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1.
《Polyhedron》1986,5(6):1191-1195
The homoleptic benzyl Mo2(CH2Ph)6 has been obtained by reaction of either MoCl4(thf)2 or Mo2(OPri)6 with Mg(CH2Ph)2. The dark-red, sparingly soluble complex has been characterized by 1H and 13C NMR as well as by a solid-state structure analysis. Pertinent bond distances (Å) and angles (°) for the unbridged, ethane-like molecule which contains crystallographic S6-symmetry are: MoMo = 2.175(1), MoC = 2.162(2), MoMoC = 97.61(6), and MoCC(Ph) = 98.9(1). 相似文献
2.
Senem Karahan Pelin Kose Elif Subasi Huseyin Alp Hamdi Temel 《Transition Metal Chemistry》2008,33(7):849-854
The hitherto unknown complexes, [M2(CO)6(μ-CO)(μ-L)], [M = Cr; 1, Mo; 2, W; 3] and [M2(CO)6(μ-CO)(μ-L′)], [M = Cr; 4, Mo; 5, W; 6] have been synthesized by the photochemical reactions of photogenerated intermediate, M(CO)5THF (M = Cr, Mo, W) with thio Schiff base ligands, N,N′-bis(2-aminothiophenol)-1,4-bis(2-carboxaldehydephenoxy)butane (H
2
L) and N,N′-bis(2-aminothiophenol)-1,7-bis(2-formylphenyl)-1,4,7-trioxaheptane (H
2
L′). The complexes have been characterized by elemental analysis, LC-mass spectrometry, magnetic studies, FT-IR and 1H NMR spectroscopy. The spectroscopic studies show that H
2
L and H
2
L′ ligands are converted to benzothiazole derivatives, L and L′ after UV irradiation and coordinated to the central metal as bridging ligands via the central azomethine nitrogen and sulphur
atoms in 1–6. 相似文献
3.
Kovalenko OO Brusylovets OA Kinzhybalo V Lis T Brusilovets AI 《Dalton transactions (Cambridge, England : 2003)》2011,40(18):4814-4817
The low-coordinate phosphorus compounds (Me(3)Si)(2)N-P=NSiMe(3), (Me(3)Si)(2)N-P(=S)=N(t)Bu and (Me(3)Si)(2)N-P(=NSiMe(3))(2) react with ((i)PrO)(3)M≡M(O(i)Pr)(3) (M = Mo, W) to form four- and five-membered metallacycles with intact endocyclic or exocyclic M≡M triple bonds. The first four-membered planar metallacycles, containing an M≡M triple bond were obtained in reaction with (Me(3)Si)(2)N-P=NSiMe(3). 相似文献
4.
Matoga Dariusz Szklarzewicz Janusz Samotus Alina Burgess John Fawcett John Russell David R. 《Transition Metal Chemistry》2001,26(4-5):404-411
The interactions between [M(CN)8]4– (M = Mo or W) and pyrazine (pz) in the solid state and in aqueous solutions have been analysed. In strongly acidic solutions {pzH+, [M(CN)8]4–} ion pair formation is observed; the pyrazinium salts (pzH)2(H3O)2[Mo(CN)8]·0.5pz·3H2O and (pzH)2K(H3O)[W(CN)8]·H2O have been isolated. The X-ray crystal structure of the latter, and the spectroscopic properties of both, are described. The [W(CN)8]4– anion is approximately square antiprismatic (D4d), with different H-bond environments around the N atoms. The ligand-field photolysis of [M(CN)8]4– in the presence of pyrazine in neutral and alkaline solution results in the formation of tetracyanooxometallates(IV) in equilibrium with pentacyanooxometallates(IV) through the [M(CN)7(pz)]3– anions as intermediates. The formation of the [M(CN)6(pz)2]2– ion, postulated in the literature to be the final product of the alkaline photolysis, has definitively been excluded. 相似文献
5.
《Journal of organometallic chemistry》1986,299(3):347-355
Tris(substituted butadiene) complexes of molybdenum and tungsten have been prepared by the reduction of the metal halides with anthracene-activated magnesium in the presence of the appropriate diene. An X-ray diffraction study has shown tris(2,3-dimethylbutadiene)molybdenum and its tungsten analogue to be isomorphous, with each diene unit displaying a long—short—long bond alternation, and having short metal to terminal carbon atom distances, in marked contrast to the unsubstituted complexes. 相似文献
6.
