Thermally induced elimination of bis(trimethylsilyl)acetylene from its titanocene complex [{η5-C5Me4(SiMe3)}2Ti(η2-Me3SiC⋮CSiMe3)] (1) afforded the stable [{η5-C5Me4(SiMe3)}2TiII] (2) in high yield under mild conditions. Compound 2 exhibits paramagnetic line broadening 1H NMR signals, although it is silent EPR spectra down to −196 °C. The solid-state structure determination revealed an exactly parallel arrangement cyclopentadienyl rings due crystallographically imposed symmetry. Complex...

Thermolysis of bis(tetramethylcyclopentadienyl)-stabilized titanium(III) compounds (C5HMe4)2TiR (R = Me (2), Ph (3)) yields, in marked contrast with the bis(pentamethylcyclopentadienyl) analog, dimeric product [(C5HMe4)(μ-η1:η5-C5Me4)Ti]2 (4), a bridging metalated tetramethylcyclopentadienyl ligand. The hydride (C5HMe4)2TiH (5), synthesized by hydrogenolysis 2 or 3, reacts N2 to form dinuclear Ti(II) dinitrogen compound [(C5HMe4)2Ti]2N2 (8). Under dynamic vacuum, complex 8 loses ligand give...

ABSTRACT The Oligo‐Miocene Most Basin is the largest preserved sedimentary basin within Eger Graben, easternmost part of European Cenozoic Rift System (ECRIS). interpreted as a an incipient rift system that underwent two distinct phases extension. first phase, characterised by NNE–SSW‐ to N–S‐oriented horizontal extension between end Eocene and early Miocene, was oblique axis caused evolution fault en‐échelon‐arranged E–W (ENE–WSW) faults. These faults defined number small, shallow initial...

Geology and palaeontology of the Roudníky area, situated between Most Basin České středohoří Mountains in North Bohemia, Czech Republic, is treated detail.The volcano-sedimentary structure underlying basin with included fossiliferous layers newly interpreted as a maar-diatreme.The radiometric age basalts was determined to 35.4 ± 0.9 Ma 37.1 -late Eocene, Priabonian.The fish fauna consists amiids characteristic other adjacent late Eocene sites while co-occurring macroflora includes many...

Abstract The Early Miocene Bílina Palaeodelta consists of fluvio‐deltaic and lacustrine clastics deposited along the south‐eastern margin extensional Most Basin, part Eger Graben in north Bohemia (Czech Republic). succession shows evidence repeated advances an axial deltaic system across a thick accumulation organic material clay hangingwall active fault. Exposures up to ca 4·5 km long open‐cast mine help bridge gap between seismic scale typical outcrop observation thus allow relationships...

Abstract Polymerization of isoprene with Lewis acids in n ‐heptane is a process leading to quasiequilibrium which characterized by very low conversions. rates aromatic solvents are much higher due extensive chain transfer solvent regeneration the original active centers. The rate monomer disappearance benzene or toluene when aluminum bromide catalyst second order respect concentration. reaction depends on conditions; at constant concentration it approximately one. halogenated use syringe...

The (C5H5-nMen)2Zr[η2-C2(SiMe3)2] (n = 2−5; 1,3-dimethyl, 1,2,3-trimethyl) (2C−F) complexes were prepared by the reduction of corresponding zirconocene dichlorides with magnesium in THF presence bis(trimethylsilyl)acetylene (BTMSA). All them are stable absence THF. Crystal structures (C5HMe4)2Zr[η2-C2(SiMe3)2] (2E) and (C5Me5)2Zr[η2-C2(SiMe3)2] (2F) analogous titanium isomorphous. red shift ν(C⋮C) vibration downfield 13C δ(C⋮C) indicate that BTMSA 2C−F is more strongly coordinated than...

The singly tucked-in permethyltitanocene 1 reacts with an excess of internal alkynes to give the 1:1 adducts 3a−c,f−i, arising from insertion alkyne triple bond into titanium−methylene bond. Only simplest species, 2-butyne, inserted two molecules known compound 2; however, at a stoichiometric ratio adduct 3j was also smoothly formed. 1,4-Disubstituted conjugated diynes CMe3 or SiMe3 substituents reacted in same way by only one 3d,e, respectively. dimethylsilylene-bridged dialkynes...

