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1.
Stíbr B Holub J Bakardjiev M Pavlík I Tok OL Císarová I Wrackmeyer B Herberhold M 《Chemistry (Weinheim an der Bergstrasse, Germany)》2003,9(10):2239-2244
The reaction of nido-[7,8,9-PC(2)B(8)H(11)] (1) with [[CpFe(CO)(2)](2)] (Cp=eta(5)-C(5)H(5) (-)) in benzene (reflux, 3 days) gave an eta(1)-bonded complex [7-Fp-(eta(1)-nido-7,8,9,-PC(2)B(8)H(10))] (2; Fp=CpFe(CO)(2); yield 38 %). A similar reaction at elevated temperatures (xylene, reflux 24 h) gave the isomeric complex [7-Fp-(eta(1)-nido-7,9,10-PC(2)B(8)H(10))] (3; yield 28 %) together with the fully sandwiched complexes [1-Cp-closo-1,2,4,5-FePC(2)B(8)H(10)] 4 a (yield 30%) and [1-Cp-closo-1,2,4,8-FePC(2)B(8)H(10)] 4 b (yield 5%). Compounds 2 and 3 are isolable intermediates along the full eta(5)-complexation pathway of the phosphadicarbaborane cage; their heating (xylene, reflux, 24 h) leads finally to the isolation of compounds 4 a (yields 46 and 52%, respectively) and 4 b (yields 4 and 5%, respectively). Moreover, compound 3 is isolated as a side product from the heating of 2 (yield 10%). The structure of compound 4 a was determined by an X-ray structural analysis and the constitution of all compounds is consistent with the results of mass spectrometry and IR spectroscopy. Multinuclear ((1)H, (11)B, (31)P, and (13)C), two-dimensional [(11)B-(11)B]-COSY, and (1)H[(11)B(selective)] magnetic resonance measurements led to complete assignments of all resonances and are in excellent agreement with the structures proposed. 相似文献
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Dr. Przemysław J. Malinowski Prof. Dr. Ingo Krossing 《Angewandte Chemie (International ed. in English)》2014,53(49):13460-13462
Attempts to prepare Fe(CO)5+ from Ag[Al(ORF)4] (RF=C(CF3)3) and Fe(CO)5 in CH2Cl2 yielded the first complex of a neutral metal carbonyl bound to a simple metal cation. The Ag[Fe(CO)5]2+ cation consists of two Fe(CO)5 molecules coordinating Ag+ in an almost linear fashion. The ν(CO) modes are blue‐shifted compared to Fe(CO)5, with one band above 2143 cm?1 indicating that back‐bonding is heavily decreased in the Ag[Fe(CO)5]2+ cation. 相似文献
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Braga D Polito M Bracaccini M D'Addario D Tagliavini E Proserpio DM Grepioni F 《Chemical communications (Cambridge, England)》2002,(10):1080-1081
The bidentate sandwich ligand [Fe(eta 5-C5H(4)-1-C5H4N)2] has been prepared, structurally characterized and employed in the preparation of the novel supramolecular heterobimetallic metalla-macrocycles [Fe(eta 5-C5H(4)-1-C5H4N)2]Ag2(NO3)(2).1.5H2O, [Fe(eta 5-C5H(4)-1-C5H4N)2]Cu2(CH3COO)(4).3H2O and [Fe(eta 5-C5H(4)-1-C5H4N)2]Zn2Cl4. 相似文献
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D. P. Krut’ko M. V. Borzov Long Yu Liao Wan Li Nie A. V. Churakov J. A. K. Howard D. A. Lemenovskii 《Russian Chemical Bulletin》2006,55(9):1574-1580
The new side-chain functionalized cyclopentadienyl ligand LiC5H4CPh2CH2R (R is 1-methylimidazol-2-yl) as lithium salt 2, the trimethylsilyl derivative Me3SiC5H4CPh2CH2R (3), and the ligand in the CH form (4) were prepared starting from 6,6-diphenylfulvene and 1,2-dimethylimidazole lithiated at the 2-Me group (1) and then characterized. The half-sandwich complexes (η5:η 1-C5H4CPh2CH2R)TiCl3 (5) and (η5:η 1-C5H4CPh2CH2R)ZrCl3 (6) were synthesized. The molecular structure of complex 5 was established by X-ray diffraction. Complexes 5 and 6 exhibit dynamic behavior in solution associated with degenerate interconversion of the pseudo-six-membered metallacycle.