Bi-Zhou Lin Guo-Hua Han Bai-Huan Xu Ling Bai Yun-Long Feng Hong Su 《Journal of Cluster Science》2008,19(2):379-390
A new hybrid material, (H2dien)2(Hamimi)2[Co3Mo12O24(OH)6(HPO4)6(PO4)2]2 · nH2O (1) (n = 5.26), was hydrothermally synthesized via a simultaneous in situ cyclization of acetic acid and diethylenetriamine to 1-(2-aminoethyl)-2-methyl-2-imidazoline. The sandwich-shaped [Co(Mo6P4)2] clusters in 1 are linked by tetrahedrally coordinated cobalt into two-dimensional layers. It is interesting that no 2-imidazoline group was observed when the starting Co(II) salt was replaced by Ni(II) salt under the same hydrothermal conditions, but it led to the isolation of (Hdien)2[NiMo12O24(OH)6(H2PO4)6(HPO4)2] · 2dien · 8H2O (2), in which the [Ni(Mo6P4)2] units are discrete. A probe reaction of the oxidation of acetaldehyde with H2O2 showed that both compounds have high catalytic activity in the reaction. Compound 1 crystallizes in the space group C2/c with a = 26.028(4), b = 12.3391(17), c = 25.555(4) Å, β = 98.876(12)°, V = 8109(2) Å3 and Z = 4. Compound 2 is in the space group P21/n with a = 13.206(3), b = 22.170(5), c = 13.627(3) Å, β = 103.437(5)°, V = 3880.7(15) Å3 and Z = 2. 相似文献
7.
《中国化学快报》1997,(2)
KadsllreIlinM(7s.8s-.1.4.3'-tril1letllop'-7"oxo-n0r-8'.9'-7.0.4'.8.5'-neolignan)u'asisolatedfrollltlleaerialpart0fPiperKadsl1ra(Cl1ois}')0l1\viI'].aCllinesetraditiol1aldrugusedf0rtlletreatll1el1tofil1naI11l11ati0nundrl1eul1laticcol1diti0l1s.Aspartof0urresearcl1xt,0rkontlletotals}'lltllcsisofbe11z0fura11oidncolignans,l"ereportl1eret11efirstlotalsi'ntl1esisofkadsurenil1Masitsrecel11icfonn.Tllep-lltlleticro[1leisdepic1edi1ltl1ef0lloxt'il1gsclleme.3.4-Dilnetl1on'cil1nam}'lcllloride6.readil}'a\… 相似文献
8.
《Polyhedron》1986,5(3):899-900
By using newer structural and NMR data for Mo2(O2CR)4 compounds with R = PhCH(OH) and CH3 the diamagnetic anisotropy of the Mo-Mo quadruple bonds has been estimated as −(210±30) × 10−36 m3 per molecule. 相似文献
9.