Reduction of [ZrCl2{η5-C5Me4(SiMe3)}2] (1) with excess magnesium in tetrahydrofuran affords a mixture the monomeric zirconocene hydride [ZrH{η1:η5-C5Me4(SiMe2CH2)}{η5-C5Me4(SiMe3)}] (2) and dimeric, tetranuclear Zr(III)− Zr(IV)−magnesium complexes 3 4, respectively. In presence bis(trimethylsilyl)ethyne (btmse), similar reduction yields η2-alkyne complex [Zr{η5-C5Me4(SiMe3)}2(η2-btmse)] (5) as major product compounds 2−4 minor impurities. Upon thermolysis under vacuum, 5 undergoes 2-fold...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTitanium-magnesium-assisted scission of 1,4-bis(trimethylsilyl)-1,3-butadiyne: synthesis and structure a titanium(III) tweezer complex, [(.eta.5-C5HMe4)2Ti(.eta.1-C.tplbond.CSiMe3)2][Mg(THF)Cl]Sergei I. Troyanov, Vojtech Varga, Karel MachCite this: Organometallics 1993, 12, 7, 2820–2824Publication Date (Print):July 1, 1993Publication History Published online1 May 2002Published inissue 1 July...

Matrix isolation studies on CH3COOH, CH3COOD and CD3COOD, using e.s.r. to identify trapped radicals, suggest a mechanism for the γ-radiolysis of acetic acid at low temperatures. It is suggested that primary anion, CH3ĊOOH–, which only species observed –196°C, dissociates into CH3CO–2 H, latter reacting further give CH3CO H2O. The molecular cation CH3ĊOOH+ not observed, but CH3 radicals in acid/water matrices are thought be decomposition products, together with CO2. proposed radiolysis solid...

Six sediment cores from two of four depocentres in the Most Basin, mostly consisting macrofossil barren fluviodeltaic and lacustrine sediments Holešice Libkovice members Formation (lower Miocene, Burdigalian) were subjected to chemostratigraphic correlation, based on CEC EDXRF proxy element analyses.CEC-step, prominent K/Al minima crandallite-bearing horizons monotonous mudstones Member provide several local isochronous or nearly key horizons, which we propose for a basin-scale correlation...

Ethene complexes of titanocenes [Ti(II)(η2-C2H4)(Cp′)2] for Cp′ = η5-C5Me5 (1), η5-C5Me4t-Bu (2), η5-C5Me4SiMe3 (3), and η5-C5HMe4 (4) were prepared by reduction corresponding titanocene dichlorides with magnesium in THF the presence ethene. Thermolysis 1–3 toluene solution at a maximum 100 °C resulted elimination ethane, affording cleanly doubly tucked-in compounds 5–7, respectively. Experiments 2 3 NMR tubes proved that symmetrical isomers 6a 7a formed first, these thermally isomerized to...

Abstract This study reports on a ~ 150 m thick macrofossil-barren sequence of siliciclastic sediments from Burdigalian age (Early Miocene) freshwater lake. The lake was located within an incipient rift system the Most Basin in Ohře (Eger) Graben, which part European Cenozoic Rift System, and had original area ≈ 1000 km 2 . Sediments HK591 core that cover entire thickness deposits some adjacent stratigraphic units were analysed by X-ray fluorescence spectroscopy (a proxy for element...

The reduction of symmetric, fully-substituted titanocene dichlorides bearing two pendant ω-alkenyl groups, [TiCl2(η5-C5Me4R)2], RCH(Me)CH=CH2 (1 a), (CH2)2CH=CH2 b) and (CH2)3CH=CH2 c), by magnesium in tetrahydrofuran affords bis(cyclopentadienyl)titanacyclopentanes [TiIV{η1:η1:tlsb&=ndash;3%>η5:η5-C5Me4CH(Me)CH(Ti)CH2CH(CH2(Ti))CH(Me)C5Me4}] (2 [TiIV{η1:η1:η5:η5-C5Me4(CH2)2CH(Ti)(CH2)2CH(Ti)(CH2)2C5Me4}] [TiIV{η1:η1:η5:η5-C5Me4(CH2)2CH(Ti)CH(Me)CH(Me)CH(Ti)(CH2)2C5Me4}] respectively, as...