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1.
Photolysis of cis-Fe(CO)4X2, where X = Br and I, results in low energy, facile rearrangement to the trans isomer with no evidence of CO-loss. In contrast, the isoelectronic cis-Mn(CO)4Br2 anion exhibits CO-loss upon photolysis with only weak evidence for the trans isomer. The photolysis of Mn(CO)5Br, Mn(CO)4Br(PBu3) and Mn(CO)3Br(PBu3)2 have also been examined in frozen matrices.  相似文献   

2.
The reaction of [HRe3(CO)12]2− with an excess of Ph3PAuCl in CH2Cl2 yields [(Ph3PAu)4Re(CO)4]+ as the main product, which crystallizes as [(Ph3PAu)4Re(CO)4]PF6 · CH2Cl2 (1 · CH2Cl2) after the addition of KPF6.The crystal structure determination reveals a trigonal bipyramidal Au4Re cluster with the Re atom in equatorial position.If [(Ph3PAu)4Re(CO)4]+ is reacted with PPh4Cl, a cation [Ph3PAu]+ is eliminated as Ph3PAuCl, and the neutral cluster [(Ph3PAu)3Re(CO)4] (2) is formed.It combines with excess [(Ph3PAu)4Re(CO)4]+ to afford the cluster cation, [(Ph3PAu)6AuRe2(CO)8]+. It crystallizes from CH2Cl2 as[(Ph3PAu)6AuRe2(CO)8]PF6 · 4CH2Cl2 (3 · 4CH2Cl2). In [(Ph3PAu)3Re(CO)4] the metal atoms are arranged in form of a lozenge while in [(Ph3PAu)6AuRe2(CO)8]+ two Au4Re trigonal bipyramids are connected by a common axial Au atom.The treatment of [(Ph3PAu)4Re(CO)4]+ with KOH and Ph3PAuCl in methanol yields the cluster cation [(Ph3PAu)6Re(CO)3]+, which crystallizes with from CH2Cl2 as [(Ph3PAu)6Re(CO)3]PF6 · CH2Cl2 (4 · CH2Cl2). The metal atoms in this cluster form a pentagonal bipyramid with the Re atom in the axial position.  相似文献   

3.
(C5H5)W(CO)3Cl has been prepared in >90% yield from W(CO)6, cyclopentadiene, and CCl4 in a single-flask synthesis involving the intermediates W(CO)3(CH3CN)3 and (C5H5)W(CO)3H.  相似文献   

4.
The reactions of the butterfly complex Ru4(CO)12(MeC2Ph) with several alkynes give the quasiplanar derivatives Ru4(CO)11(MeC2Ph)(Alkyne) in almost quantitative yields.The structure of Ru4(CO)11(MeC2Ph)2 has been determined by X-ray methods. Crystals are monoclinic, space group C2/c, with Z = 4 in a unit cell of dimensions a 22.383(16), b 9.048(8), c 18.268(12) Å, β = 127.25(4)°. The structure has been solved from diffractometer data by Patterson and Fourier methods and refined by full-matrix least-squares to R = 0.034 for 1420 observed reflections. The complex, having an imposed C2 symmetry, presents a tetranuclear metal cluster in which the Ru atoms are in a tetrahedrally-distorted square arrangement. Ten carbonyls are terminal and one symmetrically bridges an edge of the cluster. Each of the two alkyne ligands is σ-bonded to two Ru atoms on the opposite vertices of the cluster and π-bonded to the other two. The organometallic cluster has a Ru4C4 core in which the metal and carbon atoms occupy the vertices of a triangulated dodecahedron.  相似文献   

5.
The mono-substituted amine derivatives [Ir4(CO)11L] (L = pyridine (1), 4-methylpyridine (2), 4-ter-butyl pyridine (3), 3,5-dimethylpyridine (4), 3,4-dimethylpyridine (5)) were obtained by the reaction of [Ir4(CO)11Br] with the corresponding aromatic amine. In the solid state, cluster 2 has an approximate Cs symmetry with all terminal ligands as shown by an X-ray analysis. In solution, this unbridged structure is in dynamic equilibrium with two other isomeric forms having three edge-bridging CO’s on a common basal face and the amine ligand coordinated in axial or in radial position relative to this face.  相似文献   

