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1.
Two [MoOCl3(THF)2] molecules are used for detachment of two Cl atoms from [MgCl2(THF)2]. In such reaction a green crystalline salt [Mg(THF)6][MoOCl4THF]2 IV is formed. Compound IV reacts further with 3 equivalents of bis(tetrahydrofuran)magnesium dichloride, yielding a green ionic [Mg2(m?-Cl)3(THF)6][MoOCl4THF] compound V . Compound IV and V vary only in a structure of cation what indicated that the tri-m?-chlorohexakis(tetrahydrofuran)dimagnesium(II) cation in V is really formed in reaction between [Mg(THF)6]2+ cation and [MgCl2(THF)2]. The crystal structure of compounds IV and V has been solved by X-ray diffraction method. The [Mg(THF)6]2+ cation forms the tetragonally distorted octahedron with the magnesium atom in the symmetry centre. In homobimetallic di-octahedral [Mg2(m?-Cl)3(THF)6]+ cation the magnesium atoms are surrounded by three bridging chlorine atoms and three THF molecules. The structures of [MoOCl4THF]? in IV and V are similar. In those anions the molybdenum atom is hexacoordinated with four chlorine atoms in equatorial plane. 相似文献
2.
The crystalline compound [K([18]crown-6){C6H4(SiMe3)2-1,4}] (1) was prepared by the low-temperature reduction of the para-disilylated benzene with K/[18]crown-6 in toluene followed by recrystallisation from the same solvent. Reduction of 1,2,4,5-tetrasilylated benzene with 2(K/[18]crown-6) in toluene produced a hydrocarbon-insoluble powder identified as the dianionic derivative [K([18]crown-6)]2[C6H2(SiMe3)4-1,2,4,5)] (2), which upon crystallisation from THF/Et2O yielded [K([18]crown-6)(THF)2][C6H2(SiMe3)4-1,2,4,5] (3). An X-ray diffraction study revealed that 1 comprised a contact ion pair with the crown-encapsulated K cation η5-connected to the planar ring of the substituted benzene radical anion, while 3 contained a well separated cation and anion. 相似文献
3.
《Tetrahedron》1986,42(22):6111-6121
Reactions are reported between RMgCl and thianthrene cation radical perchlorate (Th.+ClO-4) suspended in ether and tetrahydrofuran (THF). In ether solution reactions R = Bu, s-Bu, t-Bu, 5-hexenyl, and cyclopentylmethyl. Major products were the alkane, the alkene R(-H) in some cases, and, in the cases of R = Bu, 5-hexenyl, and cyclopentylmethyl, the 5-alkylthianthrenium perchlorate (ThR+ClO-4). When 5-hexenylMgCl was used a mixture of 5-(5-hexenyl)- and 5-(cyclopentylmethyl)thianthrenium per-chlorates in the ratio of approximately 2 was obtained. Since the ratio of 5-hexenyl/cyclopentylmethyl in the Grignard reagent was 10.4, it is concluded that the C6 sulfonium ions were formed by radical trapping by Th.+ after single electron transfer from Grignard to cation radical had occurred, thus allowing for cyclization of 5-hexenyl radical. Formation of ThBu+ClO-4 is attributed to the trapping of butyl radical by Th·+, while formation of RH and R(-H) is in all cases also attributed to alkyl radical reactions. Reactions in THF(R = Me, i-Pr, Bu, s-Bu, t-Bu, Ph) led almost exclusively to RH and Th. Polymerization of THF was also initiated and took place slowly giving rise to low molecular weight poly(THF). By using THF-d8, as solvent for reaction between BuMgCl and Th.+, it was possible to find Bu groups (1H-NMR) in the poly(THF-d8). Polymerization of THF is attributed, in some cases (R = Me, Bu), to alkyl-cation transfer from ThR+ to THF. In other cases initiation of polymerization by R+ and THF(-H)+ is considered. 相似文献
4.
