共查询到20条相似文献,搜索用时 15 毫秒
1.
Methyl 13-(2-cyclopentenyl)tridecanoate (chaulmoograte) and methyl 13-(2-cyclopentenyl)-cis-6-tridecenoate (gorlate) were hydrogenated using palladium on barium sulfate in hexane. Products obtained by partial hydrogenations were fractionated by argentation thin-layer chromatography, and the components characterised and quantitatively analysed by gas-liquid chromatography, nuclear magnetic resonance spectroscopy, infrared spectroscopy, and reductive ozonolysis. The double bond in position 2 of the cyclopentene ring was found to shift to both positions 1 and 3, but the double bond in position 1 was saturated slower than that either in position 2 or 3. Isomerisation of the ring double bond was faster than its saturation. In methyl gorlate trans-double bonds in the chain accumulated due to their faster formation and slower hydrogenation than cis-double bonds. Saturation of the ring double bond was faster than that of the chain double bond. 相似文献
2.
Hideo Kurosawa Kenjin Shiba Kazuyoshi Hirako Isao Ikeda 《Inorganica chimica acta》1996,250(1-2):149-154
Some (η3-crotyl) (2,5-dichlorophenyl)palladium(II) complexes containing phosphine and phosphite ligands Pd(η3-CH2CH-CHMe)(Ar)(PR3) (Ar = C6H3Cl2-2,5) were isolated as crystalline solids or generated in solution. These existed as a mixture of two geometrical isomers arising from a different way of risposition of the crotyl-methyl group and the aryl ligand. The electronic nature of the PR3 ligand controlled the relative rates of the interconversion between the two isomers and the reductive elimination of the complexes which released MeCH=CHCH2Ar and CH2=CHCH(Me)(Ar). Electron-withdrawing phosphite ligands were particularly effective in enhancing the reductive elimination rate, making the contribution of the isomerization path almost negligible and allowing the formation of two coupling products to be followed separately by spectroscopic means. The observations demonstrated the occurrence of C---C coupling between mutually cis carbon ligands in (η3-allyl)(hydrocarbyl)palladium(II) complexes. The η1-crotyl complex, (Pd(η1-CH2CH=CHMe)(Ar) (dppen) (dppen = cis-Ph2PCH=CHPPh2) was isolated and shown to exist as a sole regio-isomer in solution. Reductive elimination of this η1-crotyl complex gave MeCH=CHCH2Ar exclusively. 相似文献
3.
Two crystalline forms of (dithiodiphenylphosphinate)(phenyl)(triphenylphosphine)-palladium(II) (C36H30P2PdS2), one without solvent, the other containing THF (C4H8O), are obtained after reaction of sodium diphenyldithiophosphinate with (phenyl) (bis-triphenylphosphine) palladium(II) chloride and crystallisation from two different solvent mixtures. The molecular structures, as determined by single crystal X-ray diffraction, differ in the planarity of the 4-membered palladium dithiophosphinate rings. The experimental conformations have been compared to the conformations of four-membered metal-S2P rings reported in the Cambridge Structural Database. A flat conformation is more common than a puckered one. DFT calculations at the B3LYP level of theory indicate that the flat conformation of a model metallodithiophosphinate ring is very slightly lower in energy (1.2 kcal/mol) than the puckered conformation. 相似文献
4.
In a synthetic route that varies from the standard procedure requiring irradiation, the (η6-C6H5Cl)Cr(CO)2PPh3 complex is obtained upon reacting (η6-C6H5Cl)Cr(CO)3 with tetrakis(triphenylphosphine)palladium(0), CuI, and trimethylsilylphenylacetylene in triethylamine. The X-ray crystal structure of the yellow–orange crystals of (η6-C6H5Cl)Cr(CO)2PPh3 allows structural comparisons to related (arene)Cr(CO)2PR3 complexes. 相似文献
5.