6.
Reaction of HSi(OEt)3 with IrCl(CO)(PPh3)2 (5:1 molar ratio) at room temperature for 1 h gives IrCl(H){Si(OEt)3}(CO)(PPh3)2 (1), which is observed by the 1H and 31P{1H} NMR spectra of the reaction mixture. The same reaction, but in 20:1 molar ratio at 50 °C for 24 h produces IrCl(H)2(CO)(PPh3)2 (2) rather than the expected product Ir(H)2{Si(OEt)3}(CO)(PPh3)2 (3) that was previously reported to be formed by this reaction. Accompanying formation of Si(OEt)4, (EtO)3SiOSi(OEt)3, and (EtO)2HSiOSi(OEt)3 is observed. On the other hand, trialkylhydrosilane HSiEt3 reacts with IrCl(CO)(PPh3)2 (10:1 molar ratio) at 80 °C for 84 h to give Ir(H)2(SiEt3)(CO)(PPh3)2 (4) in a high yield, accompanying with a release of ClSiEt3.  相似文献   

7.
Reaction of Mo(CO)4(NCCH3)2 and 7-aza-2-tosylnorbornadiene (7-azaNBD) yielded five air-stable Mo complexes. One is Mo(CO)44-7-azaNBD), in which the molybdenum atom is chelated by the two π-bonds of 7-azaNBD. The other four are isomers of Mo(CO)22-7-azaNBD)2, in which the molybdenum atoms are chelated by the nitrogen atom and one of the two double bonds of 7-azaNBD. In one pair of the isomers, the metal binds to C(2)C(3) of both 7-azaNBD ligands; whereas in the other pair of isomers the metal binds to C(2)C(3) of one 7-azaNBD ligand and C(5)C(6) of another ligand. All structures were fully characterized by NMR spectra. A single crystal of compound 4 was analyzed by X-ray diffraction analysis, which was found to be monoclinic with a = 8.4199, b = 23.984, c = 16.395 Å, and β = 99.99°.  相似文献   

8.
The reactions of lithium(diphenylphosphino)tetramethylcyclopentadienide with CpTiCl3 and secondly with TiCl3 followed by CCl4 oxidation lead to the formation of two titanocene phosphines: (η5-C5H5)[η5-C5Me4P(C6H5)2]TiCl2 (2) and [η5-C5Me4P(C6H5)2]2TiCl2 (3), respectively. The metalloligand 3 reacts readily with Mo(CO)4cod, Mo(CO)5THF and Mo(CO)6 to give in each case [(η5-C5Me4 o(CO)4 (6) as a sole product. The structure of 6 has been determined by X-ray diffraction. Crystal data: P , a = 11.716(1), b = 11.753(2), c = 16.110(2) Å, α = 99.06(1), β = 92.61(1), γ = 104.20(1)°, Z = 2. The molybdenum-titanium distance of 5.194(1) Å rules out any metal-metal interaction. The chlorine substitution reactions by CO in 2 and 3 and by thiolate group (pH3C-C6H4-S) in 16 are reported.  相似文献   

9.
Mo(CO)4(LL) complexes, where LL = polypyridyl ligands such as 2,2′-bipyridine and 1,10-phenanthroline, undergo quasi-reversible, one-electron oxidations in methylene chloride yielding the corresponding radical cations, [Mo(CO)4(LL)]+. These electrogenerated species undergo rapid ligand substitution in the presence of acetonitrile, yielding [Mo(CO)3(LL)(CH3CN)]+; rate constants for these substitutions were measured using chronocoulometry and were found to be influenced by the steric and electronic properties of the polypyridyl ligands. [Mo(CO)3(LL)(CH3CN)]+ radical cations, which could also be generated by reversible oxidation of Mo(CO)3(LL)(CH3CN) in acetonitrile, can be irreversibly oxidized yielding [Mo(CO)3(LL)(CH3CN)2]2+ after coordination by an additional acetonitrile. Infrared spectroelectrochemical experiments indicate the radical cations undergo ligand-induced net disproportionations that follow first-order kinetics in acetonitrile, ultimately yielding the corresponding Mo(CO)4(LL) and [Mo(CO)2(LL)(CH3CN)3]2+ species. Rate constants for the net disproportionation of [Mo(CO)3(LL)(CH3CN)]+ and the carbonyl substitution reaction of [Mo(CO)3(LL)(CH3CN)2]2+ were measured. Thin-layer bulk oxidation studies also provided infrared characterization data of [Mo(CO)4(ncp)]+ (ncp = neocuproine), [Mo(CO)3(LL)(CH3CN)]+, [Mo(CO)3(LL)(CH3CN)2]2+ and [Mo(CO)2(LL)(CH3CN)3]2+ complexes.  相似文献   