Investigations are reported on polymerizations of 2- and 4- vinylpyridine, styrene and butadiene by a series of related alkaline earth metal initiators, Ph3CMX(THF)n (M = Ca, Ba, X = Cl, n = 2; M = Ca, X = Br, n = 4; M = Sr, X = Cl, n = 4; M = Sr, X = Br, n = 5) in tetrahydrofuran (THF) or 1,2-dimethoxyethane (DME) at various temperatures and in the absence of solvent. The polymers have been examined by GPC and aspects of their microstructures determined by 13C and/or 1H NMR spectroscopy and, for polybutadiene, i.r. spectroscopy. Poly-2-vinylpyridine produced by Ph3CMX(THF)n is rich in isotactic content; the isotacticity is higher for polymer formed in THF than DME solution, falls with change of initiator in the order M = Ca > Sr > Ba and, in DME, is greater when X = Br. The tacticities of poly-4-vinylpyridine and polystyrene are similar to those obtained from related organometallic initiators. The 1,4-content of polybutadiene decreases with initiator Ph3CMX(THF)n in the order M = Ba > Sr > Ca; the trans-1,4 structure generally predominates except when M = Ba from which cis-1,4 links are formed in comparable amounts. 相似文献
5.
The carbodiphosphorane C(PPh3)2 ( 1 ) reacts with [Mn2(CO)10] in THF to produce quantitatively the salt‐like complex (HC{PPh3}2)[Mn(CO)5] ( 2 ) as THF solvate. If the reaction is carried out in 1,2‐dimethoxyethane (DME) small amounts of [Mn(OPPh3)2{O2CC(PPh3)2}2][Mn(CO)5]2 ( 3 ) as DME solvate along with solvent free 2 as the main product were isolated. Proton abstraction from the solvent led to the formation of 2 ; the ligands OPPh3 and O2CC(PPh3)2}2 of 3 are the results of a side reaction from [Mn2(CO)10] and 1 in a Wittig type manner. From the reaction in benzene small amounts of 3 were also obtained, crystallizing as benzene solvate 3· 4C6H6. The crystal structures of 2· THF, 2 , 3· 1.75DME and 3· 4C6H6 are reported. The compounds are further characterized by IR and 31P NMR spectroscopy. 相似文献
6.
N.A. Ustynyuk B.V. Lokshin Yu.F. Oprunenko V.A. Roznyatovsky Yu.N Luzikov Yu.A. Ustynyuk 《Journal of organometallic chemistry》1980,202(3):279-289
IR and PMR spectroscopy was used to study the reversible isomerization of η6- and η5-fluorenylchromium tricarbonyl anions (I and II, respectively) in solutions. Consideration was given to the dependence of the equilibrium position and nature of the resulting particles on the type of cation (Li+, Na+, K+, Ph3PCH3+, n-Bu4N+), the solvent and the presence of solvating cation additives (dicyclohexyl-18-crown-6 (IV), DMSO). The η5-isomer exists in THF solution as an equilibrium mixture of solvent-separated and contact ion pairs (SSIP and CIP, respectively), the cation in the latter being located near the oxygen atom of one of the carbonyl groups. The existence of such an equilibrium is also shown for the salts of the C5H5(CO)3Cr? anion. The dependence of the equilibrium constants for I ? II on the above factors was determined. For the K salt in THF solution at 28°C both IR and PMR spectroscopy gave fairly coincident values of Keq equal to 7.15 and 7.35, respectively. IR spectroscopy was applied to the kinetic studies of the reversible isomerization of K salts of I and II at 0—28°C with and without crown ether IV. The process is shown to be entropy controlled. The equilibrium position is governed by the type of cation, the degree of its solvation and the temperature. The factors promoting the formation of SSIP's lead to the equilibrium being shifted towards I. 相似文献
7.