Michael Brands Hans G. Wey Richard Goddard Holger Butenschn 《Inorganica chimica acta》1994,220(1-2):175-186
Tricarbonyl(η6-1-oxobenzocyclobutene)chromium(0) (1) can be transformed to tricarbonyl(η6-1-endo-hydroxybenzocyclobutene) chromium(0) derivatives with substituents R (R=CH3, CH=CH2, (CH2)4CH=CH2, (CH2)4OSi(Me)2tBu) at Cl on the exo face of the complex. The relative configuration is proven by an X-ray crystal structure analysis of the trimethylsilyl ether 8 (C16H18CrO4Si: a=8.693(1), b=9.490(1), c=11.063(1) Å, =97.51(1), β=110.32(1), γ=95.38(1)°, triclinic, space group P
(No.2), R=0.037, Rw=0.052 for 4609 observed reflections. Attempts directed at an intramolecular cycloaddition of the ortho-quinodimethane complex derived from 17 by anion promoted ring opening unexpectedly resulted in the formation of 12 as the product of an opening of the proximal bond of the anellated ring located between the hydroxy group and the coordinated aromatic ring in 16. The fact that the intermolecular cycloaddition reaction for 16 is possible in the presence of a dienophile is taken as evidence for an equilibrium between the alcoholate 17 and the two ring opened products 16 and 18. The proximal ring opening of 6 is not observed when the free organic ligand 21 is used as the educt. Ketone complexes 1 and 25 undergo proximal ring opening reaction when treated with alcoholate or primary amines. 相似文献
6.
Romagnoli R Baraldi PG Carrion MD Cara CL Cruz-Lopez O Preti D Tolomeo M Grimaudo S Di Cristina A Zonta N Balzarini J Brancale A Sarkar T Hamel E 《Bioorganic & medicinal chemistry》2008,16(10):5367-5376
Chalcones are characterized by possessing an enone moiety between two aromatic rings. A series of chalcone-like agents, in which the double bond of the enone system is embedded within a thiophene ring, were synthesized and evaluated for antiproliferative activity and inhibition of tubulin assembly and colchicine binding to tubulin. The replacement of the double bond with a thiophene maintains antiproliferative activity and therefore must not significantly alter the relative conformation of the two aryl rings. The synthesized compounds were found to inhibit the growth of several cancer cell lines at nanomolar to low micromolar concentrations. In general, all compounds having significant antiproliferative activity inhibited tubulin polymerization with an IC(50)<2microM. Several of these compounds caused K562 cells to arrest in the G2/M phase of the cell cycle. 相似文献
7.
《Inorganica chimica acta》2004,357(14):4165-4171
Cationic palladium(II) complexes [PdCl{PR2CH2C(But)NNC(But)CH2PR2}]Cl, where R = isopropyl, cyclohexyl or tert-butyl, were synthesized by the reactions of the corresponding diphosphinoazines with bis(acetonitrile)palladium(II) dichloride. When bis(benzonitrile)palladium(II) dichloride was used instead, in the molar ratio of 2:1 to the diphosphinoazine, a new complex was isolated with the isopropyl ligand showing a previously unknown (E,E) tetradentate coordination mode. Crystal and molecular structure was determined by X-ray diffraction. The solid complex was a racemate of two axially chiral enantiomers and the chirality was preserved in solution. Reactions of the cationic complexes with triethylamine gave complexes [PdCl{PR2CHC(But)NNC(But)CH2PR2}], containing deprotonated diphosphinoazines in ene-hydrazone unsymmetrical pincer-like configuration. The complexes represent several of the still rare examples of Pd(II) amido bis(phosphine) complexes with a chlorine atom covalently bonded trans to the amide nitrogen. 相似文献
8.
Paul Nguyen Zheng Yuan Lisa Agocs Gerald Lesley Todd B. Marder 《Inorganica chimica acta》1994,220(1-2):289-296
A series of symmetric 1, 4-bis(p-R-phenylethynyl)benzenes (6a-h) have been prepared via Pd11/Cu1 catalyzed cross- coupling of 1, 4-diiodobenzene (5) and p-substituted phenylethynes (4a-h). Similarly, the unsymmetric analogues (9a-c) were obtained from 1-iodo-4-(p-nitrophenylethynyl)benzene (8) and p-substituted phenylethynes (4c, 4d, 4g). Quantitative analysis of 1,4-(trimethylsilyl)butadiyne (10), produced in the catalytic coupling of ethynyltri- methylsilane with aryl halides using PdCl2(PPh3)2/CuI in an amine solvent, confirmed that catalyst initiation proceeds via reduction of Pd11 to Pd0 with concomitant oxidative homo-coupling of two ethynyltrimethylsilane molecules producing exactly one equivalent of 10 based on Pd11. If air is present, the PdCl2(PPh3)2/CuI/amine mixture provides a very effective system for catalytic oxidative homo-coupling of terminal alkynes to diynes and thus air must be rigorously excluded from the cross-coupling reactions. Hydrodehalogenation can compete effectively with the cross-coupling reaction for highly fluorinated aryl halides. Under certain conditions, the fluorinated aryl bromide or iodide can serve as the oxidant for the alkyne to diyne oxidative homo-coupling reaction. This can be avoided by appropriate choice of reaction conditions and reagents. These competing pathways have significant implications for the cross-coupling of aryl halides with terminal alkynes and are discussed herein. 相似文献
9.
