Pri)2] (1) by excess magnesium in the presence of excess bis(trimethylsilyl)ethyne (btmse) in tetrahydrofuran at 60 °C yielded a mixture of products amongst them only the trinuclear Ti-Mg-Ti hydrido-bridged complex Mg[Ti(μ-H)2(η5-C5Me4SiMe2Pri)]2 (3) was isolated and characterized. The precursor of titanocene, [Ti(η5-C5Me4SiMe2Pri)2(η2-btmse)] (6), was obtained from the identical system which, after initial formation of [TiCl(η5-C5Me4SiMe2Pri)2] (2), reacted at −18 °C overnight and then the solution was rapidly separated from the remaining magnesium. Titanocene [Ti(η5-C5Me4SiMe2Pri)2] (7) was obtained by thermolysis of 6 at 75 °C in vacuum. Crystal structures of 1, 2, 3, 6, and 7 were determined. 相似文献
2.
The reaction of the tetramethylcyclopentadiene-silyl substituted derivative C5Me4(SiMe3)(SiMe2Cl) with MCl4 afforded the trichloro mono-tetramethylcyclopentadienyl complexes M(η5-C5Me4SiMe2Cl)Cl3 [M=Ti (1), Zr (2)] with selective elimination of SiMe3Cl. Compound 1 reacts with deoxygenated water in methylene chloride, with the evolution of HCl, to give the dinuclear titanium compound {Ti[μ-(η5-C5Me4SiMe2O-κO)]Cl2}2 (3), which was converted into the μ-oxo complex {Ti[μ-(η5-C5Me4SiMe2O-κO)]Cl}2(μ-O) (4) by a further hydrolysis reaction which occurred when a solution of 3 in toluene was refluxed for a long period of time in the air. Depending on the size of the alkyl ligand, reactions of the mononuclear compound 1 with an appropriate alkylating reagent rendered the peralkylated Ti(η5-C5Me4SiMe2R)R3 [R=Me (5), CH2Ph (6)] or partially alkylated {Ti[(η5-C5Me4SiMe2(CH2SiMe3)]Cl(CH2SiMe3)2} (7) compounds by a salt metathesis route. Attempts to synthesise a partially methylated or benzylated complex were unsuccessful. Treatment of the dinuclear compound 3 with four equivalents of MgClMe yielded the tetramethyl derivative {Ti[μ-(η5-C5Me4SiMe2O-κO)]Me2}2 (8), while the same reaction carried out with MgCl(CH2Ph) or Mg(CH2Ph)2·2THF gave the chloro-benzyl derivative {Ti[μ-(η5-C5Me4SiMe2O-κO)]Cl(CH2Ph)}2 (9) as an equimolar mixture of diastereomers, regardless of the molar ratio of the alkylating reagent used. All of the new compounds were characterised by elemental analysis and NMR spectroscopy. 相似文献
3.
Ji?í Pinkas Ana Conde Michal Horá?ek Karel Mach 《Journal of organometallic chemistry》2009,694(13):1971-2586
Elimination of methane during thermolysis of title compounds results in the formation of σ-Ti-C bond to t-butyl or benzyl group. The t-butyl-containing titanocene methyl compound [Ti(III)Me(η5-C5Me4t-Bu)2] (5) eliminates methane at 110 °C to give cleanly [Ti(III)(η5:η1-C5Me4CMe2CH2)(η5-C5Me4t-Bu)] (6). The methyl derivative of analogous benzyl-containing titanocene [Ti(III)Me(η5-C5Me4CH2Ph)2] was not isolated because it eliminated methane at ambient temperature to give [Ti(III)(η5:η1-C5Me4CH2-o-C6H4)(η5-C5Me4CH2Ph)] (7) with one phenyl ring linked to titanium atom in ortho-position. The corresponding titanocene dimethyl compound [TiMe2{η5-C5Me4t-Bu)}2] (9) eliminates two methane molecules at 110 °C to give the singly tucked-in 1,1-dimethylethane-1,2-diyl-tethered titanocene [Ti{η5:η1:η1-C5Me3(CH2)(CMe2CH2)}(η5-C5Me4t-Bu)] (11). In distinction, the analogous benzyl derivative [TiMe2(η5-C5Me4CH2Ph)2] (10) eliminates at 110 °C only one methane molecule to afford [TiMe(η5:η1-C5Me4CH2-o-C6H4)(η5-C5Me4CH2Ph)] (12) containing one phenyl group attached to titanium in o-position and one methyl group persisting on the titanium atom. This compound is stable at 150 °C for at least 3 h. The crystal structures of 5, 6, 7, and 10 were determined. 相似文献
4.