Isolation and Characterization,Including by X‐ray Crystallography,of Contact and Solvent‐Separated Ion Pairs of Silenyl Lithium Species
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Daniel Pinchuk Dr. Jomon Mathew Alexander Kaushansky Dr. Dmitry Bravo‐Zhivotovskii Prof. Dr. Yitzhak Apeloig 《Angewandte Chemie (International ed. in English)》2016,55(35):10258-10262
Reaction of bromoacylsilane 1 (pink solution) with tBu2MeSiLi (3.5 equiv) in a 4:1 hexane:THF solvent mixture at ?78 °C to room temperature yields the solvent separated ion pair (SSIP) of silenyl lithium E‐[(tBuMe2Si)(tBu2MeSi)C=Si(SiMetBu2)]? [Li?4THF]+ 2 a (green–blue solution). Removal of the solvent and addition of benzene converts 2 a into the corresponding contact ion pair (CIP) 2 b (violet–red solution) with two THF molecules bonded to the lithium atom. The 2 a ? 2 b interconversion is reversible upon THF? benzene solvent change. Both 2 a and 2 b were characterized by X‐ray crystallography, NMR and UV/Vis spectroscopy, and theoretical calculations. The degree of dissociation of the Si?Li bond has a large effect on the visible spectrum (and thus color) and on the silenylic 29Si NMR chemical shift, but a small effect on the molecular structure. This is the first report of the X‐ray molecular structure of both the SSIP and the CIP of any R2E=E′RM species (E=C, Si; E′=C, Si; M=metal). 相似文献
8.
Daniel Pinchuk Jomon Mathew Alexander Kaushansky Dmitry Bravo‐Zhivotovskii Yitzhak Apeloig 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2016,128(35):10414-10418
Reaction of bromoacylsilane 1 (pink solution) with tBu2MeSiLi (3.5 equiv) in a 4:1 hexane:THF solvent mixture at −78 °C to room temperature yields the solvent separated ion pair (SSIP) of silenyl lithium E‐[(tBuMe2Si)(tBu2MeSi)C=Si(SiMetBu2)]− [Li⋅4THF]+ 2 a (green–blue solution). Removal of the solvent and addition of benzene converts 2 a into the corresponding contact ion pair (CIP) 2 b (violet–red solution) with two THF molecules bonded to the lithium atom. The 2 a ⇌ 2 b interconversion is reversible upon THF⇌ benzene solvent change. Both 2 a and 2 b were characterized by X‐ray crystallography, NMR and UV/Vis spectroscopy, and theoretical calculations. The degree of dissociation of the Si−Li bond has a large effect on the visible spectrum (and thus color) and on the silenylic 29Si NMR chemical shift, but a small effect on the molecular structure. This is the first report of the X‐ray molecular structure of both the SSIP and the CIP of any R2E=E′RM species (E=C, Si; E′=C, Si; M=metal). 相似文献
9.
M. T. Duarte V. Gama S. Rabaa I. C. Santos 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(7):m278-m280
The title compound, [Fe(C10H15)2][Ni(C3OS4)2]·C4H8O or [Fe(Cp*)2][Ni(dmio)2]·THF, where [Fe(Cp*)2]+ is the decamethylferrocenium cation, dmio is the 2‐oxo‐1,3‐dithiole‐4,5‐dithiolate dianion and THF is tetrahydrofuran, crystallizes with two independent half‐anion units [one Ni atom is at the centre of symmetry (, , 0) and the other is at the centre of symmetry (, 0, )], one cation unit (located in a general position) and one THF solvent molecule in the asymmetric unit. The crystal structure consists of two‐dimensional layers composed of parallel mixed chains, where pairs of cations alternate with single anions. These layers are separated by sheets of anions and THF molecules. 相似文献
10.
L. A. Kushch E. B. Yagubskii S. V. Konovalikhin G. V. Shilov L. O. Atovmyan 《Russian Chemical Bulletin》1999,48(8):1513-1515
A new radical cation salt based on the dithiolate complex Pd(dddt)2 (dddt=5,6-dihydro-1,4-dithiine-2,3-dithiolate) with the tetrahedral anion [GaBr4]? was synthesized. The crystal and molecular structure was determined by XRD analysis. The crystal structure of the salt contains Pd(dddt)2 cation layers alternating with layers of [GaBr4]? anions along thec axis of the unit cell. The cation layers contain stacks of Pd(dddt)2, with a Pd...Pd distance of 3.011 Å. The electroconductivity of [Pd(dddt)2]2GaBr4, single crystals at room temperature is 0.25 Ohm?1 cm?1 and decreases with temperature decrease, the activation energy beingE a=0.66 eV. 相似文献
11.
