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1.
The reaction of norbornene (NBE) and norbornadiene (NBD) in the presence of seven-coordinate tungsten(II) and molybdenum(II) complexes of the [(CO)4M(μ-Cl)3M(SnCl3)(CO)3] and [MCl(M′Cl3)(CO)3(NCMe)2] (M=W, Mo; M′=Sn, Ge) types leads to ring-opening metathesis polymerization (ROMP) and to the formation of high molecular weight polymers. The geometric structure of these polymers was determined by means of 1H- and 13C-NMR spectroscopy. The monitoring of the reaction between cyclic olefins and the metal complex by means of 1H-NMR spectroscopy allowed us to observe the coordination of NBD to metal atoms in the initiation step of the polymerization process. Compounds of the [MCl(SnCl3)(CO)34-NBD)] type prepared directly from [(CO)4M(μ-Cl)3M(SnCl3)(CO)3] or [MCl(M′Cl3)(CO)3(NCMe)2] (M=W, Mo) in the presence of an excess of NBD initiate the ROMP reaction immediately. The detection of the first-formed products in the reaction between the metal complex and cyclic olefins provides valuable information concerning the nature of the initiating species.  相似文献   

2.
The product isolated from the reaction of (μ-H)2Os3(CO)9(PPh3) with ethylene is shown to be the ethylidene complex (μ-H)2Os3(CO)9(PPh3)(μ-CHCH3) (1) rather than the ethylene complex (μ-H)(H)Os3(CO)9(PPh3)(C2H4), as previously claimed. The characterization of 1 is based on a combination of 1H and 13C NMR results. The 1H NMR data (δ 6.84 (1 HD), 2.53 (3 HC), J(CD) = 7.4 Hz) establish the presence of the ethylidene moiety, whereas detailed analysis of the 1-D and 2-D 13C NMR spectra of 13CO-enriched 1 indicates the relative positions of the ethylidene, hydride, and phosphine ligands on the triosmium framework.  相似文献   

3.
The compound [RU332- -ampy)(μ3η12-PhC=CHPh)(CO)6(PPh3)2] (1) (ampy = 2-amino-6-methylpyridinate) has been prepared by reaction of [RU3(η-H)(μ32- ampy) (μ,η12-PhC=CHPh)(CO)7(PPh3)] with triphenylphosphine at room temperature. However, the reaction of [RU3(μ-H)(μ3, η2 -ampy)(CO)7(PPh3)2] with diphenylacetylene requires a higher temperature (110°C) and does not give complex 1 but the phenyl derivative [RU332-ampy)(μ,η 12 -PhC=CHPh)(μ,-PPh2)(Ph)(CO)5(PPh3)] (2). The thermolysis of complex 1 (110°C) also gives complex 2 quantitatively. Both 1 and 2 have been characterized by0 X-ray diffraction methods. Complex 1 is a catalyst precursor for the homogeneous hydrogenation of diphenylacetylene to a mixture of cis- and trans -stilbene under mild conditions (80°C, 1 atm. of H2), although progressive deactivation of the catalytic species is observed. The dihydride [RU3(μ-H)232-ampy)(μ,η12- PhC=CHPh)(CO)5(PPh3)2] (3), which has been characterized spectroscopically, is an intermediate in the catalytic hydrogenation reaction.  相似文献   

4.
The singlet-triplet separations for the edge-sharing bioctahedral (ESBO) complex W2(μ-H)(μ-Cl)(Cl4(μ-dppm)2 · (THF)3 (II) has been studied by 31P NMR spectroscopy. The structural characterization of [W2(μ-H)2(μ-O2CC6H5)2Cl2(P(C6H5)3)2] (I) by single-crystal X-ray crystallography has allowed the comparison of the energy of the HOMOLUMO separation determined using the Fenske-Hall method for a series of ESBO complexes with two hydride bridging atoms, two chloride bridging atoms and the mixed case with a chloride and hydride bridging atom. The complex representing the mixed case, [W2(μ-H)(μ-Cl)Cl4(μ-dppm)2 · (THF)3] (II), has been synthesized and the value of −2J determined from variable-temperature 31P NMR spectroscopy.  相似文献   