For titanium complex 5 in a solvating solvent, a dynamic process due to intramolecular dissociation—coordination of the imidazole fragment was observed.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1518–1524, September, 2006. 相似文献
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Binbin Zhou Dr. Jose M. Goicoechea 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(36):11145-11150
Reaction of cyclooctatetraene (COT) iron(II) tricarbonyl, [Fe(cot)(CO)3], with one equivalent of K4Ge9 in ethylenediamine (en) yielded the cluster anion [Ge8Fe(CO)3]3? which was crystallographically‐characterized as a [K(2,2,2‐crypt)]+ salt in [K(2,2,2‐crypt)]3[Ge8Fe(CO)3]. The chemically‐reduced organometallic species [Fe(η3‐C8H8)(CO)3]? was also isolated as a side‐product from this reaction as [K(2,2,2‐crypt)][Fe(η3‐C8H8)(CO)3]. Both species were further characterized by EPR and IR spectroscopy and electrospray mass spectrometry. The [Ge8Fe(CO)3]3? cluster anion represents an unprecedented functionalized germanium Zintl anion in which the nine‐atom precursor cluster has lost a vertex, which has been replaced by a transition‐metal moiety. 相似文献
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Lousada CM Pinto SS Lopes JN da Piedade MF Diogo HP da Piedade ME 《The journal of physical chemistry. A》2008,112(13):2977-2987
The standard molar enthalpies of sublimation of ferrocene, 1,1'-dimethylferrocene, decamethylferrocene, ferrocenecarboxaldehyde and alpha-methylferrocenemethanol, and the enthalpy of vaporization of N,N-dimethyl(aminomethyl)ferrocene, at 298.15 K, were determined by Calvet-drop microcalorimetry and/or the Knudsen effusion method. The obtained values were used to assess and refine our previously developed force field for metallocenes. The modified force field was able to reproduce the deltasubHdegreesm and deltavapHdegreesm values of the test-set with an accuracy better than 5 kJ.mol-1, except for decamethylferrocene, in which case the deviation between the calculated and experimental deltasubHdegreesm values was 16.1 kJ.mol-1. The origin of the larger error found in the prediction of the sublimation energetics of decamethylferrocene, and which was also observed in the estimation of structural properties (e.g., density and unit cell dimensions), is discussed. Finally, the crystal structures of Fe(eta5-C5H4CH3)2 and Fe[(eta5-(C5H5)(eta5-C5H4CHO)] at 293 and 150 K, respectively, are reported. 相似文献
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Capon JF Ezzaher S Gloaguen F Pétillon FY Schollhammer P Talarmin J 《Chemistry (Weinheim an der Bergstrasse, Germany)》2008,14(6):1954-1964
Electrochemical investigations on a structural analogue of the [2Fe](H) subsite of [FeFe]H(2)ases, namely, [Fe(2)(CO)(6){micro-SCH(2)N(CH(2)CH(2)- OCH(3))CH(2)S}] (1), were conducted in MeCN/NBu(4)PF(6) in the presence of HBF(4)/Et(2)O or HOTs. Two different catalytic proton reduction processes operate, depending on the strength and the concentration of the acid used. The first process, which takes place around -1.2 V for both HBF(4)/Et(2)O and HOTs, is limited by the slow release of H(2) from the product of the {2 H(+)/2 e} pathway, 1-2H. The second catalytic process, which occurs at higher acid concentrations, takes place at different potentials depending on the acid present. We propose that this second mechanism is initiated by protonation of 1-2H when HBF(4)/Et(2)O is used, whereas the reduction of 1-2H is the initial step in the presence of the weaker acid HOTs. The potential of the second process, which occurs around -1.4 V (reduction potential of 1-3H(+)) or around -1.6 V (the reduction potential of 1-2H) is thus dependent on the strength of the available proton source. 相似文献