Sanjiv Prashar Mariano Fajardo Iván Dorado Antonio Otero 《Journal of organometallic chemistry》2004,689(7):1304-1314
The reactivity of dinuclear niobium and tantalum imido complexes with the isocyanide compound 2,6-Me2C6H3NC has been studied. The trialkyl complexes [{NbR3(CH3CN)}2(μ-1,3-NC6H4N)], [{NbR3(CH3CN)}2(μ-1,4-NC6H4N)] and [{TaR3(CH3CN)}2(μ-1,4-NC6H4N)] (R=CH2SiMe3) gave [{Nb(η2-RCNAr)2R}2(μ-1,3-NC6H4N)] (1), [{Nb(η2-RCNAr)2R}2(μ-1,4-NC6H4N)] (2) and [{Ta(η2-RCNAr)2R}2(μ-1,4-NC6H4N)] (3) (R=CH2SiMe3; Ar=2,6-Me2C6H3), from the isocyanide insertion in two of the metal alkyl carbon bonds. The reaction of the isocyanide reagent with the di-alkyl mono-cyclopentadienyl derivatives [{Nb(η5-C5H4SiMe3)R2}2(μ-1,3-NC6H4N)] (R=Me, CH2Ph, CH2SiMe3), [{Nb(η5-C5H4SiMe3)R2}2(μ-1,4-NC6H4N)] (R=Me, CH2Ph (4), CH2SiMe3) and [{Ta(η5-C5Me5)(CH2SiMe3)2}2(μ-1,4-NC6H4N)] yielded [{Nb(η5-C5H4SiMe3)(η2-RCNAr)R}2(μ-1,3-NC6H4N)] (R=Me (5), CH2Ph (6), CH2SiMe3 (7)), [{Nb(η5-C5H4SiMe3)(η2-RCNAr)R}2(μ-1,4-NC6H4N)] (R=Me (8), CH2Ph (9), CH2SiMe3 (10)) and [{Ta(η5-C5Me5)(η2-Me3SiCH2CNAr)CH2SiMe3}2(μ-1,4-NC6H4N)] (11) (Ar=2,6-Me2C6H3), respectively, from a single insertion process. The reaction with the mono-alkyl complex [{Nb(η5-C5H4SiMe3)(Me)Cl}2(μ-1,4-NC6H4N)] gave [{Nb(η5-C5H4SiMe3)(η2-MeCNAr)Cl}2(μ-1,4-NC6H4N)] (12), produced from the isocyanide insertion in the metal-alkyl carbon bond. The alkyl-amido complex [{Nb(η5-C5H4SiMe3)(Me)NMe2}2(μ-1,4-NC6H4N)] gave, from the preferential isocyanide insertion in the metal-amide nitrogen bond, [{Nb(η5-C5H4SiMe3)(η2-Me2NCNAr)Me}2(μ-1,4-NC6H4N)] (13). The molecular structure of one of the alkyl precursors, [{Nb(η5-C5H4SiMe3)(CH2Ph)2}2(μ-1,4-NC6H4N)] (4), has been determined. 相似文献
5.
Roy Buschbeck 《Journal of organometallic chemistry》2005,690(5):1198-1204
The synthesis of titanocenedichloride end-grafted carbosiloxane dendrimers of the 1st and 2nd generation is reported. To find the optimal reaction conditions, Me2ClSiH (1) was reacted with (η5-C5H4SiMe2CHCH2)(η5-C5H5)TiCl2 (2). The best result could be obtained with the Karstedt catalyst, whereby exclusively the β-isomer ((η5-C5H4SiMe2CH2CH2SiMe2Cl)(η5-C5H5)TiCl2, 3) is formed. Under similar conditions Me3SiOCH(Me)(CH2)4SiMe2H (4) reacts with 2 to give (η5-C5H4SiMe2CH2CH2SiMe2(CH2)4CH-(Me)OSiMe3)(η5-C5H5)TiCl2 (5). When using MeSi(OCH(Me)(CH2)4SiMe2H)3 (6), Si(OCH(Me)(CH2)4SiMe2H)4 (8) and MeSi[O(CH2)3SiMe(OCH(Me)(CH2)4SiMe2H)2]3 (10) instead of 1 and 4, the respective metallo dendrimers MeSi[OCH(Me)(CH2)4-SiMe2CH2CH2SiMe2(η5-C5H4)(η5-C5H5)TiCl2]3 (7), Si[OCH(Me)(CH2)4SiMe2CH2CH2SiMe2(η5-C5H4)(η5-C5H5)TiCl2]4 (9) and MeSi{O(CH2)3SiMe[OCH(Me)(CH2)4SiMe2CH2CH2SiMe2(η5- C5H4)(η5-C5H5)TiCl2]2}3 (11) can be isolated.Compounds 3, 5, 7, 9 and 11 were characterised by elemental analysis as well as IR and NMR spectroscopy (1H, 13C{1H}, 29Si{1H}). 相似文献
6.
