首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 109 毫秒
1.
New complexes {M(CO)4[Ph2P(S)P(S)Ph2]} (M = Cr, Mo and W), (1a)–(3a), [(1a), M = Cr; (2a), M = Mo; (3a), M = W] and {M2(CO)10[-Ph2P(S)P(S)Ph2]} (M = Cr, Mo, W), [(1b)–(3b) [(1b), M = Cr; (2b), M = Mo; (3b), M = W]] have been prepared by the photochemical reaction of M(CO)6 with Ph2P(S)P(S)Ph2 and characterized by elemental analyses, f.t.-i.r. and 31P-(1H)-n.m.r. spectroscopy and by FAB-mass spectrometry. The spectra suggest cis-chelate bidentate coordination of the ligand in {M(CO)4[Ph2P(S)P(S)Ph2]} and cis-bridging bidentate coordination of the ligand between two metals in (M = Cr, Mo and W).  相似文献   

2.
Summary Reinvestigation of the reaction of M(CO)6 (M=Cr, Mo or W) with KOH has been found to provide a very convenient route to the K[M2H(CO)10] compounds (M=Cr, Mo or W). The reaction involving Cr(CO)6 yields new potassium derivatives containing [Cr2(CO)10]2– and [HCr(CO)5] species; also K[Cr2D(CO)10] is produced from the Cr(CO)6/KOD interaction in C2D5OD. The reaction involving two different group 6 metal carbonyls yields [MM(CO)10(-H)] (MM=CrMo, CrW or WMo) species as their K+ and PPN+ [bis(triphenylphosphine)iminium] salts.  相似文献   

3.
Summary Tetraazaadamantane (taad) reacts with group VI metal hexacarbonyls to give mononuclear (taad)M(CO)5 (M=Cr, Mo and W) derivatives. Mixed ligand metal tricarbonyls,cis- (L-L)(taad)M(CO)3 (L-L=o-phenanthroline or 2,2-bipyridine; M=Cr and Mo) have also been synthesised. Bromine or iodine reacts with (taad)M(CO)5 (M=Cr and Mo) to give [(taad)M(CO)5X]+X (X=Br or I). Nitrosyl chloride reacts with (taad)M(CO)5 at room temperature to yieldmer- (taad)M(CO)3NOCl while with the mixed (L-L)(taad)-Mo(CO)3 complex, a mixture of (L-L)Mo(NO)2Cl2 and (L-L)Mo(CO)2NOCl was obtained. An analogous reaction with (L-L)(taad)Cr(CO)3, gave only (L-L)Cr(NO)2Cl2 derivatives. The products have been characterised by elemental analysis, i.r. spectra, conductivity data and magnetic measurements.  相似文献   

4.
The reactions of half-sandwich diselenolate Mo and W complexes Cp#M(NO)(SePh)2 (M = Mo; Cp# = Cp (1a), MeCp (1b); M = W; Cp# = Cp (1c)) with (Norb)Mo(CO)4, Ni(COD)2 and Fe(CO)5 have been investigated. Treatment of (1a), (1b) and (1c) with (Norb)Mo(CO)4 in PhMe gave the bimetallic complexes: CpMo(NO)(-SePh)2Mo(CO)4 (2a), MeCpMo(NO)(-SePh)2Mo(CO)4 (2b) and CpW(NO)(-SePh)2Mo(CO)4 (2c) in moderate yields. Irradiation of (1a) and (1c) in the presence of Fe(CO)5 gave heterobimetallic complexes CpMo(CO)(-SePh)2Fe(CO)3 (3a) and CpW(NO)(-SePh)2Fe(CO)3 (3c). Ni(COD)2 reacts with two equivalents of (1a), (1b) and (1c) to give [CpMo(NO)(-SePh)2]2Ni (4a), [MeCpMo(NO)(-SePh)2]2Ni (4b) and [CpW(NO)(-SePh)2]2Ni (4c) in good yields. The new heterobimetallic complexes were characterized by i.r., 1H-n.m.r., 13C-n.m.r. and EI-MS spectroscopy.  相似文献   