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Henri Brunner Rainer Lukas Annamaria Woditsch 《Journal of organometallic chemistry》1978,161(2):C49-C52
(η-C5H5)(CO)2W[(η3-C5H5)(C5H5)2], I, containing two tilted five-membered rings, is converted into the bridged ferrocene derivative (η-C5H5)(CO)2W{(η3-C5H5)}[(η-C5 H4)2Fe]} II by successive reaction with Na and FeCl2. 相似文献
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Michel O. Albers Neil J. Coville Eric Singleton 《Journal of organometallic chemistry》1982,232(3):261-266
The reaction between Fe(CO)5, and group V donor ligands L, (L PPh3, AsPh3, SbPh3, PMePh2, PMe2Ph, Asme2Ph, P(C6H11)3, P(n-Bu)3, P(i-Bu)3, P(OPh)3, P(OEt)3, P(OMe)3) in the presence of [(η5-C5Me5Fe(CO)2]2 (R H, Me) or [(η5-C5Me5)Fe(CO)2]2 as catalyst in refluxing toluene, rapidly gives the complexes Fe(CO)4L in yields > 85%. The reaction rate is essentially independent of the nature of L for [(η5-C5Me5)Fe(CO)2]2 as catalyst. For the other catalysts, the rate is influenced predominantly by the steric properties of L. These results are interpreted in terms of the interaction between the catalyst and the ligand L to give derivatives of the type (η5-C5H4R)2Fe2,(CO)3,(L). These derivatives were also found to catalyse the reaction between Fe(CO)5, and L. The complexes [(η-C5H4R)Fe(CO)2]2 (R H, Me) and [(η5-C5Me5)Fe(CO)2]2 also catalyse the reaction between Mn2(CO)10 and PPh3 to give Mn2(CO)8- PPh3)2 in > 80% yield. 相似文献
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Alvarez CM Alvarez MA Alonso M García ME Rueda MT Ruiz MA Herson P 《Inorganic chemistry》2006,45(23):9593-9606
The phosphide-bridged dimolybdenum complexes (H-DBU)[Mo2Cp2(mu-PR2)(CO)4] (R= Cy, Ph; DBU = 1,8-diazabicyclo[5.4.0.]undec-7-ene) react with p-benzoquinone to give the hemiquinone complexes [Mo(2)Cp2(OC6H4OH)(mu-PR2)(CO)4]. The latter experience facile homolytic cleavage of the corresponding Mo-O bonds and react readily at room temperature with HSPh or S2Ph2 to give the thiolate complexes [Mo2Cp2(mu-PCy2)(mu-SPh)(CO)4] or [Mo2Cp2(mu-PR2)(mu-SPh)(CO)2]. In contrast, PRH-bridged substrates experience overall insertion of quinone into the P-H bond to give the anionic compounds (H-DBU)[Mo(2)Cp2{mu-PR(OC6H4OH)}(CO)4], which upon acidification yield the corresponding neutral hydrides. The cyclohexyl anion experiences rapid nucleophilic displacement of the hemiquinone group by different anions ER- (ER = OH, OMe, OC4H5, OPh, SPh) to give novel anionic compounds (H-DBU)[Mo2Cp2{mu-PCy(ER)}(CO)4], which upon acidification yield the corresponding neutral hydrides. The structure of four of these hydride complexes [PPh(OC6H4OH), PCy(OH), PCy(OMe), and PCy(OPh) bridges] was determined by X-ray diffraction methods and confirmed the presence of cis and trans isomers in several of these complexes. In addition, it was found that the hydroxyphosphide anion [Mo2Cp2{mu-PCy(OH)}(CO)4]- displays in solution an unprecedented tautomeric equilibrium with its hydride-oxophosphinidene isomer [Mo2Cp2(mu-H){mu-PCy(O)}(CO)4]-. 相似文献
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del Mar Conejo M Fernández R del Río D Carmona E Monge A Ruiz C Márquez AM Sanz JF 《Chemistry (Weinheim an der Bergstrasse, Germany)》2003,9(18):4452-4461