Sergey A. Belov Dmitrii P. Krut’ko Dmitrii A. Lemenovskii Judith A.K. Howard 《Journal of organometallic chemistry》2008,693(10):1912-1918
Novel half-sandwich [C9H5(SiMe3)2]ZrCl3 (3) and sandwich [C9H5(SiMe3)2](C5Me4R)ZrCl2 (R = CH3 (1), CH2CH2NMe2 (2)) complexes were prepared and characterized. The reduction of 2 by Mg in THF lead to (η5-C9H5(SiMe3)2)[η5:η2(C,N)-C5Me4CH2CH2N(Me)CH2]ZrH (7). The structure of 7 was proved by NMR spectroscopy data. Hydrolysis of 2 resulted in the binuclear complex ([C5Me4CH2CH2NMe2]ZrCl2)2O (6). The crystal structures of 1 and 6 were established by X-ray diffraction analysis. 相似文献
7.
Antonio Antiñolo Mariano Fajardo Andrés Garcés Carmen López-Mardomingo Sanjiv Prashar 《Journal of organometallic chemistry》2006,691(7):1361-1368
The reaction of [1,4-{SiMe3(H)N}2C6Me4] (1) with 2 equivalents of LiBun followed by the addition of SiMe3Cl gave the diamine compound [1,4-{(SiMe3)2N}2C6Me4] (2). [Ta(η5-C5H4SiMe3)Cl4] reacts with 2, in a 2:1 stoichiometric ratio, to initially yield a mixture of the dinuclear, [{Ta(η5-C5H4SiMe3)Cl2}2(μ-1,4-NC6Me4N)] (3), and mononuclear, [Ta(η5-C5H4SiMe3)Cl2{NC6Me4-4-(N(SiMe3)2)}] (4), imido complexes. 3 can be obtained exclusively by submitting the reaction mixture to repeated cycles of evacuation, to remove volatiles, followed by addition of solvent and subsequent heating. The mononuclear imido complex 4 was isolated from the reaction of [Ta(η5-C5H4SiMe3)Cl4] with 2 in a 1:1 stoichiometric ratio. The molecular structure of 4 was determined by X-ray diffraction studies. [TaCl3(CH3CN)2{NC6Me4-4-(N(SiMe3)2)}] (5) has been prepared by the reaction of one molar equivalent of TaCl5 with 2 in a CH3CN/CH2Cl2 solvent mixture. The synthesis of the niobium complexes, [{Nb(η5-C5H4SiMe3)Cl2}2(μ-1,4-NC6Me4N)] (6) and [Nb(η5-C5H4SiMe3)Cl2{NC6Me4-4-(N(SiMe3)2)}] (7), was achieved in a similar manner to their tantalum analogues. The reactivity of 7 towards nucleophilic reagents, namely lithium benzamidinate, lithium (trimethylsilyl)cyclopentadienyl or lithium dimethylamide, has been studied and the following compounds prepared:[Nb(η5-C5H4SiMe3)RCl{NC6Me4-4-(N(SiMe3)2)}] (R = η5-C5H4SiMe3 (8), PhC(NSiMe3)2 (9), NMe2 (10)). In an attempt to form the hetero bimetallic complex, [{Nb(η5-C5H4SiMe3)Cl2}(μ-1,4-NC6Me4N){Ta(η5-C5H4SiMe3)Cl2}] (11), the reaction of 7 with [Ta(η5-C5H4SiMe3)Cl4] has been studied. Analysis of the reaction products showed that 11 may exist in equilibrium with the homo bimetallic complexes 3 and 6. 相似文献
8.