Lein M Harrison JA Nielson AJ 《Dalton transactions (Cambridge, England : 2003)》2011,40(40):10731-10741
For the d(0) complex [{Zr(CpSiMe(2)H)Cl(3)}(2)] which contains a linear Si-H···Zr interaction across the dimer, DFT calculations are in good agreement with X-ray structures. The BP86 functional shows a slightly stronger interaction than B3LYP but for qualitative purposes either functional is sufficient. QTAIM analysis shows a bond critical point (bcp) for the interaction, a small negative value for the total energy density [H((r))] and the H atomic basin decreases in energy, E(H), and atomic volume compared to the free ligand. NBO analysis showed E(2) for Si-H σ to Zr(dz(2)) donation at 42.8 kcal mol(-1) and a 34% spatial overlap for the interaction consistent with an inverse hydrogen bond. The Wiberg bond index for the interaction is 0.1735 (0.7205 for the Si-H bond), ν((Si-H)) and (1)J((Si-H)) at 2060 cm(-1) and 145.4 Hz compared to 2183 cm(-1) and 172.1 Hz in the free ligand. Using a "synthesis by computation" approach to forming like complexes, similar features were found for [{Hf(CpSiMe(2)H)Cl(3)}(2)]. The titanium complex [{Ti(CpSiMe(2)H)Cl(3)}(2)] does not contain any Si-H···Ti interaction as rotation about the C-Si bond of the ligand occurs to place the Si-H bond hydrogen closer to a terminal chloro ligand across the dimer. An increase in electron density on the metal in the d(2) complex [{Mo(CpSiMe(2)H)Cl(3)}(2)] results in a stronger interaction with a distinct QTAIM analysis bcp [ρ((r)) 0.0448 a.u.], a small negative value for H((r)) and a much reduced H atomic volume. NBO analysis shows E(2) for Si-H σ to Mo(dz(2)) donation at 143.1 kcal mol(-1) and a 29% spatial overlap. Mo(dz(2)) to Si-H σ* donation (back donation) is minimal [E(2) 1.3 kcal mol(-1), ~1% spatial overlap]. The Wiberg bond index is 0.3114 (0.5667 for the Si-H bond), ν((Si-H)) 2015 cm(-1) and (1)J((Si-H)) 120.6 Hz. 相似文献
10.
11.
12.
Seidler-Egdal RK Johansson FB Veltzé S Skou EM Bond AD McKenzie CJ 《Dalton transactions (Cambridge, England : 2003)》2011,40(13):3336-3345
A comparison of the electrochemical properties of a series of dinuclear complexes [M(2)(L)(RCO(2))(2)](+) with M = Mn or Co, L = 2,6-bis(N,N-bis-(2-pyridylmethyl)-sulfonamido)-4-methylphenolato (bpsmp(-)) or 2,6-bis(N,N-bis(2-pyridylmethyl)aminomethyl)-4-tert-butylphenolato (bpbp(-)) and R = H, CH(3), CF(3) or 3,4-dimethoxybenzoate demonstrates: (i) The electron-withdrawing sulfonyl groups in the backbone of bpsmp(-) stabilize the [M(2)(bpsmp)(RCO(2))(2)](+) complexes in their M(II)(2) oxidation state compared to their [M(2)(bpbp)(RCO(2))(2)](+) analogues. Manganese complexes are stabilised by approximately 550 mV and cobalt complexes by 650 mV. (ii) The auxiliary bridging carboxylato ligands further attenuate the metal-based redox chemistry. Substitution of two acetato for two trifluoroacetato ligands shifts redox couples by 300-400 mV. Within the working potential window, reversible or quasi-reversible M(II)M(III)? M(II)(2) processes range from 0.31 to 1.41 V for the [Co(2)(L)(RCO(2))(2)](+/2+) complexes and from 0.54 to 1.41 V for the [Mn(2)(L)(RCO(2))(2)](+/2+) complexes versus Ag/AgCl for E(M(II)M(III)/M(II)(2)). The extreme limits are defined by the complexes [M(2)(bpbp)(CH(3)CO(2))(2)](+) and [M(2)(bpsmp)(CF(3)CO(2))(2)](+) for both metal ions. Thus, tuning the ligand field in these dinuclear complexes makes possible a range of around 0.9 V and 1.49 V for the one-electron E(M(II)M(III)/M(II)(2)) couple of the Mn and Co complexes, respectively. The second one-electron process, M(II)M(III)? M(III)(2) was also observed in some cases. The lowest potential recorded for the E°(M(III)(2)/M(II)M(III)) couple was 0.63 V for [Co(2)(bpbp)(CH(3)CO(2))(2)](2+) and the highest measurable potential was 2.23 V versus Ag/AgCl for [Co(2)(bpsmp)(CF(3)CO(2))(2)](2+). 相似文献
13.
Summary The question of the hybridization of the atomic orbitals of Mo in the Mo(CN)8
4– ion is examined, and it is shown that the dodecahedral structure can exist without the participation off electrons. 相似文献
14.