Three types of catalytic system based on palladium complexes were studied in the synthesis of alkynylcarboxylic acid esters by oxidative carbonylation of monosubstituted alkynes. Three mechanisms were proposed for activation of the ≡C---H bond in alkynes and the formation of RC≡C[Pd]X, a key intermediate: (i) electrophilic substitution of H+ by Cu(I), (ii) electrophilic substitution of H+ by I+, and (iii) oxidative addition of the C---H bond in alkynes to palladium. 相似文献
10.
Florian Kessler 《Inorganica chimica acta》2011,374(1):278-6282
The platinum(0) complex [Pt(PPh3)4] reacts with brominated propargylic amides and esters in benzene by oxidative addition to give trans-[Br(PPh3)2Pt-CC-C(O)R] complexes whereas no reaction occurs when halogenated solvents (CH2Cl2, CHCl3) are used. The cis-ligands PPh3 can be replaced by P(iPr)3 and the bromide by trifluoroacetate. O-Alkylation of those trans-[X(PR′3)2Pt-CC-C(O)R] complexes (X = Br, CF3COO; R′ = Ph, iPr) derived from propargylic amides with MeOTf or [Me3O]BF4 in CH2Cl2 gives the first cationic monoallenylidene complexes of platinum, trans-[X(PR′3)2PtCCC(OMe)NR2]+Y− (Y = OTf, BF4). In contrast, trans-[Br(PPh3)2Pt-CC-C(O)OMenthyl] derived from a propargylic ester does not react with MeOTf in CH2Cl2. However, in acetonitrile instead of O-methylation the substitution of acetonitrile for the bromide ligand to yield the cationic acetonitrile alkynyl platinum complex trans-[MeCN(PPh3)2Pt-CC-C(O)OMenthyl]+OTf− is observed. The related palladium complexes trans-[X(PR′3)2Pd-CC-C(O)OR] (X = Br, CF3COO; R′ = Ph, iPr, R = menthyl, Et) react with MeOTf or [Et3O]BF4 analogously affording trans-[MeCN(PR′3)2Pd-CC-C(O)OR]+Y− (Y = OTf, BF4). 相似文献
11.
The allylidene complex (CO)5W=CH---C(Ph)=C(Ph)H (4) reacts with cyclopentadiene by stereospecific transfer of the carbene ligand to one of the two double bonds of cyclopentadiene to give a cis-divinylcyclopropane complex 5. The divinylcyclopropane ligand coordinates to the metal via the unsubstituted double bond. Addition of bromide to solutions of 5 gives rise to the formation of [(CO)5WBr]− and a bicyclo[3.2.1]octadiene (6), the Cope rearrangement product of the free divinylcyclopropane. Thermolysis of 5 affords 6 and its (CO)5W complex. The reaction of 4 with furan (8a), 2-methylfuran (8b) and 3-methylfuran (8c) affords the (CO)5W(bicyclo[3.2.1]oxahepta- diene) complexes (9a–c), The formation of 9a–c which is chemo-, regio- and stereospecific is explained by a tandem cyclopropanation/Cope rearrangement sequence. The bicyclic ligands 10a–c are liberated from the metal either by thermolysis of solutions of 9a–c or by addition of bromide. 相似文献
12.