5.
Reaction of the activated mixture of Re2(CO)10, Me3NO and MeOH with a 1:1 mixture of rac (d/l)- and meso-1,1,4,7,10,10-hexaphenyl-1,4,7,10-tetraphosphadecane (hptpd) yields a mixture of (d/l)- and meso-[{Re2(μ-OMe)2(CO)6}2(μ,μ′-hptpd)] 1. The diastereomers can be easily separated by selective dissolution of d/l-1 in benzene, and give clearly distinguishable 1H- and 31P-NMR spectra. The fluxional behavior of d/l-1 in solution has been studied by variable-temperature 1H- and 31P-{1H}-NMR spectroscopy. The crystal structures of both d/l- and meso-1 have been determined. Both molecules consist of two {Re2(μ-OMe)2(CO)6} moieties which are bridged by the two P---CH2---CH2---P moieties of the hptpd ligand. Whilst the molecules of meso-1 possess crystallographic i-symmetry, those of d/l-1 do not have any crystallographic symmetry. These diastereomers therefore give clearly distinguishable Raman spectra in the solid state. Reaction of tris[2-(diphenylphosphino)ethyl]phosphine (tdppep) with the activated mixture affords the complex [{Re2(μ-OMe)2(CO)6}(μ,η2-tdppep)] 2, and the analogous reaction involving bis[2-diphenylphospinoethyl)phenylphosphine (triphos) gives [{Re2(μ-OMe)2(CO)6}(μ,μ′,η3-triphos){Re2(CO)9}] 3 and [{Re2(μ-OMe)2(CO)6}(μ,η2-triphos)] 4.  相似文献   

6.
The reactions of the half-sandwich molybdenum(III) complexes CpMo(η4-C4H4R2)(CH3)2, where Cp=η5-C5H5 and R=H or CH3, with equimolar amounts of B(C6F5)3 have been investigated in toluene. EPR monitoring shows the formation of an addition product which does not readily react with Lewis bases such as ethylene, pyridine, or PMe3. The analysis of the EPR properties and the X-ray structure of a decomposition product obtained from dichloromethane, [CpMo(η4-C4H6)(μ-Cl)(μ-CH2)(O)MoCp][CH3B(C6F5)3], indicate that the borane attack has occurred at the methyl position.  相似文献   

7.
8.
The cationic diphenylphosphido-bridged compound [Ru2(μ-PPh2)(μ-OH)26-p-cymene)2][PF6) (2) has been prepared by reaction of the tri-μ-hydroxo complex [Ru2(μ-OH)3(η-p-cymene)2][PF6] (1) with diphenylphosphine. Complex 2 eliminates water on reaction with protic acids, incorporating the conjugate base of the added acid as a bridging ligand. Formic acid, acetic acid, phenol, and aniline react with 2 to give the monosubstituted compounds [Ru2(μ-PPh2)(μ-OH)(μ-L)(η6-p-cymene)2]PF6] (L = HCO2, MeCO2, OPh, or NHPH), whereas methanol, thiophenol, 1,2-benzenedithiol, hydrochloric acid and isopropanol afford the disubstituted derivatives [Ru2(μ-PPh2)(μ-L)26-p-cymene)2]PF6] (L = OMe, SPh, S2C6H4, Cl, or H).  相似文献   

9.
Synthesis of H3Ru33-CSEt)(CO)9, is accomplished by base-promoted attack of ethanethiol on H3Ru33-CBr)(CO)9. Thermolysis of this product under CO yields HRu3(CH2SEt)(CO)9. Reactions of H3Ru33-CSEt)(CO)9 with alkynes C2R2 form HRu333-EtSCCRCR)(CO)9 (R = Me or Ph) and Ru3 (cis-CR=CHR)(CSEt)(CO)9 (R = Me). The chemistry of H3Ru33-CSEt)(CO)9 differs significantly from that of the analogous ether derivative H3Ru33-COMe)(CO)9.  相似文献   