10.
The compounds W(CO)5P(C6H4-4-CH2CH2(CF2)7CF3)3 (1) and W(CO)5P(CH2CH2(CF2)5CF3)3 (2) were synthesized in order to probe the electronic and physical effects of ligation by perfluorocarbon substituted tertiary phosphine ligands in a W(CO)5L complex. The π-accepting ability of the fluorous phosphines was found to rank with non-fluorous comparators as P(CH2CH2(CF2)5CF3)3 > P(C6H4-4-CH2CH2(CF2)7CF3)3 > PPh3 > P(p-tolyl)3 > P(n-octyl)3. The X-ray crystal structure of W(CO)5P(C6H4-4-CH2CH2(CF2)7CF3)3 shows strong intermolecular association of fluorous components but confirms that the para fluorocarbon subtituents have an insignificant effect on the tungsten coordination environment. Partition coefficients (toluene/perfluoromethylcyclohexane) were measured for compounds 1 and 2.  相似文献   

11.
The structures and relative energies of the As2Co2(CO)n (n = 6, 5, 4) derivatives are predicted by density functional theory to be analogous to those of the corresponding H2C2Co2(CO)n derivatives. Thus As2Co2(CO)6 is predicted to have three carbonyls on one cobalt atom eclipsed relative to the three carbonyls on the other cobalt atom. The corresponding As2Co2(CO)6 structure with a staggered rather than eclipsed arrangement of the Co(CO)3 units is a transition state rather than a genuine minimum. For As2Co2(CO)5 the structure in which an equatorial group is removed from the As2Co2(CO)6 structure and a singly bridged As2Co2(CO)4(μ-CO) structure are predicted to have essentially the same energies, within <2 kcal/mol. A higher energy As2Co2(CO)5 structure by 9 ± 2 kcal/mol is derived from the As2Co2(CO)6 structure by removal of an axial carbonyl group. The two unbridged As2Co2(CO)5 structures correspond to those observed experimentally in the photolysis of As2Co2(CO)6 in Nujol matrices at low temperatures. In such photolysis experiments the higher energy isomer is produced initially and then converted to the lower energy isomer upon annealing. A singly bridged structure was found for As2Co2(CO)4. The analogous structure was not observed in the previous work with H2C2Co2(CO)4. However, such a H2C2Co(CO)3(μ-CO) structure is found here for the acetylene complex. This singly bridged structure is predicted to lie 1.9 kcal/mol below the H2C2Co2(CO)44-1S structure by the BP86 method but 3.5 kcal/mol above the latter by the B3LYP method. In addition to the singly bridged As2Co2(CO)4 structure, the same six unbridged structures were located for As2Co2(CO)4 that were previously found for H2C2Co2(CO)6.  相似文献   

12.
The organotin complex [Ph3SnS(CH2)3SSnPh3] (1) was synthesized by PdCl2 catalyzed reaction between Ph3SnCl and disodium-1,3-propanedithiolate which in turn was prepared from 1,2-propanedithiol and sodium in refluxing THF. Reaction of 1 with Ru3(CO)12 in refluxing THF affords the mononuclear complex trans-[Ru(CO)4(SnPh3)2] (2) and the dinuclear complex [Ru2(CO)6(μ-κ2-SCH2CH2CH2S)] (3) in 20 and 11% yields, respectively, formed by cleavage of Sn-S bond of the ligand and Ru-Ru bonds of the cluster. Treatment of pymSSnPPh3 (pymS = pyrimidine-2-thiolate) with Ru3(CO)12 at 55-60 °C also gives 2 in 38% yield. Both 1 and 2 have been characterized by a combination of spectroscopic data and single crystal X-ray diffraction analysis.  相似文献   