The beryllocenes [Be(C(5)Me(4)H)(2)] (1), [Be(C(5)Me(5))(2)] (2), and [Be(C(5)Me(5))(C(5)Me(4)H)] (3) have been prepared from BeCl(2) and the appropriate KCp' reagent in toluene/diethyl ether solvent mixtures. The synthesis of 1 is facile (20 degrees C, overnight), but generation of decamethylberyllocene 2 demands high temperatures (ca. 115 degrees C) and extended reaction times (3-4 days). The mixed-ring beryllocene 3 is obtained when the known [(eta(5)-C(5)Me(5))BeCl] is allowed to react with K[C(5)Me(4)H], once more under somewhat forcing conditions (115 degrees C, 36 h). The structures of the three metallocenes have been determined by low-temperature X-ray studies. Both 1 and 3 present eta5/eta1 geometries of the slip-sandwich type, whereas 2 exhibits an almost regular, ferrocene-like, sandwich structure. In the mixed-ring compound 3, C(5)Me(5) is centrally bound to beryllium and the eta(1)-C(5)Me(4)H ring bonds to the metal through the unique CH carbon atom. This is also the binding mode of the eta(1)-ring of 1. To analyze the nature of the bonding in these molecules, theoretical calculations at different levels of theory have been performed on compounds 2 and 3, and a comparison with the bonding in [Be(C(5)H(5))(2)] has been made. As for the latter molecule, energy differences between the eta5/eta5 and the eta5/eta1 structures of 2 are very small, being of the order of a few kcal mol(-1). Constrained space orbital variations (CSOV) calculations show that the covalent character in the bonding is larger for [Be(C(5)Me(5))(2)] than for [Be(C(5)H(5))(2)] due to larger charge delocalization and to increased polarizability of the C(5)Me(5) fragment. 相似文献
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Synthesis and Crystal Structure of [C(NMe2)3]2[(CO)4Fe(μ‐InCl2)2Fe(CO)4] Treatment of [C(NMe2)3]2[(CO)4FeInCl3] ( 1 ) with hot water produces the dinuclear complex [C(NMe2)3]2[(CO)4Fe(μ‐InCl2)2Fe(CO)4] ( 2 ) which could be crystallized from dichloromethane/pentane. 2 crystallizes in the monoclinic space group P21/n with a = 835.7(1), b = 1187.8(1), c = 1902.7(1) pm, β = 91.877(5)° and Z = 2. The anion contains a four‐membered Fe—In—Fe—In ring with octahedral environment at the iron atom and tetrahedral coordination at the In atom. 相似文献
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Donghi D Beringhelli T D'Alfonso G Mondini M 《Chemistry (Weinheim an der Bergstrasse, Germany)》2006,12(4):1016-1025
The interaction of fluorinated alcohols with the anionic hydrido complex [HRe2(CO)9]- (1) has been investigated by NMR spectroscopy. According to the acidic strength of the alcohols, the interaction may result not only in the formation of dihydrogen-bonded ROH...[HRe2(CO)9]- adducts 2, but also in proton transfer to give the neutral species [H2Re2(CO)9] (3). With the weaker acid trifluoroethanol (TFE) evidence for the occurrence of the dihydrogen-bonding equilibrium was obtained by 2D 1H NOESY. The dependence of the hydride chemical shift on TFE concentration at different temperatures provided values for the constants of this equilibrium, from which the thermodynamic parameters were evaluated as deltaH(degrees) = -2.6(2) kcal mol(-1), deltaS(degrees) = -9.3(2) cal mol(-1) K(-1). This corresponds to a rather low basicity factor (E(j) = 0.64). Variable-temperature T1 measurements allowed the proton-hydride distance in adduct 2 a to be estimated (1.80 angstroms). In the presence of hexafluoroisopropyl alcohol (HFIP) simultaneous occurrence of both dihydrogen-bonding and proton-transfer equilibria was observed, and the equilibria shifted versus the protonated product 3 with increasing HFIP concentration and decreasing temperature. Reversible proton transfer between the alcohol and the hydrido complex occurs on the NMR timescale, as revealed by a 2D 1H EXSY experiment at 240 K. For the more acidic perfluoro-tert-butyl alcohol (PFTB) the protonation equilibrium was further shifted to the right. Thermal instability of 3 prevented the acquisition of accurate thermodynamic data for these equilibria. The occurrence of the proton-transfer processes (in spite of the unfavorable pK(a) values) can be explained by the formation of homoconjugated RO...HOR- pairs which stabilize the alcoholate anions. 相似文献