共查询到20条相似文献,搜索用时 31 毫秒
1.
Paul Binger Patrik Müller Petra Philipps Barbara Gabor Richard Mynott Albert T. Herrmann Franz Langhauser Carl Krüger 《欧洲无机化学杂志》1992,125(10):2209-2212
Bis(trimethylphosphane)titanocene ( 1 ) reacts with 2-methylene-1,1-diphenylcyclopropane ( 2 ) to give red crystalline (η2-2-methylene-1,1-diphenylcyclopropane)(trimethylphosphane)titanocene ( 3 ). In solution complex 3 degrades smoothly to form the new Cp2Ti(PMe3) – C2 – Ti(PMe3)Cp2 complex 4 , the crystal structure of which has been elucidated by an X-ray analysis. 相似文献
2.
Martin Ruhmann Anke Spannenberg Alexander Villinger Axel Schulz Torsten Beweries 《无机化学与普通化学杂志》2013,639(10):1717-1721
The titanocene bis(trimethylsilyl)acetylene complex Cp2Ti(η2‐Me3SiC2SiMe3) ( 1 ) reacts with different triazines to give trinuclear titanocene compounds. Cleavage of the heterocyclic unit takes place in the reaction with cyanuric chloride, which furnishes a trinuclear cyanide bridged titanocene complex [Cp2Ti(CN)]3 ( 2 ). Reaction with cyanuric acid yields the paramagnetic ate complex (Cp2Ti)3(C3N3O3) ( 3 ). With melamine the structurally similar amide species (Cp2Ti)3[C3N3(NH)3] ( 4 ) is formed. A dinuclear, paramagnetic complex 5 is obtained in the reaction of 1 with dicyandiamide. Complexes 2 , 4 , and 5 were characterized by X‐ray analyses. 相似文献
3.
G.A. Razuvaev V.N. Latyaeva L.I. Vishinskaya V.T. Bytchkov G.A. Vasilyeva 《Journal of organometallic chemistry》1975,87(1):93-99
The reaction of dicyclopentadienyltitanium dichloride with bis(triethylgermyl)mercury in benzene solution at 20° yields metallic mercury quantitatively, titanocene monochloride and triethylchlorogermane. The reaction of dicyclopentadienyltitanium dichloride with bis(triethylgermyl)cadmium leads to the formation of a complex of the following general composition: [Cp2TiCl2 - Cd(GeEt3)2]. The reactivity of this complex has been studied: in toluene solution at 20° it decomposes slowly to yield metallic cadmium, triethylchlorogermane and Cp2TiCl(GeEt3). 相似文献
4.
Jan Honzí?ek Jaromír Vinklárek Lukáš St?i?ík Zdeňka Padělková 《Journal of organometallic chemistry》2009,694(26):4250-3467
The new titanocene and vanadocene complexes of the non-linear pseudohalides Cp2Ti(dcmb)2, Cp2VCl(dcmb), (η5-C5H4Me)2VCl(dcmb) and Cp2V(dcmb)2 were prepared by reaction of titanocene dichloride (Cp2TiCl2) and vanadocene dichlorides (Cp2VCl2, (η5-C5H4Me)2VCl2) with dicyanomethanidobenzoic acid (dcmbH, PhC(OH)C(CN)2). These reactions have proven that the dcmb ligand could be coordinated to the central metal by oxygen or nitrogen donor atoms. The bonding mode of the dcmb ligand reflects properties of the central metal. The strongly oxophilic titanium(IV) shows the bonding through oxygen atom while bonding through nitrogen atom was observed for less oxophilic vanadium(IV). The bonding fashion of the dcmb ligands was determined by spectroscopic methods. X-ray diffraction analysis was used for the structure determination of the compounds dcmbH·H2O, Cp2Ti(dcmb)2·CH2Cl2, (η5-C5H4Me)2VCl(dcmb) and [Cp2V(OC(Ph)C(CN)C(OMe)NH)][dcmb]. 相似文献
5.