10.
The reaction of bis(pyrazol-1-yl)methane tetracarbonylmolybdenum(0) or tungsten(0) complexes with RSnCl3 (R=Ph, Cl) at room temperature yielded heterobimetallic complexes CH2(Pz)2M(CO)3(Cl)(SnCl2R) (Pz represents substituted pyrazole; M=Mo or W; R=Ph or Cl) in good yields, which have been characterized by elemental analysis, 1H NMR and IR spectroscopy. The reaction of bis(3,5-dimethyl-4-halopyrazol-1-yl)methane tetracarbonyl tungsten with PhSnCl3 did not take place even in refluxing CH2Cl2. The electronic and steric characteristics of substituents on the pyrazole ring remarkably influence the structures of the products. The structures of CH2(3,5-Me2-4-BrPz)2W(CO)3(Cl)(SnCl3) (8) and CH2(4-BrPz)2Mo(CO)3(μ-Cl)(SnCl2Ph) (17) (Pz: pyrazole) determined by X-ray crystallography show that no chlorine-bridged W---Sn bond is observed in complex 8, while one chlorine-bridged Mo---Sn bond exists in complex 17. The Sn---M bond length is 2.7438(5) Å in complex 8 (W---Sn) and 2.7559(4) Å in complex 17 (Mo---Sn).  相似文献   

11.
The reaction of [(CO)PPh3)2Re(μ-H)2(μ-NCHPh)Ru(PPh3)2(PhCN)] (2) with HBF4-Me2O generates [(CO)PPh3)2Re(μ- H)2(μ,η12HNCHPh)Ru(PPh3)2(PhCN)][BF4] (3). Monitoring the reaction by NMR spectroscopy shows the intermediate formation of [(CO)(PPh3)2 HRe(μ-H)2(μ-NCHPh)Ru(PPh3)2(PhCN)][BF4] (4). Attempted reduction of the imine ligand by a nucleophile (H or CN) failed, regenerating 2. Under dihydrogen at 50 atm, 3 is slowly transformed into [(CO)(PPh3)2HRe(μ-H)3Ru(PPh3)2(PhCN)][BF4] (5) with liberation of benzyl amine.  相似文献   

12.
The reaction between Ru3(CO)12 and a cyclic olefin (cis-cyclooctene or trans-cyclododecene) at 100 °C for several hours gives the title compounds (μ-H)2RU3(CO)932-C8H12) (1), and (μ-H)RU3(CO)933-C12H19) (2), both of which have been characterized by X-ray diffraction studies, IR and NMR spectral measurements and elemental analysis. The prolonged reaction between Ru3(CO)12 and cis-cyclooctene gives compound HRu3(CO)9(C8H11) (3). Compound 3 has been characterized with IR and NMR spectral analyses. In 1 the cyclooctene ring is linked via a μ32-alkyne type of bonding to the face of the Ru3 cluster. It is formally σ-bonded to two of the three Ru atoms and π-bonded to the third Ru. The two hydrides in 1 are bridging Ru---Ru bonds. In 2 the cyclododecene ring is bonded to the Ru3 face via the μ33-CCHC linkage. There are two formal σ-bonds from the allyl part to the hydrido-bridged Ru atoms and the η3-allyl linkage to the third Ru atom.  相似文献   