Donato Monti Giuseppe Frachey Mauro Bassetti Anthony Haynes Glenn J. Sunley Peter M. Maitlis Andrea Cantoni Gabriele Bocelli 《Inorganica chimica acta》1995,240(1-2):485-493
The reactions of complex (C5Me5)Ir(Cl) (CO) (Me) (1a) with cyclohexylisocyanide and phosphines (L=CyNC, PHPh2, PMePh2, PMe2Ph) give the products of alkyl migratory insertion (C5Me5Ir(Cl) (COMe) (L), in toluence or tetrahydrofuran at 323 K or higher temperature. The phenyl analogue (C5Me5)Ir(Cl)(CO)(Ph) or the iodide complexes (C5Me5)Ir(I) (CO) (R) (R=Me, Ph_are not reactive under the same conditions. The reaction of (C5Me5)Ir(Cl)(CO)(Me) with PMePh2 and PMe2Ph in acetonitrile yields the chloride substitution product [(C5Me5)Ir(CO)(L)(Me)]+Cl−. Kinetic measurements for the reactions of (C5Me5)Ir(Cl)(CO)(Me) in toluene are first order in the iridium complex and exhibit a saturation dependence on the incoming donors L. Analysis of the data suggests a two-step process involving (i) rapid formation of a molecular complex [(C5Me5)Ir(Cl)(CO)(Me), (L)], in which the structure of 1a is unperturbed within the limits of spectroscopic analysis, and (ii) rate determining methyl migration. The reaction parameters are K for the pre-equilibrium step (K = 1.5 (CyNC), 7.3 (PHPh2), 7.1 (PMePh2) dm3 mol−1 at 323 K) and k2 for the slow carbon---carbon bond formation (k2 (105) = 6.9 (CyNC), 1.2 (PHPh2), 1.0 (PMePh2) s−1 at 323 K). The activation parameters for the methyl migration step in the reaction with PMePh2 obtained between 308 and 338 K, are ΔH≠ = 106±16 kJ mol−1 and ΔS≠ = − 14±5 J K−1 mol−1. The reaction of 1a with PMePh2 proceeds at similar rates in tetrahydrofuran (K = 3.7 dm3 mol−1, k2 (105) = 1.2 s−1, 323 K). The crystal structure of (C5Me5)Ir(Cl)(COMe) (PMe2Ph) has been determined by X-ray diffraction. C20H29ClOPIr: Mr = 544.1, monoclinic, P21/n, A = 8.084 (2), B = 9.030(2), C = 28.715 (3) Å, β = 91.41 (3)°, Z = 4, Dc = 1.71 g cm−3, V = 2095.5 Å3, room temperatyre, Mo K, γ = 0.71069, μ = 65.55 cm−1, F(000) = 1044, R = 0.037 for 2453 independent observed reflections. The complex shows a deformed tetrahedral coordination assuming the η5-C5Me5 molecular fragment as a single coordination site. The iridium-chlorine bond is staggered with respect to two adjacent C(ring)-methyl bonds, while the Ir---P and the Ir---COMe bonds are eclipsed with respect to C(ring)-methyl bonds. 相似文献
13.
Iminophosphinite pincer palladium complexes were synthesized and evaluated as potential catalysts in the Suzuki coupling reactions of phenylboronic acid and various aryl halides. The iminophosphinite ligands were synthesized through condensation reactions between 2-bromo-3-hydroxybenzaldehyde and 2,4,6-trimethylaniline and 2,6-diisopropylaniline, followed by phosphorylation with chlorodiphenylphosphine and chlorodicyclohexylphosphine. Oxidative addition of the pincer ligands to Pd2(dba)3 afforded palladium iminophosphinite complexes [(2-(CHNR)-6-(OPR′2)C6H3)PdBr] (R = 2,6-iPr2C6H3, R′ = Ph (2a) or Cy (2b); R = 2,4,6-Me3C6H2, R′ = Ph (2c) or Cy (2d)). Reaction of 2b and silver trifluoroacetate gave the corresponding iminophosphinite palladium trifluoroacetate (3). The solid state structures of 2a, 2d, and 3 were determined by X-ray single crystal diffraction studies. 相似文献
14.
