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1.
The two cyclooctatetraene metal carbonyls that have been synthesized are the tetrahapto derivative (η4-C8H8)Fe(CO)3 and the hexahapto derivative (η6-C8H8)Cr(CO)3 using the reactions of cyclooctatetraene with Fe(CO)5 and with fac-(CH3CN)3Cr(CO)3, respectively. Related C8H8M(CO)n (M = Ti, V, Cr, Mn, Fe, Co, Ni; n = 4, 3, 2, 1) species have now been investigated by density functional theory in order to explore the scope of cyclooctatetraene metal carbonyl chemistry. In this connection, the existence of octahapto (η8-C8H8)M(CO)n species is predicted as long as the central metal M does not exceed the 18-electron configuration by receiving eight electrons from the η8-C8H8 ring. Thus the lowest energy structures (η8-C8H8)Ti(CO)n (n = 3, 2, 1), (η8-C8H8)M(CO)n (M = V, Cr; n = 2, 1), and (η8-C8H8)Mn(CO) all have octahapto η8-C8H8 rings. An exception is (η6-C8H8)Fe(CO), with a hexahapto η6-C8H8 ring and thus only a 16-electron configuration for the iron atom. Hexahapto (η6-C8H8)M(CO)n structures are predicted for the known (η6-C8H8)Cr(CO)3 as well as the unknown (η6-C8H8)Ti(CO)4, (η6-C8H8)V(CO)3, (η6-C8H8)Mn(CO)2, and (η6-C8H8)Fe(CO)2 with 18, 18, 17, 17, and 18 electron configurations, respectively, for the central metal atoms. There are two types of tetrahapto C8H8M(CO)n complexes. In the 1,2,3,4-tetrahapto (η4-C8H8)M(CO)n complexes two adjacent CC double bonds, forming a 1,3-diene unit similar to butadiene, are bonded to the metal atom. In the 1,2,5,6-tetrahapto (η2,2-C8H8)M(CO)3 derivatives two non-adjacent CC double bonds of the C8H8 ring are bonded to the metal atom. The known (η4-C8H8)Fe(CO)3 is a 1,2,3,4-tetrahapto complex. The unknown isomeric 1,2,5,6-tetrahapto complex (η2,2-C8H8)Fe(CO)3 is predicted to lie ∼15 kcal/mol above (η4-C8H8)Fe(CO)3. The related 1,2,5,6-tetrahapto complexes (η2,2-C8H8)Cr(CO)4, (η2,2-C8H8)Mn(CO)4, [(η2,2-C8H8)Mn(CO)3], (η2,2-C8H8)Co(CO)2, and (η2,2-C8H8)Ni(CO)2 are all predicted to be low-energy structures.  相似文献   

2.
Binuclear cycloheptatrienylchromium carbonyls of the type (C7H7)2Cr2(CO)n (n = 6, 5, 4, 3, 2, 1, 0) have been investigated by density functional theory. Energetically competitive structures with fully bonded heptahapto η7-C7H7 rings are not found for (C7H7)2Cr2(CO)n structures having two or more carbonyl groups. This result stands in contrast to the related (CnHn)2M2(CO)n (M = Mn, n = 6; M = Fe, n = 5; M = Co, n = 4) systems. Most of the predicted (C7H7)2Cr2(CO)n structures have bent trihapto or pentahapto C7H7 rings and CrCr distances in the range 2.4–2.5 Å suggesting formal triple bonds. In some cases rearrangement of the heptagonal C7H7 ring to a tridentate cyclopropyldivinyl or tridentate bis(carbene)alkyl ligand is observed. In addition structures with CO insertion into the C7H7–Cr bond are predicted for (C7H7)2Cr2(CO)n (n = 6, 4, 2). The global minima found for the (C7H7)2Cr2(CO)n derivatives for n = 6, 5, and 4 are (η5-C7H7)(OC)2CrCr(CO)41-C7H7), (η3-C7H7)(OC)2CrCr(CO)32,1- C7H7), and (η5-C7H7)2Cr2(CO)4, respectively. The global minima for (C7H7)2Cr2(CO)n (n = 3, 2) have rearranged C7H7 groups. Singlet and triplet structures with heptahapto η7-C7H7 rings are found for the dimetallocenes (η7-C7H7)2Cr2(CO) and (η7-C7H7)2Cr2, with the singlet structures being of much lower energies in both cases.  相似文献   