Manuel Gómez Pilar Gómez-Sal José Manuel Hernández 《Journal of organometallic chemistry》2007,692(11):2291-2298
Trichloro methyl [Nb{η5-C5H3(SiXMe2)(SiMe3)}Cl3Me] (X = Cl, 2; Me, 3), dichloro dimethyl [Nb{η5-C5H3(SiXMe2)(SiMe3)}Cl2Me2] (X = Cl, 4; Me, 5) and tetramethyl [Nb{η5-C5H3(SiXMe2)(SiMe3)}Me4] (X = Me, 6; Cl, 7) niobium complexes were synthesized by treatment of starting tetrachloro derivatives [Nb{η5-C5H3(SiXMe2)(SiMe3)}Cl4] (X = Cl, 1a; Me, 1b) with dimethyl zinc or chloro methyl magnesium in different proportions and conditions. A mixture of trichloro methyl and dichloro dimethyl tantalum complexes [Ta{η5-C5H3(SiClMe2)(SiMe3)}Cl4−xMex] (x = 1, 8; 2, 9) in a 2:1 molar ratio was obtained in the reaction of [Ta{η5-C5H3(SiClMe2)(SiMe3)}Cl4] (1c) with 0.5 equivalents of ZnMe2 in toluene at low temperature. 8 could be isolated as single compound when 1 equivalent of 1c was added to the mixtures of 8 and 9, while the reaction of 1c with 1.5 equivalents of dimethyl zinc gave 9 as unitary product. However, [Ta{η5-C5H3(SiMe3)2}Cl4] (1d) reacts with 0.5 equivalents of alkylating reagent giving the trichloro methyl compound [Ta{η5-C5H3(SiMe3)2}Cl3Me] (10) in good yield. On the other hand, [Ta{η5-C5H3(SiMe3)2}Cl4] (1d) reacts with 2 equivalents of MgClMe in hexane at room temperature giving a mixture of dichloro dimethyl and chloro trimethyl complexes[Ta{η5-C5H3(SiMe3)2}Cl4−xMex] (x = 2, 11; 3, 12), while the use of 4 equivalents of MgClMe converts 1c into the tetramethyl derivative [Ta{η5-C5H3(SiClMe2)(SiMe3)}Me4] (13). Finally, a tetramethyl tantalum complex [Ta{η5-C5H3(SiMe3)2}Me4] (14) was prepared by reaction of [Ta{η5-C5H3(SiXMe2)(SiMe3)}Cl4] (X = Cl, 1c; Me, 1d) with 5 (X = Cl) or 4 (X = Me) equivalents of MgClMe in diethyl ether (X = Cl) or hexane (X = Me), respectively, as solvent. All the complexes were studied by IR and NMR spectroscopy and the molecular structure of the complex 11 was determined by X-ray diffraction methods. 相似文献
9.
Michal Horá?ek Ji?í Kubišta Kai Dallmann Karel Mach 《Journal of organometallic chemistry》2004,689(24):4592-4600
Paramagnetic titanocene complexes containing the unsaturated carbyl group which consists of one and half molecule of 1,4-bis(trimethylsilyl)buta-1,3-diyne (BSD) are formed by the reduction of titanocene dichlorides with one molar equivalent of magnesium in the presence of 1.5 molar equivalent BSD in tetrahydrofuran (THF) for titanocene moieties Ti(η5-C5H5 − nMen)2 (n = 5 (1), 4 (2), and 3 (3)) and Ti{Me2Si(η5-C5Me4)2} (4). The non-methylated titanocene moiety affords under identical conditions known diamagnetic bis(η5-cyclopentadienyl)-2,4-bis(trimethylsilylethynyl)-3,5-bis(trimethylsilyl)titanacyclopenta-2,4-diene (5) as the major product. Crystal structures of 3 and 4 show the same bonding scheme for the 1,4,6-tris(trimethylsilyl)hex-3-ene-1,5-diyne-3-yl ligand as previously found for compound 1 [P.-M. Pellny, F.G. Kirchbauer, V.V. Burlakov, A. Spannenberg, K. Mach, U. Rosenthal, Chem. Commun. (1999) 2505]. Compound 1 is stable against weak proton donors like methanol or alk-1-ynes even at 90 °C, however, it undergoes retroreaction when oxidized by PbCl2 in THF, yielding nearly quantitatively BSD and [TiCl2(η5-C5Me5)2]. 相似文献
10.
New half-sandwich titanocene complexes (η5-C5Me5)Ti(OC6F5)3 (1), (η5-C5Me5)Ti(OCH2C6F5)3 (2), and (η5-C5Me5)Ti(OCH2C6F2H3)3 (3) were synthesized via the displacement of methoxide ligands in (η5-C5Me5)Ti(OMe)3 by the corresponding aryloxy or benzyloxy ligands. These compounds have been fully characterized by various spectroscopic methods including X-ray crystallography. Compound 1 has a distorted three-legged piano stool structure. However, complexes 2 and 3 have the chariot-like structure, where chariot means a two-wheeled horse-drawn vehicle. The π electron donation of oxygen atom to Ti center in complexes 1-3 is considerable. 相似文献
11.