Tomohiro Shono 《Tetrahedron letters》2006,47(8):1257-1260
Titanocene alkenylidene complexes, generated by the reductive metallation of 1,1-dichloro-1-alkenes with the titanocene(II) species Cp2Ti[P(OEt)3]2, reacted with alkynes to produce conjugated dienes. 相似文献
6.
Jürgen Schellenberg 《Journal of polymer science. Part A, Polymer chemistry》2000,38(13):2428-2439
The syndiospecific polymerization of styrene was investigated with the fluorine‐containing half‐sandwich complexes η5‐pentamethylcyclopentadienyl titanium bis(trifluoroacetate) dimer, η5‐octahydrofluorenyl titanium tristrifluoro‐acetate, η5‐octahydrofluorenyl titanium dimethoxymonotrifluoroacetate, and η5‐octahydrofluorenyl titanium tris(pentafluorobenzoate) in comparison to known chloride and methoxide complexes in the presence of relatively low amounts of methylalumoxane and triisobutylaluminum. After the selection of effective reaction conditions for a solvent‐free polymerization, the following orders of decreasing polymerization activity of the titanium complexes can be observed: for pentamethylcyclopentadienyl compounds, Cp*Ti(OMe)3 > [Cp*Ti(OCOCF3)2]2O ≈ Cp*TiCl3, and for octahydrofluorenyl compounds, [656]Ti(OMe)3 > [656]Ti(OCOC6F5)3 > [656]Ti(OCH3)2(OCOCF3) > [656]Ti (OCOCF3)3. The [656]Ti complexes, showing the highest polymerization conversions at 70 °C and in comparison with the Cp* Ti compounds, turned out to be highly efficient catalysts for the syndiospecific styrene polymerization. The fluorine‐containing Cp* and [656]Ti complexes lead to much higher molecular weights than the chloride and methoxide compounds because of a reduction in chain‐limiting transfer reactions. The introduction of only one fluorine‐containing ligand into the coordination sphere of the metal compound is obviously sufficient for a significant increase in molecular weight. The active polymerization sites of the [656]Ti complexes with methylalumoxane and triisobutylaluminum are extremely stable during storage at room temperature in regard to their polymerization activity. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 2428–2439, 2000 相似文献
7.
Highly Strained Heterometallacycles of Group 4 Metallocenes with Bis(diphenylphosphino)amide Ligands
Martin Haehnel Sven Hansen Dr. Anke Spannenberg Dr. Perdita Arndt Dr. Torsten Beweries Prof. Dr. Uwe Rosenthal 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(34):10546-10553
A study regarding coordination chemistry of the bis(diphenylphosphino)amide ligand Ph2P‐N‐PPh2 at Group 4 metallocenes is presented herein. Coordination of N,N‐bis(diphenylphosphino)amine ( 1 ) to [(Cp2TiCl)2] (Cp=η5‐cyclopentadienyl) generated [Cp2Ti(Cl)P(Ph2)N(H)PPh2] ( 2 ). The heterometallacyclic complex [Cp2Ti(κ2‐P,P‐Ph2P‐N‐PPh2)] ( 3 Ti ) can be prepared by reaction of 2 with n‐butyllithium as well as from the reaction of the known titanocene–alkyne complex [Cp2Ti(η2‐Me3SiC2SiMe3)] with the amine 1 . Reactions of the lithium amide [(thf)3Li{N(PPh2)2}] with [Cp2MCl2] (M=Zr, Hf) yielded the corresponding zirconocene and hafnocene complexes [Cp2M(Cl){κ2‐N,P‐N(PPh2)2}] ( 4 Zr and 4 Hf ). Reduction of 4 Zr with magnesium gave the highly strained heterometallacycle [Cp2Zr(κ2‐P,P‐Ph2P‐N‐PPh2)] ( 3 Zr ). Complexes 2 , 3 Ti , 4 Hf , and 3 Zr were characterized by X‐ray crystallography. The structures and bondings of all complexes were investigated by DFT calculations. 相似文献
8.