13.
The character of the two lowest energy transitions of W(CO)4(bpym) and (μ-bpym)[M(CO)4]2 (M=Mo, W) were established with resonance Raman spectroscopy. According to these spectra the two bands belong to MLCT transitions to different π* orbitals of the bpym ligand. Contrary to expectations it is not the first (lowest energy) but the second and more intense electronic transition which, according to the resonance Raman spectra, is directed to the lowest lying π* orbital (b2u*, LUMO) of these complexes. This interpretation explains the different band intensities and the untypically low g values of the ESR signals of corresponding anion radicals. Excitation of (μ-bpym)[Mo(CO)4]2 in CH2Cl2 at 400 nm produced a weak emission with an onset at 700 nm. According to the excitation spectrum, this emission originates from the lowest MLCT-excited state of the complex.  相似文献   

14.
A new CoII/CoIII hexanuclear complex, [Co4IICo2III(dea)2(Hdea)4)(piv)4](ClO4)2·H2O 1, has been obtained by reacting cobalt(II) perchlorate, diethanolamine, and pivalic acid (H2dea = diethanolamine and piv = pivalato anion). The cobalt ions are held together by four μ3 and four μ2 alkoxo bridges as well as by four syn-syn carboxylato groups. The hexanuclear motif contains four Co(II) and two Co(III) ions. The {CoII4CoIII22-O)43-O)4} core can be described as a four face-sharing monovacant and bivacant distorted heterocubane units. The cobalt(III) ions are hexacoordinated. Two of the cobalt(II) are hexacoordinated, while the two others are pentacoordinated with a bipyramidal stereochemistry. The magnetic properties of 1 have been investigated in the temperature range 1.9-300 K. Compound 1 exhibits an overall antiferromagnetic behaviour with a ground singlet spin state.  相似文献   

15.
Flash photolysis with time-resolved infrared (TRIR) spectroscopy was used to elucidate the photochemical reactivity of the hydroformylation catalyst precursor Co2(CO)6(PMePh2)2. Depending on reaction conditions, the net products of photolysis varied significantly. A model is presented that accounts for the net reactivity with two initial photoproducts, the 17-electron species Co(CO)3(PMePh2) and the coordinatively unsaturated dimer Co2(CO)5(PMePh2)2. No evidence was found for photochemical formation of Co2(CO)6(PMePh2). Time-resolved spectroscopic studies allowed for the direct observation of transient species and for kinetics studies of certain reactions; for example, the reactions of Co(CO)3PMePh2 with CO and with PMePh2 gave the respective rate constants 1.5 × 105 and 1.2 × 107 M−1 s−1, while the analogous reactions with Co2(CO)5(PMePh2)2 gave the rate constants of 2.6 × 106 M−1 s−1 and 3.9 × 107 M−1 s−1.  相似文献   

16.
The iron hydrido complex HFe(CO)2{P(OPh)3}{(PhO)2POC6H4} (1), was rapidly deprotonated by DBU or [BzMe3N][OH] in THF to afford the new carbonyl iron anion [Fe(CO)2{P(OPh)3}{(PhO)2POC6H4}] ([2]), containing an ortho-metallated triphenyl phosphite ligand. Complex [2] reacted with triorganostannyl and plumbyl salts and with halogens to give the octahedral FeII compounds Fe(CO)2{P(OPh)3}{(PhO)2POC6H4}(X) (X=SnPh3, 3; SnMe3, 4; PbPh3, 5; PbMe3, 6; Cl, 7; Br, 8; I, 9). The Group 14 complexes 3-6 were obtained in one isomeric form in which the PIII-donor atoms are mutually cis, the carbonyl ligands are cis and the P(OPh)3 and MR3 (M=Sn, Pb; R=Ph, Me) groups are trans as determined by solution-state IR, 31P and 13C NMR spectroscopic data. This geometry was confirmed for 3 by a single crystal X-ray diffraction study. The halide complexes, however, were obtained as a mixture of isomers. The major isomer (7, X=Cl; 8a, X=Br; 9a, X=I) has cis P atoms, trans CO groups and the halide located trans to the phosphorus atom of the ortho-metallated phosphite ligand. The structure of 9a was confirmed by an X-ray diffraction study. Two other isomers, designated 8b (X=Br) and 9b (X=I), with cis P atoms and cis CO groups were isolated from the reactions of [2] with Br2 and I2, respectively. The structure of the latter was established by X-ray crystallography and is related to 9a by exchange of the P(OPh)3 ligand and a carbonyl group such that the metal-bound C atom of the five-membered metallacycle is trans to CO. The stereo-geometry of 8b could not be unambiguously assigned from the spectroscopic data; however, two of the seven possible geometric isomers were suggested as plausible structures.  相似文献   