Alexander Hildebrandt 《Journal of organometallic chemistry》2011,696(20):3231-3237
The synthesis and properties of heterobimetallic Ti-M complexes of type {[[Ti](μ-η1:η2-CCSiMe3)][M(μ-η1:η2-CCSiMe3)(CO)4]} (M = Mo: 5, [Ti] = (η5-C5H5)2Ti; 6, [Ti] = (η5-C5H4SiMe3)2Ti; M = W: 7, [Ti] = (η5-C5H5)2Ti; 8, [Ti] = (η5-C5H4SiMe3)2Ti) and {[Ti](μ-η1:η2-CCSiMe3)2}MO2 (M = Mo: 13, [Ti] = (η5-C5H5)2Ti; 14, [Ti] = (η5-C5H4SiMe3)2Ti). M = W: 15, [Ti] = (η5-C5H5)2Ti; 16, [Ti] = (η5-C5H4SiMe3)2Ti) are reported. Compounds 5-8 were accessible by treatment of [Ti](CCSiMe3)2 (1, [Ti] = (η5-C5H5)2Ti; 2, [Ti] = (η5-C5H4SiMe3)2Ti) with [M(CO)5(thf)] (3, M = Mo; 4, M = W) or [M(CO)4(nbd)] (9, M = Mo; 10, M = W; nbd = bicyclo[2.2.1]hepta-2,5-diene), while 13-16 could be obtained either by the subsequent reaction of 1 and 2 with [M(CO)3(MeCN)3] (11, M = Mo; 12, M = W) and oxygen, or directly by oxidation of 5-8 with air. A mechanism for the formation of 5-8 is postulated based on the in-situ generation of [Ti](CCSiMe3)((η2-CCSiMe3)M(CO)5), {[Ti](μ-η1:η2-CCSiMe3)2}-M(CO)4, and [Ti](μ-η1:η2-CCSiMe3)((μ-CCSiMe3)M(CO)4) as a result of the chelating effect exerted by the bis(alkynyl) titanocene fragment and the steric constraints imposed by the M(CO)4 entity.The molecular structure of 5 in the solid state were determined by single crystal X-ray diffraction analysis. In doubly alkynyl-bridged 5 the alkynides are bridging the metals Ti and Mo as a σ-donor to one metal and as a π-donor to the other with the [Ti](CCSiMe3)2Mo core being planar. 相似文献
12.
Santiago Gómez-Ruiz Beatriz Gallego Željko Žižak Evamarie Hey-Hawkins Zorica D. Juranić Goran N. Kaluđerović 《Polyhedron》2010
Four titanium(IV) carboxylate complexes [Ti(η5-C5H5)2(O2CCH2SMes)2] (1), [Ti(η5-C5H4Me)2(O2CCH2SMes)2] (2), [Ti(η5-C5H5)(η5-C5H4SiMe3)(O2CCH2SMes)2] (3) and [Ti(η5-C5Me5)(O2CCH2SMes)3] (4; Mes = 2,4,6-Me3C6H2) have been synthesised by the reaction of the corresponding titanium derivatives [Ti(η5-C5H5)2Cl2], [Ti(η5-C5H4Me)2Cl2], [Ti(η5-C5H5)(η5-C5H4SiMe3)Cl2] and [Ti(η5-C5Me5)Cl3] and two (for 1–3) or three (for 4) equivalents of mesitylthioacetic acid. Complexes 1–4 have been characterized by spectroscopic methods and the molecular structure of the complexes 1, 2 and 4 have been determined by X-ray diffraction studies. The cytotoxic activity of 1–4 was tested against tumor cell lines human adenocarcinoma HeLa, human myelogenous leukemia K562, human malignant melanoma Fem-x, and normal immunocompetent cells, that is peripheral blood mononuclear cells PBMC and compared with those of the reference complexes [Ti(η5-C5H5)2Cl2] (R1), [Ti(η5-C5H4Me)2Cl2] (R2), [Ti(η5-C5H5)(η5-C5H4SiMe3)Cl2] (R3) and cisplatin. In all cases, the cytotoxic activity of the carboxylate derivatives was higher than that of their corresponding dichloride analogues, indicating a positive effect of the carboxylato ligand on the final anticancer activity. Complexes 1–4 are more active against K562 (IC50 values from 72.2 to 87.9 μM) than against HeLa (IC50 values from 107.2 to 142.2 μM) and Fem-x cells (IC50 values from 90.2 to 191.4 μM). 相似文献
13.
