Search results for "Adduct"
showing 10 items of 320 documents
The Crystal Structure of the THF Adduct of Monolithioferrocene
2015
Single crystals of [Fe(η5-C5H4)(η5-C5H5)]2Li2(thf)4 (1) were obtained from a tetrahydrofuran solution containing monolithioferrocene. The title compound crystallizes in the monoclinic space group P21 with a = 9.6589(5) A, b = 17.4285(9) A, c = 30.3116(15) A, β = 91.911(2)° and V = 5099.8(5) A3 with three independent molecules of 1. All individual molecules feature a non- symmetric almost planar Li2C2 four-membered ring with two shorter (2.118–2.215 A) and two longer Li–C distances (2.257–2.309 A). The lithium cations are each coordinated by two carbanionic atoms of two ferrocenyl substituents and two tetrahydrofuran molecules in a distorted tetrahedral fashion. All ferrocenyl moieties displ…
Mössbauer spectroscopy of mono-organotin(IV) derivatives
1974
Abstract The Mossbauer parameters isomer shift, δ, and quadrupole splitting, ΔE, of mono-organotin compounds insofar investigated have been collected and tabulated. It is demonstrated that isomer shifts consistently depend on ligand electronegativities and coordination numbers, from which it is deduced that RSn IV behave much more as Sn IV rather than R 2 Sn IV and R 3 Sn IV derivatives. The changes of δ for RSn IV are then interpreted by hypotheses analogous to those advanced for Sn IV and its adducts and complexes. It is also inferred that in RSn IV compounds there is a consistent s-character in all tin-ligand atom bonds.
Novel Alkylanthracenes Synthesis, Reductive Alkylation, and Reductive Polymerization
1988
A series of novel substituted anthracenes has been prepared which carry two or four n-alkyl groups at C-2 and C-3 (C-6 and C-7). The route taken includes the synthesis of novel 2,3-dialkylbutadienes, their Diels-Alder reaction with 1,4-benzo- or 1,4-naphthoquinone, the dehydrogenation of the adducts, and the reduction of the anthraquinones. The substituted anthracenes are submitted to reduction and reductive alkylation in ethereal solvents and in liquid ammonia to yield 9,10-dialkyl-substituted 9,10-dihydroanthracenes. A modification of the reductive alkylation, i.e. the introduction of 1,n-dihaloalkanes as electrophiles, provides polymeric chains, in which dihydroanthracene moieties are li…
Organometallic early lanthanide clusters: syntheses and X-ray structures of new monocyclopentadienyl complexes.
2004
The reaction of Ln(BH(4))(3)(THF)(3) or LnCl(3)(THF)(3) with 1 equiv of KCp*' ligand (Cp' = C(5)Me(4)n-Pr) afforded the new monocyclopentadienyl complexes Cp*'LnX(2)(THF)(n) (X = BH(4), Ln = Sm, n = 1, 1a, Ln = Nd, n = 2, 1b; X = Cl, Ln = Sm, n = 1, 3a) and [Cp*'LnX(2)](n') (X = BH(4), n' = 6, Ln = Sm, 2a, Ln = Nd, 2b; X = Cl, Ln = Nd, 4b). All these compounds were characterized by elemental analysis and (1)H NMR. Crystals of mixed borohydrido/chloro-bridged [Cp*'(6)Ln(6)(BH(4))(12-x))Cl(x)(THF)(n')] (x = 10, n' = 4, Ln = Sm, 2a', Ln = Nd, 2b'; x = 5, n = 2, Ln = Sm, 2a' ') were also isolated. Compounds 2a, 2b, 2a', 2b', and 2a'' were structurally characterized; they all exhibit a hexameric…
Bonding Trends in Lewis Acid Adducts of S 4 N 4 – X‐ray Structure of TeCl 4 ·S 4 N 4
2006
Tetrasulfur tetranitride and tellurium tetrachloride react in dichloromethane to form a 1:1 adduct TeCl4·S4N4 (1). The crystal structure of 1 shows that TeCl4 is bonded to the S4N4 ring through a Te–N linkage. As a consequence, the transannular S···S bonds in S4N4 are broken and the molecule assumes an open, monocyclic conformation. The Te–N bond of 2.16(1) A is slightly longer than the single bond. The S–N bonds span a range of 1.55(1)–1.67(1) A. The adduct 1 was also characterized by mass spectrometry and Raman spectroscopy. The bonding and spectroscopic properties of 1 are compared by DFT calculations at the B3PW91/(RLC ECP) level of theory with those of BF3·S4N4 (2), SO3·S4N4 (3), AsF5·…