The reaction of titanocene dichloride,Cp
2TiCl2 (Cp=5-C5H5), with one or two equivalents of sodium cyanodithioformate affords the new mono- or bis(dithiocarboxylato) derivativesCp
2TiCl(S2CCN) (1) andCp
2Ti(S2CCN)2 (2). Elimination of sulfur converts2 into the metallacyclicCp
2TiS2C2(CN)2 (3), which does not react with the diene isoprene, but can be reconverted into the appropriate titanocene dihalides by chlorine or bromine. 相似文献
9.
《Journal of organometallic chemistry》1987,320(1):37-45
The reduction of Cp2MCl2 (M = Ti, Zr) with magnesium in THF in the presence of PMe3 affords the complexes Cp2M(PMe3)2 in high yields. These compounds lose one or both PMe3 ligands under very mild conditions. Cp2Ti(PMe3)2 reacts readily with CH3I, CH3C(O)Cl, PhSSPh, Me2PCH2CH2PMe2, CO, RCN (R = Me, t-Bu) or (RN)2S (R = t-Bu, Me3Si) to give the corresponding titanocene products. The structure of Cp2Zr(PMe3)2 has been determined by X-ray diffraction; the structural parameters are similar to those of the titanium analog Cp2Ti(PMe3)2 except that the Zr-P and Zr-C distances are longer. 相似文献
10.
Air-stable titanocene bis(perfluorooctanesulfonate) [Cp2Ti(OSO2C8F17)2] that shows high Lewis acidity was prepared from Cp2TiCl2 and AgOSO2C8F17. The compound was characterized by different techniques, and examined as a catalyst for acylation reactions. It was found that using equimolar acetic anhydride as acetylating agent and under solvent-free condition, Cp2Ti(OSO2C8F17)2 exhibits high activity and selectivity in the acetylation of various alcohols, phenols, thiols, and amines. Also, good catalytic efficiency is observed in the acylation of 2-phenylethanol across various acylating reagents. The catalyst can be reused without loss of activity in a test of ten cycles. The Cp2Ti(OSO2C8F17)2 catalyst affords a simple, efficient and general method for the acylation of alcohols, phenols, thiols, and amines. 相似文献
11.
The oxidation elimination reaction between dicarbonyl titanocene and aryltin halides was studied by means of paramagnetic resonance spectroscopy. The radical intermediates containing Ti(III) were discovered from the ESR spectra to be (Cp2TiSnArnX3-n), Cp2Ti(CO)X, and Cp2TiX, and a radical mechanism for the reaction is proposed. © 1996 John Wiley & Sons, Inc. 相似文献
12.
《Polyhedron》1988,7(13):1221-1223
Reaction of titanocene dichloride with two equivalents of silver hexafluoroantimonate in sulphur dioxide quantitatively yields Cp2Ti(SbF6)2 (Cp = η5-C5H5) and AgCl. The titanocene bishexafluoroantimonate was recrystallized from SO2 and characterized by chemical analysis, 1H NMR, IR and mass spectroscopy. 相似文献
13.
《Mendeleev Communications》2022,32(2):212-214
The compound Na2Ti(CF3COO)6(CF3COOH)2 was synthesized as colorless crystals, extremely unstable in air, by the reaction of TiCl4 with trifluoroacetic acid and sodium trifluoroacetate. Crystallographic studies have shown that this sodium trifluoroacetatotitanate is the first example of a tetravalent titanium carboxylate [Ti(RCOO)6]2– containing titanium in an octahedral environment of oxygen atoms of carboxylate groups. Thermal decomposition of Na2Ti(CF3COO)6(CF3COOH)2 in an argon atmosphere results in the complex fluoride Na2TiF6. 相似文献
14.