Anthony Haynes Jean M. Pearson Paul W. Vickers Jonathan P.H. Charmant Peter M. Maitlis 《Inorganica chimica acta》1998,270(1-2):382-391
Carbonylation of the anionic iridium(III) methyl complex, [MeIr(CO)2I3]− (1) is an important step in the new iridium-based process for acetic acid manufacture. A model study of the migratory insertion reactions of 1 with P-donor ligands is reported. Complex 1 reacts with phosphites to give neutral acetyl complexes, [Ir(COMe)(CO)I2L2] (L = P(OPh)3 (2), P(OMe)3 (3)). Complex 2 has been isolated and fully characterised from the reaction of Ph4As[MeIr(CO)2I3] with AgBF4 and P(OPh)3; comparison of spectroscopic properties suggests an analogous formulation for 3. IR and 31P NMR spectroscopy indicate initial formation of unstable isomers of 2 which isomerise to the thermodynamic product with trans phosphite ligands. Kinetic measurements for the reactions of 1 with phosphites in CH2Cl2 show first order dependence on [1], only when the reactions are carried out in the presence of excess iodide. The rates exhibit a saturation dependence on [L] and are inhibited by iodide. The reactions are accelerated by addition of alcohols (e.g. 18× enhancement for L = P (OMe)3 in 1:3 MeOH-CH2Cl2). A reaction mechanism is proposed which involves substitution of an iodide ligand by phosphite, prior to migratory CO insertion. The observed rate constants fit well to a rate law derived from this mechanism. Analysis of the kinetic data shows that k1, the rate constant for iodide dissociation, is independent of L, but is increased by a factor of 18 on adding 25% MeOH to CH2Cl2. Activation parameters for the k1 step are ΔH≠ = 71 (±3) kJ mol−, ΔS≠ = −81 (±9) J mol−1 K−1 in CH2Cl2 and ΔH≠ = 60(±4) kJ mol−1, ΔS≠ = −93(± 12) J mol−1 K−1 in 1:3 MeOH-CH2Cl2. Solvent assistance of the iodide dissociation step gives the observed rate enhancement in protic solvents. The mechanism is similar to that proposed for the carbonylation of 1. 相似文献
15.
The P---C bond splitting reaction of Ru(OAc)2(Binap), containing 13C=O-enriched acetate, with 2 equiv. of triflic acid at 80 °C, has been studied. NMR spectroscopy (and specifically 13C NMR data) reveal that acetic anhydride and water are produced, thus explaining the end product, which may be thought of as developing due to water adding across the P---C bond. An intermediate 10 derived from attack of acetate on a P-atom is recognised. Complex 10 is shown to contain a cyclic five-membered ring, Ru---{(P---OC(Me)(=O)} fragment which develops via acetate attack on a P-atom. Crystal structures for two Ru(OAc)2(MeO---Biphep) derivatives are reported. 相似文献
16.
Inhibition of LDL oxidation by flavonoids in relation to their structure and calculated enthalpy 总被引:8,自引:0,他引:8
Vaya J Mahmood S Goldblum A Aviram M Volkova N Shaalan A Musa R Tamir S 《Phytochemistry》2003,62(1):89-99
Twenty flavonoid compounds of five different subclasses were selected, and the relationship of their structure to the inhibition of low-density lipoprotein (LDL) oxidation in vitro was investigated. The most effective inhibitors, by either copper ion or 2,2'-azobis (2-amidino-propane) dihydrochloride (AAPH) induction, were flavonols and/or flavonoids with two adjacent hydroxyl groups at ring B. In the presence of the later catechol group, the contribution of the double bond and the carbonyl group at ring C was negligible. Isoflavonoids were more effective inhibitors than other flavonoid subclasses with similar structure. Substituting ring B with hydroxyl group(s) at 2' position resulted in a significantly higher inhibitory effect than by substituting ring A or ring B at other positions. The type of LDL inducer had no effect in flavonoids with catechol structure. Calculated heat of formation data (deltadeltaH(f)) revealed that the donation of a hydrogen atom from position 3 was the most likely result, followed by that of a hydroxyl from ring B. Position 3 was favored only in the presence of conjugated double bonds between ring A to ring B. This study makes it possible to assign the contribution of different functional groups among the flavonoid subclasses to in vitro inhibition of LDL oxidation. 相似文献
17.
Annamaria Camus Alessandro Facchinetti Nazario Marsich Anna Maria Manotti Lanfredi Franco Ugozzoli 《Inorganica chimica acta》1999,290(2):2043-188
The formation of complexes between copper(II) halides and 2,2′-dipyridylamine (dipyam) has been studied systematically. Only complexes with a 1:1 and 1:2 metal-to-ligand ratio are formed. Some mixed chloro–iodide and halide–PF6 compounds have also been isolated. The X-ray diffraction structures of the [Cu(dipyam)2Br2] · 2H2O (I) and the [Cu(dipyam)2Cl]2I2 · 2CH3CN (II) complexes are reported. I is a rare example of an octahedral coordination among the copper(II) halide complexes of dipyam. The two bromo atoms, which occupy the apical positions, are H-bonded to the water molecules of crystallization. II is a dimer, where each copper forms a cationic chloro-complex of approximately trigonal bipyramidal geometry, the dimerization being due to hydrogen bonds formed by the NH group of one of the two dipyams coordinated to each metal atom with the chlorine atom of the centrosymmetric cationic complex. The iodide anions are hydrogen-bonded to the NH groups of the dipyams not involved in the dimerization. 相似文献
18.