3.
The interaction between Cp(CO)2RePt(μ-CCHPh)(PPh3)2 (1) and Fe2(CO)9 afforded the new heterometallic μ3-vinylidene cluster CpReFePt(μ3-CCHPh)(CO)6(PPh3) (2). An X-ray diffraction study shows the complex 2 possesses a trimetallic Re-Fe-Pt chain core. The bond lengths are Re-Fe 2.8221(8), Fe-Pt 2.5813(8) Å; the Re?Pt distance is 3.3523(7) Å; the bond angle Re-Fe-Pt is 76.55(3)°. The μ3-CCHPh ligand is η1-bound to the Re and Pt atoms and η2-coordinated to the Fe atom. The CC bond length is 1.412(4) Å. The Pt atom is coordinated by the PPh3 and CO groups. Complex 2 is characterized by the IR and 1H, 13C and 31P NMR spectra.  相似文献   

4.
The reaction of dicarbonyl- and carbonyl(trimethylphosphine)(cyclopentadienyl)-carbyne complexes of molybdenum and tungsten η5-C5H5(CO)2−n(PMe3)nMCR (n = 0, 1; M = Mo, W; R = CH3, C6H5, C6H4CH3, C3H5) with protic nucleophiles HX (X = Cl, CF3COO, CCl3COO) leads, through a combined protonation/carbon-carbon coupling reaction, to η2-acyl complexes η5-C5H5(CO)1−nX2(PMe3)n-M(η2-COCH2R). The reaction conditions, the results of the spectroscopic measurements and the X-ray structure of η5-C5H5(CO)(Cl2)W(η2-COCH2CH3) are reported.  相似文献   

5.
The synthesis and properties of heterobimetallic Ti-M complexes of type {[[Ti](μ-η12-CCSiMe3)][M(μ-η12-CCSiMe3)(CO)4]} (M = Mo: 5, [Ti] = (η5-C5H5)2Ti; 6, [Ti] = (η5-C5H4SiMe3)2Ti; M = W: 7, [Ti] = (η5-C5H5)2Ti; 8, [Ti] = (η5-C5H4SiMe3)2Ti) and {[Ti](μ-η12-CCSiMe3)2}MO2 (M = Mo: 13, [Ti] = (η5-C5H5)2Ti; 14, [Ti] = (η5-C5H4SiMe3)2Ti). M = W: 15, [Ti] = (η5-C5H5)2Ti; 16, [Ti] = (η5-C5H4SiMe3)2Ti) are reported. Compounds 5-8 were accessible by treatment of [Ti](CCSiMe3)2 (1, [Ti] = (η5-C5H5)2Ti; 2, [Ti] = (η5-C5H4SiMe3)2Ti) with [M(CO)5(thf)] (3, M = Mo; 4, M = W) or [M(CO)4(nbd)] (9, M = Mo; 10, M = W; nbd = bicyclo[2.2.1]hepta-2,5-diene), while 13-16 could be obtained either by the subsequent reaction of 1 and 2 with [M(CO)3(MeCN)3] (11, M = Mo; 12, M = W) and oxygen, or directly by oxidation of 5-8 with air. A mechanism for the formation of 5-8 is postulated based on the in-situ generation of [Ti](CCSiMe3)((η2-CCSiMe3)M(CO)5), {[Ti](μ-η12-CCSiMe3)2}-M(CO)4, and [Ti](μ-η12-CCSiMe3)((μ-CCSiMe3)M(CO)4) as a result of the chelating effect exerted by the bis(alkynyl) titanocene fragment and the steric constraints imposed by the M(CO)4 entity.The molecular structure of 5 in the solid state were determined by single crystal X-ray diffraction analysis. In doubly alkynyl-bridged 5 the alkynides are bridging the metals Ti and Mo as a σ-donor to one metal and as a π-donor to the other with the [Ti](CCSiMe3)2Mo core being planar.  相似文献   