Jiří Pinkas Ivana Císařová Róbert Gyepes Jiří Kubišta Karel Mach Michal Horáček 《Transition Metal Chemistry》2016,41(2):143-152
Bis{(diphenylvinylsilyl)tetramethylcyclopentadienyl}titanium dichloride [TiCl2{η5-C5Me4(SiPh2CH=CH2)}2] (1) is reduced with a half molar equivalent of magnesium to the monochloride ([TiCl{η5-C5Me4(SiPh2CH=CH2)}2] (2), whereas one molar equivalent of magnesium affords the titanocene [Ti{η5-C5Me4(SiPh2CH=CH2)}{η5:η2-C5Me4(SiPh2CH=CH2)}] (3) stabilized by η2-coordination of one of the two vinyl groups to titanium(II). In the presence of excess magnesium, the vinyl moieties of 3 undergo intramolecular coupling to afford the ansa-titanocene [Ti(η5:η5:η2-C5Me4SiPh2CH=CHCH2CH2SiPh2C5Me4)] (4) possessing the η2-coordinated double bond in lateral position of its ansa-chain. The symmetrical ansa-titanocene [Ti(η5:η5:η2-C5Me4SiPh2CH2CH=CHCH2SiPh2C5Me4)] (5) was not obtained although its DFT-calculated energy is only slightly higher than that of 4. It is considered that transient 5 gives rise to non-identified tar-like by-products which inherently accompany the formation of 4. 相似文献
14.
Chlorosilyl-cyclopentadienyl titanium precursors [Ti(η5-C5Me4SiMeXCl)Cl3] (X=H 2, Cl 3) were prepared by reaction of TiCl4 with the trimethylsilyl derivatives of the corresponding cyclopentadienes. Methylation of these compounds with MgClMe under appropriate conditions afforded the methyl complexes [Ti(η5-C5Me4SiMe2R)XMe2] (R=H, X=Cl 5, Me 6; R=X=Me 7). Reactions of 2 and 3 with two equivalents of LiNHtBu afforded the ansa-silyl-η-amido compounds [Ti{η5-C5Me4SiMeX(η1-NtBu)}Cl2] (X=H 8, Cl 9). Methylation of 8 gave [Ti{η5-C5Me4SiMeH(η1-NtBu)}Me2] 10. Complex 9 was also obtained by reaction of 8 with BCl3, whereas the same reaction using alternative chlorinating agents (TiCl4, HCl) resulted in deamidation to give 2, which was also converted into 3 by reaction with BCl3. All of the new compounds were characterized by NMR spectroscopy and the molecular structures of 2 and 4 were determined by X-ray diffraction methods. 相似文献
15.
Hisako Hashimoto Kazuyoshi Kurashima Hiroshi Ogino 《Journal of organometallic chemistry》2004,689(9):1481-1495
A phosphido-bridged unsymmetrical diiron complex (η5-C5Me5)Fe2(CO)4(μ-CO)(μ-PPh2) (1) was synthesized by a new convenient method; photo-dissociation of a CO ligand from (η5-C5Me5)Fe2(CO)6(μ-PPh2) (2) that was prepared by the reaction of Li[Fe(CO)4PPh2] with (η5-C5Me5)Fe(CO)2I. The reactivity of 1 toward various alkynes was studied. The reaction of 1 with tBuCCH gave a 1:1 mixture of two isomeric complexes (η5-C5Me5)Fe2(CO)3(μ-PPh2)[μ-CHC(tBu)C(O)] (3) containing a ketoalkenyl ligand. The reactions of 1 with other terminal alkynes RCCH (R=H, CO2Me, Ph) afforded complexes incorporating one or two molecules of alkynes and a carbonyl group. The principal products were dinuclear complexes bridged by a new phosphinoketoalkenyl ligand, (η5-C5Me5)Fe2(CO)3(μ-CO)[μ-CR1CR2C(O)PPh2] (4a: R1=H, R2=H; 4b: R1=CO2Me, R2=H; 4c: R1=H, R2=Ph). In the cases of alkynes RCCH (R=H, CO2Me), dinuclear complexes having a new ligand composed of two molecules of alkynes, a carbonyl group, and a phosphido group; i.e. (η5-C5Me5)Fe2(CO)3[μ-CRCHCHCRC(O)PPh2] (5a: R=H; 5b: R=CO2Me), were also obtained. In all cases, mononuclear complexes, (η5-C5Me5)Fe(CO)[CR1CR2C(O)PPh2] (6a: R1=H, R2=H; 6b: R1=H, R2=CO2Me; 6c: R1=H, R2=Ph) were isolated in low yields. The structures of 1, 4c, 5b, and 6a were confirmed by X-ray crystallography. The detailed structures of the products and plausible reaction mechanisms are discussed. 相似文献
16.