Dr. Katharina Kaleta Frank Strehler Dr. Alexander Hildebrandt Dr. Torsten Beweries Dr. Perdita Arndt Dr. Tobias Rüffer Dr. Anke Spannenberg Prof. Dr. Heinrich Lang Prof. Dr. Uwe Rosenthal 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(40):12672-12680
The reaction of different metallocene fragments [Cp2M] (Cp=η5‐cyclopentadienyl, M=Ti, Zr) with diferrocenylacetylene and 1,4‐diferrocenylbuta‐1,3‐diyne is described. The titanocene complexes form the highly strained three‐ and five‐membered ring systems [Cp2Ti(η2‐FcC2Fc)] ( 1 ) and [Cp2Ti(η4‐FcC4Fc)] ( 2 ) (Fc=[Fe(η5‐C5H4)(η5‐C5H5)]) by addition of the appropriate alkyne or diyne to Cp2Ti. Zirconocene precursors react with diferrocenyl‐ and ferrocenylphenylacetylene under C? C bond coupling to yield the metallacyclopentadienes [Cp2Zr(C4Fc4)] ( 3 ) and [Cp2Zr(C4Fc2Ph2)] ( 5 ), respectively. The exchange of the zirconocene unit in 3 by hydrogen atoms opens the route to the super‐crowded ferrocenyl‐substituted compound tetraferrocenylbutadiene ( 4 ). On the other hand, the reaction of 1,4‐diferrocenylbuta‐1,3‐diyne with zirconocene complexes afforded a cleavage of the central C? C bond, and thus, dinuclear [{Cp2Zr(μ‐η1:η2‐C?CFc)}2] ( 6 ) that consists of two zirconocene acetylide groups was formed. Most of the complexes were characterized by single‐crystal X‐ray crystallography, showing attractive multinuclear molecules. The redox properties of 3 , 5 , and 6 were studied by cyclic voltammetry. Upon oxidation to 3 n+, 5 n+, and 6 n+ (n=1–3), decomposition occured with in situ formation of new species. The follow‐up products from 3 and 5 possess two or four reversible redox events pointing to butadiene‐based molecules. However, the dinuclear complex 6 afforded ethynylferrocene under the measurement conditions. 相似文献
15.
Jing Wang Xi Chen Xiu Wang Wei-Qiang Zhang Hua-Ming Sun Guo-Fang Zhang Ya Wu Zi-Wei Gao 《Transition Metal Chemistry》2016,41(7):731-738
Tunable organometallic Lewis acid catalysts were developed by combining salicylic acid (H2-Sal) with benzoic acid (H-Ben), 4-fluorobenzoic acid (H-BenF) and 3-thiophenic acid (H-Th), as coligands for mixed bis-carboxylate titanocene complexes. Three air-stable complexes [Cp2Ti(η1-HSal)(η1-Ben)] (1), [Cp2Ti(η1-HSal)(η1-BenF)] (2) and [Cp2Ti[η1-HSal][(η1-Th)] (3) were prepared in high yields by the reaction of salicylato titanocene chelate with carboxylate ligands. The mixed bis-carboxylate titanocene complexes were fully characterized by physicochemical and spectroscopic methods. Single-crystal X-ray diffraction studies revealed Ti–O(H-Sal) bond distances in 1, 2 and 3 of 1.972(3), 1.9245(18) and 1.912(5) Å, respectively, while the bond distances involving the coligands of 1, 2 and 3 are 1.908(3) Å (Ti–OBen), 1.9296(19) Å (Ti–OBenF) and 1.945(5) Å (Ti–OTh), respectively. These bis-carboxylate titanocene complexes showed satisfactory activities and selectivities in Mannich and cross-aldol reactions. Notably, complex 3 bearing the labile thiophene carboxylate ligand gave high yields with a diastereomer ratio (d.r.) as high as 1:99 for the direct Mannich reactions of benzaldehyde, cyclohexanone and aniline. In cross-aldol reaction of benzaldehyde and cyclohexanone, 1 and 2 successfully catalyzed the formation of double-aldol products in up to 99 % yield. 相似文献
16.