6.
Reaction of Os3(CO)10(NCMe)2 and 1,5-cyclooctadiene (C8H12) affords the diene complex Os3(CO)104-C8H12) (1) with the two alkene moieties coordinated to an equatorial and an axial positions of one osmium atom. Thermolysis of 1 in refluxing n-hexane results in a vinylic C-H bond activation to form (μ-H)Os3(CO)9(μ,η4-C8H11) (2) in good isolated yield. The crystal structures of 1 and 2 have been established by an X-ray diffraction study.  相似文献   

7.
Density functional theory methods (B3LYP and BP86) indicate that the preferred structures for such early transition metal derivatives are (η8-C8H8)M(η4-C8H8) (M = Ti, V, Cr) with one octahapto η8-C8H8 ring and one tetrahapto η4-C8H8 ring. In such structures only 12 of the 16 carbon atoms of the two C8H8 rings are bonded to the metal, leading to 16-, 17-, and 18-electron complexes, respectively, in accord with the experimentally known structures for the Ti and V derivatives. The preferred structures for the Mn and Fe derivatives are (η6-C8H8)M(η4-C8H8) (M = Mn, Fe) with one hexahapto and one tetrahapto C8H8 ring and thus having 17- and 18-electron configurations, respectively, in accord with experimental data on the iron complex. The lowest energy structure for the cobalt complex is (η4-C8H8)Co(η2,2-C8H8) with two different types of tetrahapto C8H8 rings and a 17-electron metal configuration. The nickel complex (C8H8)2Ni appears to prefer a structure with a 16-electron configuration and two trihapto C8H8 rings, similar to the known (η3-C3H5)2Ni rather than a bis(tetrahapto) structure with the favored 18-electron configuration. These theoretical studies indicate that in (C8H8)2M derivatives of the first row transition metals, the number of carbon atoms in the pair of C8H8 rings involved in the bonding to the central metal atom gives the metal atoms 16-, 17-, or 18-electron configurations.  相似文献   

8.
The electron-rich aminorhenium complexes η51-C5H4CH2CH2NR(CH3)Re(CO)2 (3a-d; R=methyl, benzyl, n-butyl, n-butyl-OH) are easily oxidized with peroxy-acids to give the corresponding η2-CO2 complexes η5: η1- C5H4CH2CH2NR(CH3)Re(CO)(η2-CO2) (4a-d) in excellent yield. The resultant η2-CO2 complex is predominantly the anti-isomer. The structures of η2-CO2 complex η51-C5H4CH2CH2N(CH3)(n- C4H8OH)Re(CO)(η2-CO2) (4d-anti) and the corresponding CO complex 3d have been confirmed by X-ray crystallography. The η2-CO2 complexes 4a-4d are stable at ambient temperature under air. In addition to peroxy-acid oxidation, bromination of the aminorhenium dicarbonyl complexes followed by base treatment also provided the corresponding η2-CO2 complexes. The reaction mechanism for the formation of CO2 complex from the corresponding dicarbonyl is discussed briefly.  相似文献   

9.
The synthesis and characterization of two new heterotetrametallic complexes are described. Reaction of [Cr(CO)36-C6H5)CC-{(η5-C5H4)Fe(η5-C5H5)}](1) with Co2(CO)8 or Cp2Mo2(CO)4 afford the heterotetrametallic complexes [Cr(CO)36-C6H5){Co2(CO)622-CC–}(η5-C5H4)Fe(η5-C5H5)}](2), and [Cr(CO)36-C6H5){Mo2Cp2(CO)422-CC–}(η5-C5H4)Fe(η5-C5H5)](3) in 80% and 41% yield, respectively. All complexes have been characterized by elemental analysis, multinuclear (1H, 13C) NMR, and by single-crystal X-ray diffraction studies for 1 and 3. Structural data reveal that the coordination of dimolybdenum moiety to the alkyne unit influence the orientation of the carbonyl groups coordinated to the chromium as well as the Cp rings bound to the iron metal centre.  相似文献   