Michal Horá?ek Ivana Císa?ová Ji?í Pinkas 《Journal of organometallic chemistry》2010,695(21):2338-1045
The singly tucked-in titanocene [Ti(η5-C5Me5)(η5:η1-C5Me4CH2)] (1) reacts smoothly with ethylene glycol or hydroquinone to give bis(titanoceneoxide) (TiIII) complexes [CH2OTi(η5-C5Me5)2]2 (2) and [(η5-C5Me5)2TiOC6H4OTi(η5-C5Me5)2] (3) containing dimethylene and 1,4-phenylene link, respectively. EPR spectra of 2 in 2-methyltetrahydrofuran glass and 3 in toluene glass revealed that the unpaired d1 electrons are in interaction to form triplet state molecules. The Ti-Ti distance derived from the zero-field splittings D for the two conformations of 2 (7.42 Å and 7.66 Å) are in good agreement with the Ti-Ti distance of 7.2430(7) Å from the X-ray diffraction single-crystal analysis. For 3, however, the Ti-Ti distance derived from D (7.65 Å) is by 1.47 Å shorter than the crystallographic distance of 9.1230(8) Å that indicates an enhancement of the through-space dipole-dipole interaction due to the presence of a conjugated quinonide link. 相似文献
17.
Santiago Gómez-Ruiz Jesús Ceballos-Torres Mariano Fajardo Zorica D. Jurani? 《Journal of organometallic chemistry》2011,696(20):3206-3213
The reaction of 2,6-dimethoxypyridine-3-carboxylic acid (DMPH) with different precursors [Ti(η5-C5H5)2Cl2], [Ti(η5-C5H4Me)2Cl2], [Ti(η5-C5H4SiMe3)(η5-C5H5)Cl2], [Ti(η5-C5Me5)Cl3], SnMe3Cl and GatBu3 yielded the complexes [Ti(η5-C5H5)2(DMP-κO)2] (1), [Ti(η5-C5H4Me)2(DMP-κO)2] (2), [Ti(η5-C5H4SiMe3)(η5-C5H5)(DMP-κO)2] (3), [Ti(η5-C5Me5)(DMP-κ2O,O′)3] (4), [SnMe3(μ-DMP-κO:κO′)]∞ (5), and [GatBu2(μ-DMP-κO:κO′)]2 (6). 1-6 have been characterized by spectroscopic methods and the molecular structure of the complexes 1, 2, 3, 5 and 6 have been determined by X-ray diffraction studies. The cytotoxic activity of 1-6 was tested against the tumour cell lines human adenocarcinoma HeLa, human myelogenous leukaemia K562, human malignant melanoma Fem-x and human breast carcinoma MDA-MB-361. The results of this study show a higher cytotoxicity of the tin(IV) and gallium(III) derivatives in comparison to their titanium(IV) counterparts. Furthermore, the different titanium compounds showed differences in their cytotoxicities with a higher activity of complex 4 (mono-(cyclopentadienyl) derivative) compared to that of 1-3 (bis-(cyclopentadienyl) complexes). A qualitative UV-vis study of the interactions of these complexes with DNA has also been carried out. 相似文献
18.
Dmitrii P. Krut’ko Roman S. Kirsanov Maxim V. Borzov Andrei V. Churakov 《Journal of organometallic chemistry》2007,692(7):1465-1471
Half-sandwich [η5:η1-κN-C5Me4CH2-(2-C5H4N)]MCl3 (M = Ti (4), Zr (5)) and sandwich [η5-C5Me4CH2-(2-C5H4N)][η5-C5Me5]ZrCl2 (6) ring-peralkylated complexes have been prepared and characterized. Evidence of the intramolecular coordination of the side-chain pyridyl group both in 4 and 5 in solutions is provided by NMR spectroscopy data. Crystal structure of an adduct 5-py with one molecule of pyridine has been established by X-ray diffraction analysis. 相似文献
19.