《印度化学会志》2022,99(11):100749
Porous metal organic frameworks (MOFs) has shown large surface area and high micropore volume making it a promising electrode material for sensing devices. Adsorption and electronic sensitivity of copper-based open metal sites paddlewheel (Cu2(HCOO)4) towards polar, moderately polar, and non-polar organic solvent vapors (OSVs) were was investigated using density functional theory, employing B3LYP. The most stable adsorption structures were those with the OSVs interacting with the metal node of PW. Based on calculations, the adsorption energy of molecules is in the range of ?7.8 to ?24.8 kcal/mol, ?9.2 to ?25.7 kcal/mol, and ?6.6 to ?10.9 kcal/mol for polar, moderately polar, and non-polar OSVs, respectively. Also sensing activities of PW were studied from three points of view band gap changing, sensing factor, and work function changes. From the standpoint of conductivity changing, Cu-PW has (i) low sensitivity to acetonitrile, acetone, dimethyl formamide, dimethyl ether, benzene, and ethanol; (ii) moderate sensitivity to toluene, and (iii) strong sensitivity to THF detection so that its HOMO/LUMO gap of the PW is significantly decreased from 1.63 to 0.97 eV which may increase the electrical conductivity, sensing factor is 1.4 * 1011, and work function changing is 0.45 eV after THF adsorption. Thus, we suggest that Cu-PW may be used as a highly sensitive/selective and multi-time reusable sensor material for THF detection. 相似文献
12.
Setareh Akbari Razieh Sanavi Khoshnood Elaheh Hatami 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2017,91(13):2569-2577
Complexatio of the La3+ cation with 1,13-bis(8-quinolyl)-1,4,7,10,13-pentaoxatridecane(Kryptofix5) was studied in pure solvents acetonitrile (AN), methanol (MeOH), nitrobenzene (NB), tetrahydrofuran (THF), methyl acetate (MeOAC) and in various binary solvent mixtures of AN–MeOH, AN–NB, AN–THF, and AN–MeOAC systems at different temperatures using the conductometric method. The stoichiometry of the complex was found to be 1 : 1 (ML). In all cases, the variation of the log kf with composition of the solvent was non-linear. This behavior is probably due to a change in the structure of these binary mixed solvents as the composition of the medium is varied. The stability order of the complex in pure nonaqueous solvents at 25°C increases in the order: AN > THF > MeOAC > MeOH > NB. The values of thermodynamic data (ΔH c °,ΔS c °) formation of (Kryptofix5.La)3+ complex are definitely solvent dependent. 相似文献
13.
Wolfgang Petz Prof. Dr. Meike Fahlbusch Enrico Gromm Bernhard Neumüller Prof. Dr. 《无机化学与普通化学杂志》2008,634(4):682-687
The betain‐like SOC2(PPh3)2 ( 1a ) reacts with [Mn2(CO)10] in THF to produce the salt‐like complex [(CO)4Mn(SOC2{PPh3}2)2][Mn(CO)5] ( 2 ). 1a is bonded via the sulfur atoms which are arranged in trans position in the octahedral environment of the manganese atom. With InCl3 from CH2Cl2 solution the addition product [Cl3In(SOC2{PPh3}2)] ( 3 ) is obtained along with the salt (H2C{PPh3}2)[InCl4]2 ( 4 ), which is the result of proton abstraction from the solvent. The crystal structures of 2· 0.5THF and 4· CH2Cl2 are reported. The compounds are further characterized by IR and 31P NMR spectroscopy. 相似文献
14.
