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The bis(stibido) complex CpCp*Hf(SbMes2)2 (2) was prepared and structurally characterized. Complex 2 reacts with 2 equiv of xylylisocyanide to give the bis-insertion product CpCp*Hf[C(SbMes2)=N(2,6-MeC6H3)]2 (4). The reaction of 2 with oxidants (I2 and O2) or donors (carbon monoxide and diphenylacetylene) or thermolysis promotes the reductive elimination of Sb2Mes4. 相似文献
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Complex OsH(6)(P(i)Pr(3))(2) (1) reacts with 1-methylthymine and 1-methyluracil to give OsH(3)(P(i)Pr(3))(2)(nucleobase') (2, 3) containing the deprotonated nucleobases (nucleobase') κ(2)-N,O coordinated by the nitrogen atom at position 3 and the oxygen bonded to the carbon atom of the ring at position 4. Similarly, the reactions of 1 with thymidine, 5-methyluridine, deoxyuridine, and uridine lead to OsH(3)(P(i)Pr(3))(2)(nucleoside') (4-7) with the deprotonated nucleoside (nucleoside') κ(2)-N,O coordinated by the nitrogen atom at position 3 and the oxygen bonded to the carbon atom at position 4 of the nucleobases. Treatment of complexes 5 and 7, containing nucleosides derived from ribose, with OsH(2)Cl(2)(P(i)Pr(3))(2) (8) in the presence of Et(3)N affords dinuclear species OsH(3)(P(i)Pr(3))(2)(nucleobase')-(ribose)(P(i)Pr(3))(2)H(2)Os (9, 10) formed by two different metal fragments. Complex 1 also promotes the cleavage of the N-C bond of 2-7 to give the dinuclear species {OsH(3)(P(i)Pr(3))(2)}(2)(nucleobase') (11, 12) with the nucleobase skeleton (nucleobase') κ(2)-N,O coordinated to both metal fragments. These compounds can be also prepared by reaction of 1 with 0.5 equiv of thymine and uracil. The use of 1:1 hexahydride:nucleobase molar ratios gives rise to the preferred formation of the mononuclear complexes OsH(3)(P(i)Pr(3))(2)(nucleobase') (13, 14; nucleobase' = monodeprotonated thymine or uracil). The X-ray structures of complexes 6, 11, and 14 are also reported. 相似文献
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Morello L Love JB Patrick BO Fryzuk MD 《Journal of the American Chemical Society》2004,126(31):9480-9481
The dinuclear dinitrogen complex ([P2N2]Zr)2(mu-eta2:eta2-N2) reacts with terminal aryl alkynes to generate a new species in which the dinitrogen unit has been functionalized. The products formed have the general formula ([P2N2]Zr)2(mu-eta2:eta2-N2CCAr)(mu-CCAr) and display a styryl-hydrazido unit bridging the two Zr centers along with a bridging arylalkynide. The crystal structures of three of these products are reported. A mechanism is proposed for this process that involves cycloaddition of the alkyne to the side-on dinitrogen unit followed by protonation of the Zr-C bond by a second equivalent of terminal alkyne. A fluxional process is operative in solution that equilibrates the phosphorus nuclei at high temperature; in the slow exchange limit, the two [P2N2]Zr ends of complex are inequivalent as evidenced by four resonances in the 31P NMR spectrum for the inequivalent phosphorus donors. This C-N bond-forming reaction is unique in that an activated dinitrogen fragment undergoes a reaction with an alkyne. 相似文献
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The factors affecting the formation of zirconium and hafnium complexes of xylenol orange (XO) in perchloric acid have been examined. The optimum acid concentration for both systems is in the range 0.2–0.5 M HClO4. When excess of metal is present, an initial complex with (XO) : metal ratio of 1 :1 is formed; this complex then undergoes an acid-dependent reaction, taking approximately 2 h to reach completion. Rate constants for this reaction have been determined. When excess of xylenol orange is present (i.e.(XO) : metal ? 2) a 2 :1 complex is formed which does not undergo further reaction. Extinction coefficients are given for the various complexes. 相似文献
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Fryzuk MD Kozak CM Bowdridge MR Patrick BO Rettig SJ 《Journal of the American Chemical Society》2002,124(28):8389-8397
The reduction of [P(2)N(2)]NbCl (where [P(2)N(2)] = PhP(CH(2)SiMe(2)NSiMe(2)CH(2))(2)PPh) with KC(8) under a dinitrogen atmosphere generates the paramagnetic dinuclear dinitrogen complex ([P(2)N(2)]Nb)(2)(mu-N(2)) (2). Complex 2 has been characterized crystallographically and by EPR spectroscopy. Variable-temperature magnetic susceptibility measurements indicate that 2 displays antiferromagnetic coupling between two Nb(IV) (d(1)) centers. A density functional theory calculation on the model complex [(PH(3))(2)(NH(2))(2)Nb](2)(mu-N(2)) was performed. Thermolysis of ([P(2)N(2)]Nb)(2)(mu-N(2)) in toluene generates the paramagnetic bridging nitride species where one N atom of the dinitrogen ligand inserts into the macrocycle backbone to form [P(2)N(2)]Nb(mu-N)Nb[PN(3)] (3) (where [PN(3)] = PhPMe(CHSiMe(2)NSiMe(2)CH(2)P(Ph)CH(2)SiMe(2)NSiMe(2)N)). Complex 3 has been characterized in the solid state as well as by variable-temperature magnetic susceptibility measurements. The reaction of ([P(2)N(2)]Nb)(2)(mu-N(2)) with phenylacetylene displaces the dinitrogen fragment to generate a paramagnetic eta(2)-alkyne complex, [P(2)N(2)]Nb(eta(2)-HCCPh) (4). 相似文献
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Kikuchi S Sekine K Ishida T Yamada T 《Angewandte Chemie (International ed. in English)》2012,51(28):6989-6992