Isomerisierung der Dihydropentalene und Umsetzung mit Tetracyanethylen
1987
Zwischen den sechs isomeren Dihydropentalenen 1–6 existieren eine Reihe von H-Verschiebungen (Schema 1), die in Gasphasenpyrolysen untersucht werden. Der thermodynamisch kontrollierte irreversible Ausgang aus den Gleichgewichten von 1–6 fuhrt uber 1-Vinylfulven (14) zu Styrol (15). Praparativ nutzlich ist besonders die katalytische Isomerisierung zwischen 1,5-DHP (4) und 1,2-DHP (1) bei Raumtemperatur. Die Umsetzung der Dihydropentalene mit Tetracyanethylen liefert bei 1 das [2+2]-Addukt 24, bei 3 und 5 die [4+2]-Addukte 25 bzw. 26 und bei 4 das doppelte [4+2]-Addukt 22.2 und 6 lassen sich unter Blitzpyrolyse-Bedingungen mit TCNE nicht abfangen. Isomerization of Dihydropentalenes and Reacti…
Syntheses and reactivity of aminobis(diorganylamino)phosphanes
1996
Aminobis(diorganylamino)phosphanes (R2N)2PNH2 (R = iPr, c-Hex, Ph) (2a–c), were obtained by treatment of the corresponding chlorobis(diorganylamino)phosphanes 1a–c with lithium amide in liquid ammonia. The transition metal phosphane complex (R2N)2(H2N)PNi(CO)3 (3) was prepared by reaction of 2a with tetracarbonylnickel. N-Complexation of 2a with trimethylalane affords the iminophosphorane-alane adduct (R2N)2HP=N(H)AlMe3 (4) by 1,2-H shift from the nitrogen to the phosphorus atom. The corresponding reaction with aluminium trichloride leads to the formation of the salt [(R2N)2HP=N(H)]2AlC12+[AlC14]− (5), in which two iminophosphorane moieties are linked by an AlCl2 bridge. Lithiation of 2a an…
New Insights into the Stoichiometric and Catalytic Reactivity of Unsaturated Pd 3 (dppm) 3 CO n + Clusters ( n = 0, 1) Towards Halocarbons – First Ev…
2005
The title clusters, Pd 3 (dppm) 3 (CO) + and Pd 3 (dppm) 3 (CO) 0 can be electrochemically generated from the 1- and 2-electron reductions, respectively, of the Pd 3 (dppm) 3 (CO) 2 + cluster [dppm = bis(diphenylphosphanyl)methane; Pd 3 2 + ]. Pd 3 + reacts in a stoichiometric ratio with methyl iodide, MeI, and benzyl bromide, BzBr, in THF to provide the corresponding Pd 3 (X) + adducts (X = I, Br respectively) as inorganic products. Other products are Bz 2 and PhMe for BzBr but, for MeI, no organic product was observed (since they are too volatile). In the presence of the same substrates, Pd 3 0 also reacts in a stoichiometric ratio to form the same organics and the Pd 3 -(X) + adducts (X …
Formation and Reactivity of a Tantalocene Trihydride Containing an Aminoethyl‐Functionalised Ligand
2003
The complex [Cp*{C5H4(CH2CH2NMe2)}TaCl2] (1) was synthesised by reaction of the lithium salt LiC5H4(CH2CH2NMe2) with the tantalum compound [Cp*TaCl3(PMe3)]. Reduction of 1 with NaAl(H)2(OCH2CH2OMe)2 leads to the trihydride derivative [Cp*{C5H4(CH2CH2NMe2)}TaH3] (2). The oxidation of 2 in THF with ferrocenium ion leads to a cationic dihydride intermediate [Cp*{C5H4(CH2CH2NMe2)}TaH2]PF6 (3) with an intramolecular stabilization by the aminoethyl side-chain of the cyclopentadienyl ligand. The hemilabile character of the functionalised cyclopentadienyl ligand was checked by treating 3 with electron-donating ligands (e.g. phosphanes, sulfides, anions); in all cases, no displacement of the amino g…
Adduct formed by chromium trioxide and zwitterionic quinolinic acid
2010
Abstract Chromium trioxide forms an adduct with zwitterionic quinolinic acid. The structure of the product was found to be (quinolinium-3-carboxylato-O)trioxidochromium(VI), determined by single-crystal X-ray diffraction methods. To evaluate the bonding properties of the compound, its structure was optimized at the B3LYP/6-311G* level of theory. The electronic characteristics were investigated by topological methods applied to the total charge density in various model compounds including the title compound, title compound with a HF molecule presenting a hydrogen bonding and anionic moiety. Calculated aromaticity indices indicate that the quinolinic rings tend to conserve their degree of aro…