Hans Bock Andreas John Christian Nther Zdenek Havlas Eva Mihokova 《Helvetica chimica acta》1994,77(1):41-50
The one-electron transfer to large π-delocalized hydrocarbons provides an interesting possibility to crystallize solvent-separated ion-pair salts containing optimally solvated cations. Accordingly, the reduction of 9,10-diphenylanthracene in aprotic THF solution at a sodium metal mirror allows to grow dark-blue prismatic crystals of its radical anion and sixfold THF-solvated sodium cation. The structure of the radical anion is very similar to that recently published for the neutral molecule. According to AM1 hypersurface calculations based on the structural data, the phenyl twist angles obviously must be determined by lattice packing, and the negative charge is delocalized predominantly within the anthracene π system. The counter cation [Na⊕(THF)6], reported ordered for the first time, shows nearly octahedral coordination within a rather densily packed solvent shell. Due to the strong repulsions between the solvent molecules, its isodesmically calculated solvation enthalpy is smaller than that of the analogous dimethoxyethane complex [Na⊕(DME)3]. 相似文献
15.
Se-Young Oh Fumiteru Oguri Kazuo Akagi Hideki Shirakawa 《Journal of polymer science. Part A, Polymer chemistry》1993,31(3):781-787
The polymerization of 4-phenyl-1-butyne was carried out using metathesis and Ziegler-Natta catalysts. Especially, the Fe(acac)3-AlEt3 catalyst with toluene as a solvent produced an extremely high molecular weight polymer of Mw ≈ 106. Solubility of the polymers at room temperature in organic solvents such as benzene, toluene, dichloromethane, chloroform, and THF was excellent despite their high molecular weights. It has been indicated that the polymer prepared by the Fe(acac)3-AlEt3 catalyst is of cis form with a high stereoregularity. © 1993 John Wiley & Sons, Inc. 相似文献
16.
Layo van het Goor Piet Th. van Duijnen Carola Koper Leonardus W. Jenneskens Remco W. A. Havenith František Hartl 《Journal of Solid State Electrochemistry》2011,15(10):2107-2117
One-electron oxidation of the non-alternant polycyclic aromatic hydrocarbon pleiadiene and related cyclohepta[c,d]pyrene and cyclohepta[c,d]fluoranthene in THF produces corresponding radical cations detectable in the temperature range of 293–263 K only on the subsecond
time scale of cyclic voltammetry. Although the EPR-active red-coloured pleiadiene radical cation is stable according to the
literature in concentrated sulfuric acid, spectroelectrochemical measurements reported in this study provide convincing evidence
for its facile conversion into the green-coloured, formally closed shell and, hence, EPR-silent π-bound dimer dication stable
in THF at 253 K. The unexpected formation of the thermally unstable dimeric product featuring a characteristic intense low-energy
absorption band at 673 nm (1.84 eV; logε
max = 4.0) is substantiated by ab initio calculations on the parent pleiadiene molecule and the PF6− salts of the corresponding radical cation and dimer dication. The latter is stabilized with respect to the radical cation
by 14.40 kcal mol−1 (DFT B3LYP) [37.64 kcal mol−1 (CASPT2/DFT B3LYP)]. An excellent match has been obtained between the experimental and TD-DFT-calculated UV–vis spectra of
the PF6− salt of the pleiadiene dimer dication, considering solvent (THF) effects. 相似文献
17.