A catalytic amount of silver benzoate with 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (MTBD) was an effective catalytic system for the reaction of carbon dioxide with various ketones containing an alkyne group at an appropriate position. These reactions afforded the corresponding γ-lactone derivatives in good to high yields under mild conditions. 相似文献
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Reduction of [P 2N 2]ZrCl 2 (where P 2N 2 = PhP(CH 2SiMe 2NSiMe 2CH 2) 2PPh) by KC 8 under N 2 generates the dinuclear dinitrogen complex ([P 2N 2]Zr) 2(mu-eta (2):eta (2)-N 2) and impurities in varying yields depending on the solvent and temperature. The toluene complex [P 2N 2]Zr(eta (6)-C 7H 8) along with a dinuclear species with bridging PC 6H 5 groups is observable. Also observable in the crude reaction mixtures is the mu-oxodiazenido derivative, ([P 2N 2]Zr) 2(mu-eta (2):eta (2)-N 2H 2)(mu-O), due to reaction with trace H 2O. This paper reports the full details of the preparation of ([P 2N 2]Zr) 2(mu-eta (2):eta (2)-N 2) including an improved method that involves reduction at low temperatures in a tetrahydrofuran solvent. Also reported is a reproducible synthesis of the oxodiazenido complex along with the X-ray structures of the dinitrogen complex and the oxodiazenido derivative. 相似文献
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Esteruelas MA Fernandez-Alvarez FJ Olivan M Oñate E 《Journal of the American Chemical Society》2006,128(14):4596-4597
Complex OsH2Cl2(PiPr3)2 promotes the C-H activation of 2-vinylpyridine and subsequently couples the activated substrate with a second 2-vinylpyridine and two acetylene molecules. In the absence of 2-vinylpyridine, the activated substrate is coupled with an acetylene unit to afford a 2-butadienylpyridine derivative. 相似文献
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Fischer R Zirngast M Flock M Baumgartner J Marschner C 《Journal of the American Chemical Society》2005,127(1):70-71
Reaction of the magnesium transmetalation product of a 1,2-dipotassiodisilane with hafnocene dichloride gives a disilene hafnocene complex. X-ray crystallography of the respective trimethylphosphane adduct provides structural proof for this assignment. 相似文献
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L. I. Strunkina M. Kh. Minacheva P. V. Petrovskii Z. S. Klemenkova B. V. Lokshin V. V. Burlakov V. B. Shur 《Russian Chemical Bulletin》1997,46(4):820-823
The first acetylene complex of hafnium, Cp2Hf[Me3SiC=CHf(H)Cp2], was synthesized by the reaction of hafnocene dihydride Cp2HfH2 with bis(trimethylsilyl)acetylene in benzene. The reaction is accompanied by elimination of the Me3Si group from the molecule of the initial acetylene, as a result of which the acetylenide derivative of hafnium Cp2Hf(C=CSiMe3)(H) acts as an acetylene ligand in the complex. Under analogous conditions, the reaction of zirconocene dihydride Cp2ZrH2 with bis(trimethylsilyl)acetylene affords an analogous acetylene complex of zirconium Cp2Zr(M3SiC=CZr(H)Cp2]. Reactions of Cp2HfH2 with tolane and 3-hexyne proceed differently than the reaction with bis(trimethylsilyl)acetylene. Here the corresponding
hafnacyclopentadiene metallacycles are the final products.
For preliminary communication, see Ref. 3.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 853–856, April, 1997. 相似文献
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Catalytic C-C bond cleavage of acetonitrile and C-Si bond formation have been attained in the photoreaction of MeCN with Et3SiH in the presence of an iron complex, Cp(CO)2FeMe. This catalytic system can be applied for arylnitrile C-C bond cleavage. 相似文献
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Hirotsu M Fontaine PP Zavalij PY Sita LR 《Journal of the American Chemical Society》2007,129(42):12690-12692
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Summary 3-Hydroxyflavone, morin and quercetin are suitable for the fluorescent detection of hafnium and zirconium under proper acidity and reagent concentration conditions. 3-Hydroxyflavone is the most sensitive reagent for both metals. Substantially acid solutions are preferred for the reactions of hafnium and zirconium to increase selectivity despite decreasing reaction sensitivity. The hydroxyflavone hafnium chelates are more stable to acid than the zirconium chelates especially with morin and quercetin. The very low background fluorescence of quercetin permits the detection of hafnium in strong perchloric acid where the fluorescence of the other two reagents hinders detection.
Zusammenfassung 3-Hydroxyflavon(I), Morin(II) und Quercetin(III) eignen sich bei bestimmter Acidität und Reagenskonzentration zum Fluoreszenznachweis von Hafnium und Zirkonium. I ist das empfindlichste Reagens für beide Metalle. Deutlich saure Lösungen steigern die Selektivität der Reaktionen, setzen aber die Empfindlichkeit herab. Das Hafnium-I-Chelat ist gegenüber Säure stabiler als die Zirkoniumchelate, besonders von II und III. Die sehr geringe Untergrundfluoreszenz von III ermöglicht den Hafniumnachweis in starker Perchlorsäure, worin die Fluoreszenz der beiden anderen Reagenzien den Nachweis verhindert.相似文献
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《Journal of organometallic chemistry》1986,302(1):C7-C9
The one-electron reduction of zirconocene and hafnocene dichlorides Cp2MCl2 (M = Zr or Hf) yields the corresponding anion Cp2MCl2−. There is no cleavage of an MCl bond, in contrast to the result in the case of the analogous titanocene and vanadocene dichlorides. 相似文献