5.
Five new complexes, [M(CO)5(apmsh)] [M = Cr; (1), Mo; (2), W; (3)], [Re(CO)4Br(apmsh)] (4) and [Mn(CO)3(apmsh)] (5) have been synthesized by the photochemical reaction of metal carbonyls [M(CO)6] (M = Cr, Mo and W), [Re(CO)5Br], and [Mn(CO)3Cp] with 2-hydroxyacetophenone methanesulfonylhydrazone (apmsh). The complexes have been characterized by elemental analysis, mass spectrometry, f.t.-i.r. and 1H spectroscopy. Spectroscopic studies show that apmsh behaves as a monodentate ligand coordinating via the imine N donor atom in [M(CO)5(apmsh)] (1–4) and as a tridentate ligand in (5).  相似文献   

6.
The photo-induced decarbonylation of CpCr(NO)(CO)2 (1a) in MeCN solution in the presence of R2E2 (E = S, Se; R = Me, Ph) leads to the formation of chalcogenolato-bridged binuclear complexes Cp2Cr2(NO)2(-ER)2 [E = S; R = Me (2a), Ph (3a); E = Se, R = Me (4a), Ph (5a)] while reactions between CpM(NO)(CO)2 [M = Mo (1b), W (1c)] and Ph2E2 (E = S, Se) result in mononuclear complexes CpM(NO)(EPh)2 [M = Mo; E = S (9b), Se (10b); M = W, E = S (11c), Se (12c)]. The corresponding reactions of (1b) with Me2E2 (E = S, Se) yielded both mono and binuclear complexes: CpMo(NO)(SeMe)2 (8b), Cp2Mo2(NO)2(-EMe)2 [E = S (6b), Se (7b)]. The new complexes have been characterized by i.r., 1H-, 13C-n.m.r. spectra and by electron-impact mass spectrometry.  相似文献   

7.
3,6-Bis(2-pyridyl)pyridazine derivatives (n-dppn) react with hydrated rhodium(III) chloride and bromide (prepared in situ) to give cis-[Rh(n-dppn)2Cl2]PF6·xH2O (n = 5, 6, 7, 8) and cis-[Rh(n-dppn)2Br2]Br·xH2O (n = 5, 7) complexes, which have been characterized by elemental analyses, conductivity measurements, i.r., electronic and 1H- and 13C-n.m.r. spectra.  相似文献   

8.
[W(CO)5(pz)], pz=pyrazine, has been prepared by 365 nm photolysis of W(CO)6 in C6H6 or Me2CO at 22°C. The isolated product exhibits the typical signature i.r. and electronic spectral features of [W(CO)5L] (L=N-heterocycle) complexes, coordinated at the N-heterocyclic position, in agreement with prior studies of other workers. The room temperature 1H-n.m.r. spectrum in [2H6]acetone shows two singlets at 9.09 and 8.75 p.p.m. (J2,3=J5,6=5MHz), downfield of the free ligand resonance (8.61 p.p.m.), as anticipated for a stereochemically rigid pyrazine. Temperature dependence studies were carried out in diglyme solvent from 298 to 393K in search of evidence for a 1,4-metallotropic shift of the coordinated ligand. The singlets of the separate adjacent (H-2 and H-6) protons and removed (H-3, H-5) protons remained sharp even up to 373K where ligand dissociation destroyed the complex. Free pyrazine is not in rapid exchange with the coordinated pyrazine over the entire temperature range. These results stand in contrast to the 1,2-shift observed in a previous study for [W(CO)5(pyd)], pyd=pyridazine. Pyridazine has greater -donation and -acceptor power compared with pyrazine, which should significantly raise the kinetic barrier to bond-breaking of the W-pyd bond versus W-pz bond. This apparently leads to facile dissociation rather than a 1,4-shift with [W(CO)5(pz)].  相似文献   