Ziwei Gao Caiyun Zhang Mingyuan Dong Lingxiang Gao Guofang Zhang Zhaotie Liu Gaofeng Wang Denghui Wu 《应用有机金属化学》2006,20(2):117-124
Two 4‐coordinated titanocene complexes, [(η5‐C5H5)2Ti(O,O′)(5‐NO2‐OCC6H3)] (I) and [(η5‐C5H5)2Ti(2‐OH‐5‐NO2‐O2CC6H3)2] (II), have been synthesized by reaction of Cp2TiCl2 and 5‐nitrosalicylic acid in aqueous media. Single‐crystal X‐ray analyses of I and II display the mononuclear forms of TiIV, and geometries at titanium atoms are distorted tetrahedrons, while the coordination environment at TiIV in complex I is different from that in complex II. Crystallographic characterization revealed that each of the complexes exhibits a three‐dimensional framework constructed through weak interactions, which are H‐bonding, π–π stacking and C–H·π interactions, but they differ greatly when forming the three‐dimensional network structure in both complexes. The results show that the dramatic change of conditions has great effect on the molecular structure of 5‐nitrosalicylate titanocene, thereby significantly influencing the weak interactions and the specific framework structure. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
17.
The reaction of anilides with the titanium carbene complexes generated by the desulfurization of thioacetals with the titanocene(II) species Cp2Ti[P(OEt)3]2 produced the corresponding enamines. Unusual formation of pyrrolidines was observed when N-[3,3-bis(phenylthio)propyl]anilides were treated with the titanocene(II) reagent. 相似文献
18.
By the reaction of KCN with Cp2TiCl2 (Cp = η5-C5H5) in boiling methanol, bis(cyclopentadienyl)-methoxytitanium(IV) cyanide, Cp2Ti(OCH3)CN, is formed which in air is converted into the dinuclear oxygen-bridged derivative (Cp2TiCN)2O. By the same procedure, the bis(methylcyclopentadienyl) analogue [MeCp2TiCN]2O has been obtained. An X-ray diffraction study of (Cp2TiCN)2O has shown that the CN group acts as a unidentate ligand with a Ti? C bond length of 2.158 Å and a Ti? C? N bond angle of 177.7°, very close to linearity. The Ti? O bond distance, 1.836 Å, and the bond angle at the bridging O atom, 174.1°, are normal. The ligands are arranged in a nearly tetrahedral way around the Ti atoms. The structural results are compared to those for similar dinuclear titanium complexes. 相似文献
19.
Samir Kumar Mandal 《Tetrahedron letters》2007,48(23):4131-4134
A radically promoted synthesis of 3,4-dihydroisocoumarins has been achieved in moderate to good yields using titanocene(III) chloride (Cp2TiCl) as the radical initiator. The total synthesis of (±)-hydrangenol has been completed using this radical technology. Cp2TiCl was prepared in situ from commercially available titanocene dichloride (Cp2TiCl2) and Zn-dust in THF under argon. 相似文献
20.
Bis(trifluoromethyl)mercury Hg(CF3)2 and mercurybis(trifluoroacetate) Hg(OCOCF3)2 react with some non-metals directly to form the corresponding trifluoromethyl compounds in high yields: Hg (OCOCF3)2 + 2 I2 → 2 CF3I + HgI2 + 2CO2 Hg (CF3)2 + 2 Br2 → 2 CF3Br + HGBr2 Hg (OCOCF3)2 + 4 S → CF3SSCF3 + CF3SCF3 + HgS + 2 CO2Both mercury-compounds also react in a similar way with some binary non-metal compounds, e.g. ICl and SCl2, respectively.These reactions as well as the reactions of Hg(SCF3)2 with ICl and ICl3, the n.m.r. spectra and some properties will be reported. 相似文献