Yu. P. Barinova A. L. Bochkarev Yu. E. Begantsova L. N. Bochkarev Yu. A. Kurskii G. K. Fukin A. V. Cherkasov G. A. Abakumov 《Russian Journal of General Chemistry》2010,80(10):1945-1953
The heteroelement-containing alkylidene imide complexes with molybdenum and tungsten Et3SiCH=Mo(NAr)(OR)2 (I), Et3 ECH=W(NAr)(OR)2 (E = Si (II), Ge (III); Ar = 2,6-i-Pr2C6H3; R=CMe2 CF3) and π-complex (RO)2(ArN)Mo(CH2=CH-GeEt3) (IV) were synthesized by the reaction of Alkyl-CH=M(NAr) (OR)2 (M=Mo, W; Alkyl = t-Bu, PhMe2C) with organosilicon and organogermanium vinyl reagents Et3ECH=CH2 (E = Si, Ge). The structure of compounds I–III was determined by X-ray diffraction (XRD). The complexes I–IV are active initiators of metathesis polymerization of cycloolefins. 相似文献
15.
《Journal of Coordination Chemistry》2012,65(16):1807-1811
The complexes [M(CO)4(η2-H2L)] [M?=?Cr; 1, Mo; 2, W; 3] have been synthesized by photochemical reactions of VIB metal carbonyls [M(CO)6] [M?=?Cr,?Mo,?W] with N,N′-bis(salicylidene)-1,2-bis-(o-aminophenoxy)ethane (H2L) in THF and characterized by elemental analyses, FTIR, 1H?NMR and mass spectra. The H2L ligand is coordinated to the central metal as a bidentate ligand via the central azomethine nitrogen atoms in 1–3. 相似文献
16.
Electronic Structure of
TiAl-2M(M=V,Nb,Ta,Cr,Mo,W,Mn) Alloy 总被引:1,自引:0,他引:1
1INTRODUCTIONTitaniumaluminidesbasedonY-TiAlarereceivingconsiderableattentionaspo-tentialcandidatesformaterialsinhightemperatureaerospaceapplication.Theirlowdensity,hightemperaturescreepresistance,highoxidationresistanceandstrengthmakesthemexcellentpotentialenginematerials.Howevertheirlowductilityandlowfracturetoughnessatroom'temperaturesaremajorhindrancestotheirpracticaluti-lization.TheTiAlalloymayhaveanelongationabout2%t'},furtherimprovementisnecessarybeforethesematerialscouldbeusedin… 相似文献
17.
18.
《Journal of organometallic chemistry》1986,299(1):127-130
The new heterobimetallic phosphide-bridged compounds [AgL(μ-PR2)M(CO)5], (L = 1,10-phenanthroline or tricyclohexylphosphine: M = Cr, M, W) have been prepared from AgO3SCF3, M(CO)5PR2H and the ligand L in the presence of Et2NH or MeO− as base, and characterized by 31P NMR spectroscopy. 相似文献
19.
Jun Li 《Journal of Cluster Science》2002,13(1):137-163
The electronic structures and bonding of isopoly oxometalates M6O19
2– (M=Cr, Mo, W) have been investigated by using ab initio and relativistic density functional methods. We have discussed the role of the central oxygen atom and the (d-p) conjugation interactions between the metal and bridging oxygen atoms. It is found that there exist 12 three-centered two-electron (d-p-d) bonds for the three M4(-O)4 planar rings in M6O19
2– ions and these hexametalates are considered to have quasi-aromaticity. The (d-p) conjugation effects play essential role in stabilizing these cluster compounds, and the reduced (d-p) conjugation effects account for the instability of the isopoly oxochromate ion, Cr6O19
2–. The vibrational spectra and electronic spectra of M6O19
2– ions are evaluated and assigned theoretically and the calculated spectra are in fairly good agreement with the measured experimental results. 相似文献
20.
N. S. Kopelev Yu. D. Perfiliev Yu. M. Kiselev 《Journal of Radioanalytical and Nuclear Chemistry》1992,162(2):239-251
Sodium ferrates(IV) and (VI) were synthesized by the reaction between Fe2O3 and Na2O2 in a dry oxygen stream. The Mössbauer data for the obtained samples are presented (for Na2FeO3–=0.18(2) mm/s; for Na4FeO5–=–0.54(2) mm/s). It was shown that pure K2FeO4 and Cs2FeO4 can be obtained by heating Fe2O3 with apropriate alkali metal peroxides. 相似文献