17.
The thermal reaction of Ru3(CO)12 with various carboxylic acids (benzoic, 4-hydroxyphenylacetic, ferrocenic, stearic, oleic, 4-(octadecyloxy)benzoic) in refluxing tetrahydrofuran, followed by addition of 5-(4-pyridyl)-10,15,20-triphenylporphyrin (L), gives the dinuclear complexes Ru2(CO)4(OOCR)2L2 (1: R = -C6H5, 2: R = -CH2-p-C6H4OH, 3: R = -C5H4FeC5H5, 4: R = -(CH2)16CH3, 5: R = -(CH2)7CHCH(CH2)7CH3, 6: R = -p-C6H4O(CH2)17CH3). Complexes 1-6 were characterised by IR, NMR, and ESI-MS as well as by elemental analysis. The UV-Vis spectra show the Soret band centred at 417 nm and the Q bands at 515, 550, 590 and 645 nm, respectively.  相似文献   

18.
Density functional theory (DFT) is used to understand the effect of hydrogen bonding solvents on the CO band position in the infrared (IR) spectrum of a mono-iron complex, trans-[FeII(CN)4(CO)2]2−. This mono-iron complex has received much attention recently due its potential relation to the biosynthesis of Fe-only hydrogenase enzymes. Our calculations show that the polar solvent molecules preferentially hydrogen bond to the cyano ligands in this complex. The effect of such hydrogen bonding on the electron density distribution is analyzed in terms of the population in natural bond orbitals (NBO). Our results show that the presence of hydrogen bonding to the cyano ligands decreases the extent of back bonding from the metal to the carbonyl ligand. This results in decreased electron density in the π orbitals of the carbonyl bond leading to a strengthening of the CO bond and a consequent blue shift in the IR band position of the carbonyl group. We also show that the extent of blue shift correlates with the number of nearest neighbor solvent molecules.  相似文献   

19.
Two new complexes, {[MnAu2(CN)4(NITpPy)2(H2O)2]}n (1) and {[Co(N(CN)2)2(NITpPy)2(H2O)2]}n (2), have been synthesized and characterized. The single-crystal X-ray analysis for the complexes 1 and 2 demonstrates that each M(II) (M = Mn or Co) ion assumes a distorted octahedral MN4O2 coordination polyhedron. Four nitrogen atoms come from the cyanide groups and the pyridyl rings in a common plane, and two oxygen atoms come from the H2O molecules in trans-positions. The structures of complexes 1 and 2 illustrate that aurophilicity and/or hydrogen bonding interactions play important roles in increasing dimensionality. Magnetic investigations on complexes 1 and 2 show the presence of weak antiferromagnetic interactions.  相似文献   

20.
The hydrothermal reaction of cobalt(II)oxalate di-hydrate, zinc oxide, and triethyl-orthophosphate, using 1,2-diaminoethane as structure directing template in water, produced two major crystal phases in almost equal amount: the purple crystals of [NH3-CH2CH2NH3][Co0.7Zn1.3(PO4)2] (1) and the red burgundy crystals of Co6.2(OH)4(PO4)4Zn1.80 (2), a new adamite type phase. The structure of [NH3-CH2CH2NH3] [Co0.7Zn1.3(PO4)2] (1) exhibits a 3D open framework built from PO4 and (Co/Zn)O4 tetrahedra, and (Co/Zn)O5 trigonal bipyramids, forming two major channels, an 8-membered ring channel and a 16-membered ring channel, that host the ethanediammonium ions. The Co6.2(OH)4(PO4)4Zn1.80 (2) is isomorphous with adamite-type M2(OH)XO4 structure, with a condensed vertex and edge sharing network of (Co/Zn)O5, and distorted CoO6, and PO4 subunits. The cobalt preference for higher coordination numbers is displayed in this structure, where the octahedral sites are wholly occupied by cobalt. Thermal analysis confirmed that these compounds display high thermal stability.  相似文献   

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