Véronique Plantevin 《Journal of organometallic chemistry》2004,689(11):2013-2024
Further investigations into the chemistry of the rhenacyclobutadiene complexes (CO)4Re(η2-C(R)C(CO2Me)C(X)) (1: R=Me, X=OEt (1a), O(CH2)3CCH (1b), NEt2 (1c); R=CHEt2, X=OEt (1d); R=Ph, X=OEt (1e)) are reported. Reactions of 1 with alkynes at reflux temperature of toluene and at ambient temperature either under photochemical conditions or in the presence of PdO yield ring-substituted η5-cyclopentadienylrhenium tricarbonyl complexes, 2. The symmetrical alkynes R′CCR′ (R′=Ph, Me, CO2Me) afford the pentasubstituted complexes (η5-C5(Me)(CO2Me)(OEt)(Ph)(Ph))Re(CO)3 (2d), (η5-C5(Me)(CO2Me)(OEt)(Me)(Me))Re(CO)3 (2e), (η5-C5(Me)(CO2Me)(OEt)(CO2Me)(CO2Me))Re(CO)3 (2f), and (η5-C5(Me)(CO2Me)(NEt2)(CO2Me)(CO2Me))Re(CO)3 (2i) on reaction with the appropriate 1, whereas the unsymmetrical alkynes R′CCR″ (R′=Ph; R″=H, Me) give either only one, (η5-C5(Me)(CO2Me)(OEt)(Ph)H)Re(CO)3 (2a)), or both, (η5-C5(Me)(CO2Me) (OEt)(Ph)(Me))Re(CO)3 (2b) and (η5-C5(Me)(CO2Me)(OEt)(Me)(Ph))Re(CO)3 (2c), (η5-C5(Ph)(CO2Me)(OEt)(Ph)H)Re(CO)3 (2g) and (η5-C5(Ph)(CO2Me)(OEt)(H)(Ph))Re(CO)3 (2h), of the possible products of [3 + 2] cycloaddition of alkyne to η2-C(R)C(CO2Me)C(X). Thermolysis of (CO)4Re(η2-C(Me)C(CO2Me)C(O(CH2)3CCH)) (1b) containing a pendant alkynyl group proceeds to (η5-C5(Me)(CO2Me)(O(CH2)3)H)Re(CO)3 (2j), a η5-cyclopentadienyl-dihydropyran fused-ring product. Competition experiments showed that each of PhCCH and MeO2CCCCO2Me reacts faster than PhCCPh with 1a. The results with unsymmetrical alkynes are rationalized by steric properties of substituents at the CC and ReC bonds and by a preference of ReC(Me) over ReC(OEt) to undergo alkyne insertion. A mechanism is proposed that involves substitution of a trans CO by alkyne in 1, insertion of alkyne into ReC bond to give a rhenabenzene intermediate, and collapse of the latter to 2. Complexes 1a and 1d undergo rearrangement in MeCN at reflux temperature to give rhenafuran-like products, (CO)4Re(κ2-OC(OMe)C(CHCR2)C(OEt)) (R=H (3a) or Et (3b)). The reaction of 1d also proceeds in EtCN, PhCN, and t-BuCN at comparable temperature, but is slower (especially in t-BuCN) than in MeCN. In pyridine at reflux temperature, 1a undergoes a similar rearrangement, with CO substitution, to give (CO)3(py)Re(κ2-OC(OMe)C(CHCEt2)C(OEt)) (4). A mechanism is proposed for these reactions. The sulfonium ylides Me2SCHC(O)Ph and Me2SC(CN)2 (Me2SCRR′) react with 1a in acetonitrile at reflux temperature by nucleophilic addition of the ylide to the ReC(Me) carbon, loss of Me2S, and rearrangement to a rhenafuran-type structure to yield (CO)4Re(κ2-OC(OMe)C(C(Me)CRR′)C(OEt)) (R=H, R′=C(O)Ph (5a); R=R′CN (5b)). All new compounds were characterized by a combination of elemental analysis, mass spectrometry, and IR and NMR spectroscopy. 相似文献
20.
Wei Miao Shihui Li Hongxia Zhang Yurong Wang 《Journal of organometallic chemistry》2007,692(22):4828-4834
Treatment of yttrium tris(alkyl)s, Y(CH2SiMe3)3(THF)2, by equimolar H(C5Me4)SiMe3(HCp′) and indene (Ind-H) afforded (η5-Cp′)Y(CH2SiMe3)2(THF) (1) and (η5-Ind)Y(CH2SiMe3)2(THF) (2) via alkane elimination, respectively. Complex 1 reacted with methoxyamino phenols, 4,6-(CH3)2-2-[(MeOCH2CH2)2-NCH2]-C6H2-OH (HL1) and 4,6-(CMe3)2-2-[(MeOCH2CH2)2-NCH2]-C6H2-OH (HL2) gave mixed ligands supported alkyl complexes [(η5-Cp′)(L)]Y(CH2SiMe3) (3: L = L1; 4: L = L2). Whilst, complex 2 was treated with HL2 to yield [(η5-Ind)(L2)]Y(CH2SiMe3) (5). The molecular structures of 3 and 5 were confirmed by X-ray diffraction to be mono(alkyl)s of THF-free, adopting pyramidal and tetragonal-bipyramidal geometry, respectively. Complexes 3 and 5 were high active initiators for the ring-opening polymerization of l-lactide to give isotactic polylactide with high molecular weight and narrow to moderate polydispersity. 相似文献