Thomas Thoma V.G. Pleshakov N.S. Prostakov Yu.A. Ustynyuk A.N. Nesmeyanov N.A. Ustynyuk 《Journal of organometallic chemistry》1980,192(3):359-365
Reactions of 2- and 4-azafluorenes (I, II) and their methyl derivatives, 3-methyl-2-azafluorene (III) and 7-methyl-4-azafluorene (IV) with chromium hexacarbonyl in a diglyme/heptane mixture at 140°C have been studied. A N-donor complex, C12H9NCr(CO)5 is formed in the reaction of I with Cr(CO)6. Compounds II–IV react to give arenechromiumtricarbonyl derivatives with benzene rather than pyridine ring bound to the metal. [η6-(4b,5,6,7,8,9b)-4-Azafluorene]chromiumtricarbonyl (VIII) gives the corresponding hydrochloride under the action of HCl. Methyl iodide decomposes VIII to produce 4-azafluorene iodomethylate. Deprotonation of VIII with BuLi in ether at ?20°C followed by dilution with hexane leads to precipitation of the corresponding Li salt (Xb), having η6-structure. Methylation of Xb with methyl iodide proceeds stereospecifically to yield the exo-methyl derivative XII. Treatment of VIII with excess t-BuOK at 25°C in THF results in a mixture of η6-(Xa) and η5-anions (XI), the former predominating. 相似文献
18.
Fu-Ling Xue Jian-Xiao Li Zhao-Yang Wang Jin-Feng Xiong Di Li 《Research on Chemical Intermediates》2013,39(3):1153-1168
Using KF as base and THF as solvent, different 5-alkoxy-3,4-dibromo-2(5H)-furanones were reacted with amines containing a benzene ring structure by Michael addition–elimination reaction at room temperature or 40 °C to give twenty-three 5-alkoxy-4-amino-3-bromo-2(5H)-furanones containing benzene rings, with yields of 21–86 % (mostly over 64 %). The structures of all the newly synthesized compounds were elucidated and confirmed by FTIR, UV, 1H NMR, 13C NMR, and mass spectroscopy, elemental analysis, and X-ray single-crystal diffraction. This rapid synthesis of the series of 2(5H)-furanones derivatives with different bioactive units is not only an important synthetic strategy for 2(5H)-furanone derivatives but also a basis for synthesis of potential drug molecules for activity testing. 相似文献
19.
S. Franklin T. Balasubramanian Babu Varghese 《Acta Crystallographica. Section C, Structural Chemistry》2009,65(2):o62-o65
<!?tpct=1pt>Racemic malic acid and trimethoprim [5‐(3,4,5‐trimethoxybenzyl)pyrimidine‐2,4‐diamine] form a 1:2 salt (monoclinic, P21/c), 2C14H19N4O3+·C4H4O52−, in which the malate component is disordered across a centre of inversion. The crystal structure of the salt consists of protonated trimethoprim residues and a malate dianion. The carboxylate group of the malate ion interacts with the trimethoprim cation in a linear fashion through pairs of N—H...O hydrogen bonds to form a cyclic hydrogen‐bonded motif. This is similar to the carboxylate–trimethoprim cation interaction observed earlier in the complex of dihydrofolate reductase with trimethoprim. The structure of the salt of trimethoprim with racemic dl ‐malic acid reported here is the first of its kind. The present study investigates the conformations and the hydrogen‐bonding interactions, which are very important for biological functions. The pyrimidine plane makes a dihedral angle of 78.08 (7)° with the benzene ring of the trimethoprim cation. The cyclic hydrogen‐bonded motif observed in this structure is self‐organized, leading to novel types of hydrogen‐bonding motifs in supramolecular patterns. 相似文献
20.
The reaction of 6-bromo-1-hexene with Mg was studied in order to obtain information on the role of the solvent during the formation of Grignard reagents. The 5-hexenyl radical (Rnc.) is known to cyclize rapidly and irreversibly to the cyclopentylmethyl radical (Rc.). Changes in yields of the cyclized and non-cyclized Grignard compounds have been found on varying the solvent. Information on the radical pairs involved is obtained from the yields of the three possible coupling products (RncRnc, RncRc and RcRc). Results are correlated to the intensity of the CIDNP spectra of the Grignard compounds. It is found that basicity and viscosity of the solvents influence the reactions at the site of single electron transfer. Formation of Grignard compounds via radical pairs increases: (a) with decreasing basicity of the solvent, (b) with decreasing viscosity of the solvent, and (c) on dilution of THF with benzene. It is proposed that interaction between the radical and the π-electron rich solvent benzene plays a role in reactions run in Bz/THF mixtures. 相似文献