10.
The alkyl-bridged iron(II) complexes [{Cp(CO)2Fe}2{μ-(CnH2n)}] (n = 6-10, Cp = η5-C5H5) undergo both single and double hydride abstraction when reacted with one equivalent of Ph3CPF6 to give both the monocationic complexes, [{Cp(CO)2Fe}2{μ-(CnH2n−1)}]PF6, and the dicationic complexes, [{Cp(CO)2Fe}2{μ-(CnH2n−2)}](PF6)2. The ratios of monocationic to dicationic complexes decrease with the increase in the value of n. The complexes where n = 4 and 5 undergo only single hydride abstraction under similar conditions. When reacted with two equivalents of Ph3CPF6, the complexes where n = 6-10 undergo double hydride abstraction to give dicationic complexes only. In contrast, the complex where n = 5 gives equal amounts of the monocationic and the dicationic complexes, while the complex where n = 4 only gives the monocationic complex. 1H and 13C NMR data show that in the monocationic complexes one metal is σ-bonded to the carbenium ion moiety while the other is bonded in a η2-fashion forming a chiral metallacylopropane type structure. In the dicationic complexes both metals are bonded in the η2-fashion. The monocationic complexes where n = 4-6, react with methanol to give η1-alkenyl complexes[Cp(CO)2Fe(CH2)nCHCH2] (n = 2-4) as the major products and σ-bonded ether products [{Cp(CO)2Fe}2{μ-(CH2)nCH(OCH3)CH2}] as the minor products. The complex where n = 8 reacted with iso-propanol to give the η1-alkenyl complex [Cp(CO)2Fe(CH2)6CHCH2]. The dicationic complexes where n = 5, 8 and 9 were reacted with NaI to give the respective α, ω-dienes and [Cp(CO)2FeI].  相似文献   

11.
The thermolysis of [(C5H4)SiMe2(N-t-Bu)]TiPh2 in the presence of diphenylacetylene proceeds at 80 °C in cyclohexane solution with the sole formation of the titanacyclic complex [(C5H4)SiMe2(N-t-Bu)]Ti[(o-C6H4)C(Ph)C(Ph)], which has been characterized by solution NMR measurements and X-ray crystallographic analysis. This reaction is accompanied by the elimination of benzene and presumably occurs via coupling of a titanium benzyne intermediate with diphenylacetylene. The two chemically inequivalent Ti-C bonds of 2.081(7) and 2.103(6) Å in [(C5H4)SiMe2(N-t-Bu)]Ti[(o-C6H4)C(Ph)C(Ph)] reflect the increased electrophilicity of the d0 Ti(IV) center arising from the presence of the bifunctional ansa-cyclopentadienyldimethylsilylamido ligand.  相似文献   

12.
The complex trans-[RuPy4(CN)2] cleaves chloride bridges in the binuclear rhodium(i) and palladium(ii) complexes [Rh(CO)2Cl]2, [Rh(η4-C8H12)Cl]2, [(η4-C8H12)Rh(μ-Cl)2Rh(CO)2], [Pd(η3-C3H5)Cl]2, and [(η3-C3H5)Pd(μ-Cl)2Rh(CO)2] to form heterometallic triad complexes [(CO)2ClRh(NC)RuPy4(CN)RhCl(CO)2] (1), [(η4-C8H12)ClRh(NC)RuPy4(CN)RhCl-(η4-C8H12)] (2), [(CO)2ClRh(NC)RuPy4(CN)RhCl(η4-C8H12)] (3), [(η3-C3H5)ClPd(NC)-Ru(Py)4(CN)PdCl(η3-C3H5)] (4), and [(CO)2ClRh(NC)Ru(Py)4(CN)PdCl(η3-C3H5)] (5), respectively. In solutions, complex 3 coexists with equilibrium amounts of compounds 1 and 2; complex 5 is in the equilibrium with compounds 4 and 1. In both cases, the ratio of concentrations is close to binomial. Complexes 2 and 5 treated with [Rh(CO)2Cl]2 are converted into 1 with the simultaneous formation of [Rh(η4-C8H12)Cl]2 and [Pd(η3-C3H5)Cl]2, respectively. The δH and δC values for the ligands η4-C8H12, η3-C3H5, and CO are sensitive to the nature of the remote triad unit. The ligand effects are shown to be transmitted along the chain L′-M′-(NC)-Ru-(CN)-M″-L″.  相似文献   