13.
The reactions of the diruthenium carbonyl complexes [Ru2(μ-dppm)2(CO)4(μ,η2-O2CMe)]X (X=BF4 (1a) or PF6 (1b)) with neutral or anionic bidentate ligands (L,L) afford a series of the diruthenium bridging carbonyl complexes [Ru2(μ-dppm)2(μ-CO)22-(L,L))2]Xn ((L,L)=acetate (O2CMe), 2,2′-bipyridine (bpy), acetylacetonate (acac), 8-quinolinolate (quin); n=0, 1, 2). Apparently with coordination of the bidentate ligands, the bound acetate ligand of [Ru2(μ-dppm)2(CO)4(μ,η2-O2CMe)]+ either migrates within the same complex or into a different one, or is simply replaced. The reaction of [Ru2(μ-dppm)2(CO)4(μ,η2-O2CMe)]+ (1) with 2,2′-bipyridine produces [Ru2(μ-dppm)2(μ-CO)22-O2CMe)2] (2), [Ru2(μ-dppm)2(μ-CO)22-O2CMe)(η2-bpy)]+ (3), and [Ru2(μ-dppm)2(μ-CO)22-bpy)2]2+ (4). Alternatively compound 2 can be prepared from the reaction of 1a with MeCO2H–Et3N, while compound 4 can be obtained from the reaction of 3 with bpy. The reaction of 1b with acetylacetone–Et3N produces [Ru2(μ-dppm)2(μ-CO)22-O2CMe)(η2-acac)] (5) and [Ru2(μ-dppm)2(μ-CO)22-acac)2] (6). Compound 2 can also react with acetylacetone–Et3N to produce 6. Surprisingly [Ru2(μ-dppm)2(μ-CO)22-quin)2] (7) was obtained stereospecifically as the only one product from the reaction of 1b with 8-quinolinol–Et3N. The structure of 7 has been established by X-ray crystallography and found to adopt a cis geometry. Further, the stereospecific reaction is probably caused by the second-sphere π–π face-to-face stacking interactions between the phenyl rings of dppm and the electron-deficient six-membered ring moiety of the bound quinolinate (i.e. the N-included six-membered ring) in 7. The presence of such interactions is indeed supported by an observed charge-transfer band in a UV–vis spectrum.  相似文献   

14.
The methylene-bridged, mixed-chalogen compounds Fe2(CO)6(μ-SeCH2Te) (1) and Fe2(CO)6(μ-SCH2Te) (3) have been synthesised from the room temperature reaction of diazomethane with Fe2(CO)6(μ-SeTe) and Fe2(CO)6(μ-STe), respectively. Compounds 1 and 3 have been characterised by IR, 1H, 13C, 77Se and 125Te NMR spectroscopy. The structure of 1 has been elucidated by X-ray crystallography. The crystalsare monoclinic,space group P21/n, A = 6.695(2), B = 13.993(5), C = 14.007(4)Å, β = 103.03(2)°, V = 1278(7) Å3, Z = 4, Dc = 2.599 g cm−3 and R = 0.030 (Rw = 0.047).  相似文献   

15.
The complex [MoW(μ-CC6H4Me-4)(CO)27-C7H7)(η5-C2B9H10Me)] reacts with diazomethane in Et2O containing EtOH to afford the dimetal compound [MoW(OEt)(μ-CH2){μ-C(C6H4Me-4)C(Me)O}(η7-C7H7)(η5-C2B9H10Me)]. The structure of this product was established by X-ray diffraction. The Mo---W bond [2.778(4) Å] is bridged by a CH2 group [μ-C---Mo 2.14(3), μ-C---W 2.02(3) Å] and by a C(C6H4Me-4)C(Me)O fragment [Mo---O 2.11(3), W---O 2.18(2), Mo---C(C6H4Me-4) 2.41(3), W---C(C6H4Me-4) 2.09(3), Mo---C(Me) 2.26(3) Å]. The molybdenum atom is η7-coordinated by the C7H7 ring and the tungsten atom is η5-coordinated by the open pentagonal face of the nido-icosahedral C2B9H10Me cage. The tungsten atom also carries a terminally bound OEt group [W---O 1.88(3) Å]. The 1H and 13C-{1H} NMR data for the dimetal compound are reported and discussed.  相似文献   