9.
Syntheses of [Me3SbM(CO)5] [M = Cr (1), W (2)], [Me3BiM(CO)5] [M = Cr (3), W (4)], cis-[(Me3Sb)2Mo(CO)4] (5), [tBu3BiFe(CO)4] (6), crystal structures of 1-6 and DFT studies of 1-4 are reported.  相似文献   

10.
Liu  Xiang  Gao  Yi-Ci  Su  Zhong-Xing  Wang  Yao-Yu  Shi  Qi-Zhen 《Transition Metal Chemistry》1999,24(6):666-668
Two novel telluroether-disubstituted metal carbonyls, [(R2Te)M(CO)4]2(M = Mn or Re; R = p-MeOC6H4), were prepared from [M2(CO)10] by an oxygen atom transfer. The axial CO is replaced by the telluroether when [M2(CO)10] reacts with a new kind of oxygen transfer reagent, R2TeO, under mild conditions. The products were characterized by elemental analysis, i.r., 1H- and 13C-n.m.r., and FAB-mass spectra. The configuration of the substituted carbonyl is unique, i.e. the 1, l-diax isomer.  相似文献   

11.
The thermal dissociation of gaseous Mo(CO)6 and W(CO)6 in an argon carrier gas, Mo(CO)6 → Mo(CO)5 + CO (1) and W(CO)6 → W(CO)5 + CO (2), is studied over temperature ranges of ∼585–685 K for (1) and ∼690−810 K for (2) at a total gas concentrations of 4 × 10−6 and 4 × 10−5 mol/cm3 by using the shock tube technique in conjunction with absorption spectrophotometry. The measured rate constants are extrapolated to the high-pressure limit by means of a newly developed procedure, with the resultant expressions for the indicated temperature ranges reading as kd1,∞(T),[s−1] = 1016.12 ± 0.68exp[(−148.8 ± 8.1 kJ/mol)/RT] and kd2,∞(T),[s−1] = 1015.93 ± 0.63exp[(−171.7 ± 8.9 kJ/mol)/RT]. Comparison of the high-pressure dissociation rate constants with the published data revealed a considerable discrepancy, a tentative explanation of which is given. Based on the obtained high-pressure dissociation rate constants and the available data on the high-pressure room-temperature rate constants for the reverse reaction of recombination, the first bond dissociation energies for these molecules are evaluated and compared with previous determinations, both theoretical and experimental. The enthalpies of formation of Mo(CO)5 and W(CO)5 are determined: ΔfH°(Mo(CO)5, g, 298.15 K) = −644.1 ± 5.6 kJ/mol and ΔfH°(W(CO)5, g, 298.15 K) = −581.9 ± 6.6 kJ/mol. Based on the enthalpies of formation of Mo(CO)5, W(CO)5, Mo(CO)6, and W(CO)6, and the published molecular parameters of these four species, their thermochemical functions are calculated and presented in the form of NASA seven-term polynomials.  相似文献   

12.
Wang  Mei  Miguel  Daniel  Riera  Víctor  Bois  Claudette  Jeannin  Yves 《Transition Metal Chemistry》2001,26(4-5):566-569
A novel dimolybdenum complex [(3-C3H5)(CO)2Mo(-S2CPCy3)Mo(3-CH2CMeCH2)(CO)2], obtained by reacting the [(CO)2(3-C3H5)Mo(-S2CPCy3)Mo(CO)3] anion with an excess of ClCH2CMe=CH2, has been characterized by i.r., 31P{1H}, 1H- and 13C-n.m.r. spectroscopy and by elemental analysis. The crystal structure of the complex, determined by X-ray diffraction, shows a definite preference for the central carbon of the S2CPCy3 bridge to bind to the Mo(2) atom coordinated by 3-2-methylallyl, rather than the Mo(1) atom attached to unsubstituted 3-allyl ligand.  相似文献   