Normen Szesni 《Inorganica chimica acta》2006,359(2):617-632
Bis(alkoxy)allenylidene complexes, [(CO)5MCCC(OR′)OR], as well as mono(alkoxy)allenylidene complexes, [(CO)5MCCC(OR′)Ph], of chromium and tungsten are accessible from propynones [HCCC(O)Ph] or propynoic acid esters [HCCC(O)OR; R = Et, (−)-menthyl, endo-bornyl] by the following reaction sequence: (a) deprotonation of the alkynes, (b) reaction with [(CO)5M-THF] (M = Cr, W), and (c) alkylation of the resulting alkynyl metallate, [(CO)5MCCC(O)R], with Meerwein salts. Vinylidene complexes, [(CO)5MCC(R′)C(O)OR], are formed as a by-product by Cβ-alkylation of the alkynyl metallate. Dimethylamine displaces one alkoxy substituent of the bis(alkoxy)allenylidene complexes to give dimethylamino(alkoxy)allenylidene complexes, [(CO)5MCCC(OR)NMe2]. The analogous reaction of dimethylamine with a mono(alkoxy)-substituted allenylidene complex affords the aminoallenylidene complex [(CO)5CrCCC(NMe2)Ph]. When the amine is used in large excess, the α,β-unsaturated aminocarbene complex [(CO)5CrC(NMe2)C(H)C(NMe2)Ph] is additionally formed by addition of the amine across the CαCβ-bond of the allenylidene ligand. The reaction of [(CO)5MCCC(OEt)2] with dimethyl ethylenediamine offers access to bis(amino)allenylidene complexes, in which Cγ is part of a five-membered heterocycle. Photolysis of bis(alkoxy)allenylidene complexes in the presence of triphenylphosphine yields tetracarbonyl- and tricarbonyl{bis(phosphine)}allenylidene complexes. Diethylaminopropyne inserts into the CβCγ bond of [(CO)5MCCC(OEt)OMethyl] to give alkenylallenylidene complexes. Subsequent acid-catalyzed intramolecular cyclization affords a pyranylidene complex. 相似文献
19.
Rhodium(III) and iridium(III) octahedral complexes of general formula [MCl3{R2PCH2C(But)NNC(But)CH2PR2}] (M = Rh, Ir; R = Ph, c-C6H11, Pri, But; not all the combinations) were prepared either from the corresponding diphosphinoazines and RhCl3 · 3H2O or by the oxidation of previously reported bridging complexes [{MCl(1,2-η:5,6-η-CHCHCH2CH2CHCHCH2CH2)}2{μ-R2PCH2C(But)NNC(But)CH2PR2}] with chlorine-containing solvents. Depending on the steric properties of the ligands, complexes with facial or meridional configuration were obtained. Crystal and molecular structures of three facial and two meridional complexes were determined by X-ray diffraction. Hemilability of ligand in the complex fac-[RhCl3{(C6H11)2PCH2C(But)NNC(But)CH2P(C6H11)2}] consisting in reversible decoordination of the phosphine donor group in the six-membered ring was observed as the first step of isomerization between fac and mer isomers. 相似文献
20.
Reactions of Cr(CO)3(η6-BT), in which the Cr is π-coordinated to the benzene ring of benzo[b]thiophene (BT), with Cp′(CO)2Re(THF), where Cp′ = η5-C5H5 or η5-C5Me5, give the products Cp′(CO)2Re(η2:η6-μ2-BT)Cr(CO)3 in which the Cr remains coordinated to the benzene ring and Re is bound to the C(2)=C(3) double bond. An X-ray diffraction study of Cp(CO)2Re(η2:η6-μ2-BT)Cr(CO)3 (3) provides details of the geometry. This structure contrasts with that of the Cp′(CO)2Re(BT) complexes that exist as mixtures of isomers in which the BT is coordinated to the Re through either the double bond (2,3-η2) or the sulfur (η1(S)). Thus, the electron-withdrawing Cr(CO)3 group in 3 stabilizes the 2,3-η2 mode of BT coordination to the Cp′(CO)2Re fragment. Implications of these results for catalytic hydrodesulfurization of BT are discussed. Crystal data for 3: triclinic, space group . 相似文献