13.
The Chemistry of Metal Carbonyls and Cyano Complexes in Liquid Ammonia. XXXII. On the Reaction of η5-C5H5Mo(CO)3CH3 and η5-C5H5Fe(CO)2CH3 with Liquid Ammonia η5-C5H5Mo(CO)3CH3 reacts with liquid NH3 to give η5-C5H5Mo(CO)2(NH3)H and acetamide: In contrast, η5-C5H5Fe(CO)2CH3 undergoes a carbonyl insertion to give the acetyl complex η5-C5H5Fe(CO)(NH3)COCH3: The NH3 ligand in η5-C5H5Fe(CO)(NH3)COCH3 can be substituted by pyridine.  相似文献   

14.
The nickel (0) compound Ni(COD)(GaAr′)2 (Ar′ = C6H3-2,6-(C6H3-2,6-i-Pr2)2), 1, was synthesized by the reaction of Ni(COD)2 (COD = 1,5-cyclooctadiene) with (GaAr′)2. Compound 1 reacted with ethylene at 25 °C and at 1 atm pressure to give the bimetallic cluster [Ni2(GaAr′)2112-C2H4)], 2, through the incorporation of one molecule of ethylene and displacement of COD. The structure of 2 featured an unusual Ni2Ga2C2 core bicyclic structure in which the C2H4 moiety bridges the Ga···Ga edge of a Ga2Ni2 tetrahedron. The galliums each carry an η1-bonded Ar′ substituent which complexes the nickel atom by an η6-π interaction with one of its flanking Ar’ rings.  相似文献   

15.
The acid-mediated reaction of [{Co2(CO)6(μ-η2-HOCH2CC-)}2] (1) with the meta- and para-substituted aminothiophenols, 3-NH2-C6H4SH and 4-NH2-C6H4SH, affords the straight chain species, [{Co2(CO)6(μ-η2-(3-NH2-C6H4S)CH2CC-)}2] (2) and [{Co2(CO)6(μ-η2-(4-NH2-C6H4S)CH2CC-)}2] (3), respectively. The molecular structure of 3 reveals the presence of two isomeric forms differing in the relative disposition of the S-aryl groups. Conversely, reaction of 1 with the ortho-substituted aminothiophenol, 2-NH2-C6H4SH, furnishes the 10-membered macrocyclic species [{Co2(CO)6}2{cyclo-μ-η2:μ-η2-CH2C2C2CH2SC6H3-NH-2}] (4) along with the linear chain complex [{Co2(CO)6(μ-η2-(2-NH2-C6H4S)CH2CC-)}2] (5). On the other hand, treatment of 1 with the ortho-substituted mercaptopyridine, 2-SH-C5H4N, in the presence of HBF4 gives the salt [{Co2(CO)6(μ-η2-(2-S-C5H4NH)CH2CC-)}2](BF4)2 (6a) in good yield; work-up in the presence of base affords the neutral complex [{Co2(CO)6(μ-η2-(2-S-C5H4N)CH2CC-)}2] (6b). Single crystal X-ray diffraction studies have been reported on 3-5 and 6a.  相似文献   

16.
The reaction between 1-pyrenecarboxaldehyde (C16H9CHO) and the labile triosmium cluster [Os3(CO)10(CH3CN)2] gives rise to the formation of two new compounds by competitive oxidative addition between the aldehydic group and an arene C-H bond, to afford the acyl complex [Os3(CO)10(μ-H)(μ-COC16H9)] (1) and the compound [Os3(CO)10(μ-H) (C16H8CHO)] (2), respectively. Thermolysis of [Os3(CO)10(μ-H)(μ-C16H9CO)] (1) in n-octane affords two new complexes in good yields, [Os3(CO)9(μ-H)2(μ-COC16H8)] (3) and the pyryne complex [Os3(CO)9(μ-H)23112-C16H8)] (4).In contrast, when 1-pyrenecarboxaldehyde reacts with [Ru3(CO)12] only one product is obtained, [Ru3(CO)9(μ-H)23112-C16H8)] (5), a nonacarbonyl cluster bearing a pyrene ligand. All compounds were characterized by analytical and spectroscopic data, and crystal structures for 1, 2, 4 and 5 were obtained.  相似文献   