13.
Synergistic extraction of hexavalent uranium and plutonium as well as trivalent americium was studied in HNO3 with thenoyl, trifluoro-acetone (HTTA)/1-phenyl, 3-methyl, 4-benzoyl pyrazolone-5 (HPMBP) in combination with neutral donors viz, DPSO, TBP, TOPO (mono-functional) and DBDECMP, DHDECMP, CMPO (bi-functional) with wide basicity range using benzene as dileunt. A linear correlation was observed when the equilibrium constant log Ks for the organic phase synergistic reaction of both U(VI) and Pu(VI) with either of the chelating agents HTTA or HPMBP was plotted vs. the basicity (log Kh) of the donor (both mono- and bi-functional) indicating bi-functional donors also behave as mono-functional. This was supported by the thermodynamic data (G 0, H 0, S 0) obtained for these systems. The organic phase adduct formation reactions were identified for the above systems from the thermodynamic data. In the Am(III) HTTA system log K s values of bi-functional donors were found to be very high and deviate from the linear plot (log K s vs. log K h ) obtained for mono-functional donors, indicating that they function as bi-functional for the Am(III)/HTTA system studied. This was supported by high +ve S 0 values obtained for this system.  相似文献   

14.
Reactions of monooxidized thioyl and selenoyl bis(phosphanyl)amine ligands C10H7‐1‐N(P(E)Ph2)(PPh2) [E = S ( 1 ), Se ( 2 )] with Mo(CO)4(pip)2 and W(CO)4(cod) afforded the complexes [M(CO)4{ 1 ‐κ2P,S}] [M = Mo ( 3 ), W ( 4 )] and [M(CO)4{ 2 ‐κ2P,Se}] [M = Mo ( 5 ), W ( 6 )]. Complexes 3 – 6 were characterized by multinuclear NMR (1H, 13C, 31P, and 77Se NMR) and IR spectroscopy. Crystal‐structure determinations were carried out on 3 , 5 , and 6 , which represent the first examples of structurally characterized complexes of such ligands with group‐6 metal carbonyls.  相似文献   

15.
Treatment of [Cp′MH(CO)3] (M = Mo, W; Cp′ = η5-C5H5 (Cp), η5-C5Me5 (Cp*)) with 1/8 equiv of S8 in THF, followed by the reaction with dppe under UV irradiation, gave new mono(hydrosulfido) complexes [Cp′M(SH)(CO)(dppe)] (Cp′ = Cp: M = Mo (5), W (6); Cp′ = Cp*: M = Mo (7), W (8); dppe = Ph2PCH2CH2PPh2). When 5 and 6 dissolved in THF were allowed to react with [RhCl(PPh3)3] in the presence of base, heterodinuclear complexes with bridging S and dppe ligands [CpM(CO)(μ-S)(μ-dppe)Rh(PPh3)] (M = Mo (9), W(10)) were obtained. Semi-bridging feature of the CO ligands were also demonstrated. Upon standing in CH2Cl2 solutions, 9 and 10 were converted further to the dimerization products [(CpM)2{Rh(dppe)}22-CO)23-S)2] (M = Mo (13), W). Detailed structures of mononuclear 7 and 8, dinuclear 9 and tetranuclear 13 have been determined by the X-ray diffraction.  相似文献   

16.
Summary Improved preparations ofcis-[LMo(CO)4],cis-[L2Mo(CO)2], and [LMo(CO)3P] where L=N, N-ethylenebis(1, 2-dimethylpyrazole-3-carboxaldeneimine) and P=P(p-MeOC6H4)3, P(p-MeC6H4)3, P(p-ClC6H4)3 or P(o-MeC6H4)3 are reported. The compounds were characterized by elemental analysis and i.r., electronic and31P n.m.r. spectra. The (CO) values for the nonphosphine complexes indicate Mo(4d)–L(*) back-bonding. Furthermore, L exists in two different configurations in the [{LMo(CO)4}2] and the monomeric derivatives. Electronic spectral data are discussed in terms of the effect of the -acceptor tendency of the Mo(4d)–L(*) back bonding.31P n.m.r. and i.r. data of the phosphine-containing compounds indicate that the more electron-withdrawing substituents on the phosphines gave larger31P coordination chemical shifts and larger CO frequencies.  相似文献   