16.
The title complex Mn2(CO)6(μ-H){μ-S(SC3H5)C=C(PPr3i)S} was synthesized by allyation of the homobinuclear anion [Mn2(CO)6(μ-H){μ-S(SC3H5)C=C(PPr3i)S}]−1, and characterized by elemental analysis, IR, 1H NMR and 31P NMR spectra. The molecular structure shows that it contains a novel fairly planar ligand S(S)C=C(PPr3i)S, and the two Mn(CO)3 fragments are symmetrically placed at both sides of the plane of the ligand.  相似文献   

17.
The coordinatively unsaturated cluster [Pt33-CO)(μ-dppm)3]2+ (1, dppm = Ph2PCH2PPh2) reacts with Na+[M(CO)5] to give the mixed metal clusters [Pt3{M(CO)3}(μ-dppm)3]+ (M = Re, 2; Mn, 3). The new clusters are characterized by spectroscopic methods and, for M = Re, by an X-ray structure determination. The Pt3Re core in 2 is tetrahedral with particularly short metal-metal distances.  相似文献   

18.
The reaction of the anionic mononuclear rhodium complex [Rh(C6F5)3Cl(Hpz)]t- (Hpz = pyrazole, C3H4N2) with methoxo or acetylacetonate complexes of Rh or Ir led to the heterodinuclear anionic compounds [(C6F5)3Rh(μ-Cl)(μ-pz)M(L2)] [M = Rh, L2 = cyclo-octa-1,5-diene, COD (1), tetrafluorobenzobarrelene, TFB (2) or (CO)2 (4); M = Ir, L2 = COD (3)]. The complex [Rh(C6F5)3(Hbim)] (5) has been prepared by treating [Rh(C6F5)3(acac)] with H2bim (acac = acetylacetonate; H2bim = 2,2′-biimidazole). Complex 5 also reacts with Rh or Ir methoxo, or with Pd acetylacetonate, complexes affording the heterodinuclear complexes [(C6F5)3Rh(μ-bim)M(L2)] [M = Rh, L2 = COD (6) or TFB (7); M = Ir, L2 = COD (8); M = Pd, L2 = η3-C3H5 (9)]. With [Rh(acac)(CO)2], complex 5 yields the tetranuclear complex [{(C6F5)3Rh(μ-bim)Rh(CO)2}2]2−. Homodinuclear RhIII derivatives [{Rh(C6F5)3}2(μ-L)2]·- [L2 = OH, pz (11); OH, StBu (12); OH, SPh (13); bim (14)] have been obtained by substitution of one or both hydroxo groups of the dianion [{Rh(C6F5)3(μ-OH)}2]2− by the corresponding ligands. The reaction of [Rh(C6F5)3(Et2O)x] with [PdX2(COD)] produces neutral heterodinuclear compounds [(C6F5)3Rh(μ-X)2Pd(COD)] [X = Cl (15); Br (16)]. The anionic complexes 1–14 have been isolated as the benzyltriphenylphosphonium (PBzPh3+) salts.  相似文献   

19.
A high yield synthesis of the carbonyl dithiocarbamato derivative Fe(CO)22-S2CNMe2)2 and Fe(η2-S2CNMe2)2 by photolysis with visible light of solutions containing Fe2(CO)9 or Fe3(CO)12 and [(η5-C5H5)(CO)3W(η1-SCSNMe2)] is reported.  相似文献   

20.
Structures of non metal-metal bonded phosphido-bridged heterobimetallic complexes, including CpFe(CO)2(μ-PPh2)W(CO)5 (1-W) and metal-metal bonded CpFe(CO)(μ-CO)(μ-PPh2)W(CO)4 (2), were determined by a single crystal X-ray diffraction study. In 1-W, the long distance between Fe and W indicates no metal-metal bond to exist. In 2, a Fe---W bond with bond length 2.851 Å and a semibridging carbonyl with W---C---O angle 153° were observed. Mössbauer spectra of 1-W and 2 were taken at 77 K. Isomer shifts of 1-W and 2 were − 0.0203 mm s−1 and 0. 1917 mm s−1 respectively.  相似文献   

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