17.
η5-C5H5(CO)2FeNa reacts with the benzimide chlorides C6H5(Cl)CNR (R  CH(CH3)2, C6H5) in boiling THF to give the η1-iminoacyl complexes η5-C5H5 (CO)2Fe[η1-C(C6H5)NR]. Alternatively, the new Fe complexes [η5-C5H5(CO)FeC(C6H5)N(CH3)C(C6H5)NCH3PF6 (IV) and [η5-C5H5(CO)2FeC(C6H5)N(CH3)C(C6H5)NCH3]PF6 (V) are formed under the same conditions, if R  CH3. Hudrolysis of the CN single bond of the ligand in V, not stabilized by a chelate effects as in IV, results in the formation of [η5-C5H5(CO)2FeC(C6H5)NHCH3]PF6 (VII). Reaction of η5-C5H5(CO)2 with N-benyzylbenzimido chloride yields η5-C5H5(CO)2FeCH2C6H5 as the only isolated product.  相似文献   

18.
Reaction of Mo(CO)3(NCMe)3 and PPh2(o-C6H4)C(O)H (abbreviated as PCHO) at room temperature affords Mo(CO)2(η3-PCHO)2 (1), while compound 1 and the phosphine-imine complex Mo(CO)4(η2-PPh2(o-C6H4)CHNMe) (2) are obtained by using Mo(CO)3(η3-(MeNCH2)3) as the reactant. Thermal reaction of 1 with C60 products Mo(CO)2(η4-(PPh2(o-C6H4)CH)2)(η2-C60) (3) in low yield, apparently through coupling of the formyl moieties. The structures of 1 and 3 have been determined by an X-ray diffraction study. The two aldehyde groups of 1 and C60 ligand of 3 are coordinated to the molybdenum atom in a π-fashion.  相似文献   

19.
《Polyhedron》2007,26(5):981-988
New π-conjugated butadiynyl ligand FcC(CH3)2Fc′–CC–CC–Ph (L1) has been synthesized and its reaction with Co2(CO)8 has been studied. New clusters [FcC(CH3)2Fc′–CC–CC–Ph][Co2(CO)6]n [(1): n = 1; (2): n = 2] and [Fc–CC–CC–Ph][Co2(CO)6]n [(3): n =  1; (4): n = 2] were obtained by the reaction of ligands FcC(CH3)2Fc′–CC–CC–Ph (L1) and Fc–CC–CC–Ph (L2) with Co2(CO)8 respectively and the composition and structure of the clusters and ligands have been characterized by elemental analysis, FTIR, 1H and 13C NMR and MS. The crystal structures of compounds L1, L2, 2 and 4 have been determined by X-ray single crystal analysis.  相似文献   

20.
Treatment of [RuCl26-C6H6)]x with bidentate phosphine ligand BDNA [1,8-bis(diphenylphosphinomethyl)naphthalene] in methanol at room temperature gave η6-benzene-ruthenium complexes Ru2Cl46-C6H6)2(μ-BDNA) (1). Complex 1 further reacted with AgBF4 to form complex [Ru2Cl2(μ-Cl)(η6-C6H6)2(μ-BDNA)](BF4) (2). [RuCl26-C6H6)]x reacted with BDNA in refluxing methanol and then the reaction solution was treated with AgBF4 to generate complex [Ru2Cl26-C6H6)2(μ-BDNA)2](BF4)2 (3). Their compositions and structures had been determined by elemental analyses, NMR spectra and single crystal X-ray diffractions. X-ray diffraction showed that complex 1 belonged to monoclinic crystal system, P21/c space group with Z = 4, a = 12.810 Å, b = 21.507 Å, c = 18.471 Å, β = 107.95°; complex 2 belonged monoclinic crystal system, P21/n space group with Z = 4, a = 14.498 Å, b = 15.644 Å, c = 20.788 Å, β = 103.404°, and complex 3 belonged to monoclinic crystal system, P21/n space group with Z = 2, a = 13.732 Å, b = 14.351 Å, c = 19.733 Å, β = 94.82°.  相似文献   

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