17.
Photolysis of hexacarbonyltungsten(0) in the presence of acryloylferrocene in n-hexane solution at 10 °C yields pentacarbonyl(η2-acryloylferrocene)tungsten(0) (1) as the only photo-substitution product, different from the general reaction pattern observed for the Group 6 metal carbonyls with other olefins. W(CO)52-acryloylferrocene) (1) decomposes in solution to the parent hexacarbonyltungsten(0) and free acryloylferrocene. Trimethylphosphite was introduced as ligand into the molecule to increase the stability. The photolysis of pentacarbonyl(trimethylphosphite)tungsten(0) in the presence of acryloylferrocene in n-hexane solution at 10 °C yields only cis-W(CO)4[P(OCH3)3](η2-acryloylferrocene) (2) as the monosubstitution product. Both η2-acryloylferrocene complexes (1 and 2) could be isolated and characterized by MS, IR and NMR spectroscopy. The trimethylphosphite complex (2) is found to be even less stable than W(CO)52-acryloylferrocene) (1).  相似文献   

18.
(o-Methylphenyl)acetylene polymerized with high yields in the presence of W and Mo catalysts. W catalysts were more active than the corresponding Mo catalysts. The weight-average molecular weight of the polymer formed with W(CO)6–CCl4hv reached 8 × 105, being higher than the maximum value (ca. 2 × 105) for poly(phenylacetylene). The polymer had the structure $\rlap{--} [{\rm CH} \hbox{=\hskip-1pt=} {\rm C}(o - {\rm CH}_3 {\rm C}_6 {\rm H}_4 )\rlap{--} ]_n $. The stereochemical structure of the main chain could be determined by 13C-NMR; the cis content varied in a range of 41–61% depending on the polymerization conditions. The present polymer was thermally more stable than poly(phenylacetylene) according to thermogravimetric analysis. Interestingly, this polymer possessed deeper color than poly(phenylacetylene), and showed a fairly strong absorption in the visible region.  相似文献   

19.
Jia  Wen-Li  Tang  Liang-Fu  Wang  Zhi-Hong  Chai  Jian-Fang  Wang  Ji-Tao 《Transition Metal Chemistry》2001,26(4-5):400-403
A series of carbonylchromium and tungsten complexes containing substituted pyrazole ligands, M(CO)5L, have been synthesized by the photochemical reactions of substituted pyrazoles with M(CO)6 (M = Cr or W). Their electrochemical behavior, investigated by cyclic voltammetry, indicates that the chromium complexes exhibit one reversible or quasi-reversible couple corresponding to a one-electron oxidation, whereas the tungsten complexes have one irreversible oxidation process. The crystal structure of W(CO)5L [L = 3(5)-t-butylpyrazole] was determined by X-ray diffraction, indicating that 3(5)-t-butylpyrazole is a monodentate ligand, and that the central metal is six-coordinate with a quasi-octahedral coordination geometry. All new compounds were characterized by elemental analyses, i.r., 1H-n.m.r. and by 13C-n.m.r. in the case of the tungsten complexes.  相似文献   

20.
Summary 13C-n.m.r. spectra of (-SR)2Fe2(CO)6, (-SR)2Fe2(CO)5P(n-Bu)3 and (-X)2Fe2(CO)6 (X=S or Se) show that the solid state structure is maintained in solution. N.m.r. evidence indicates that two isomeric species, not separable by means of the usual physicochemical methods, are present for (-SPh)2Fe2(CO)6 with an overwhelming predominance of theanti form. The phosphine substitutes a COtrans to the iron-iron bond. For any of the iron chalcogen derivatives examined, variable temperature13C-n.m.r. spectra show that carbonyl exchange occur in one step. The energy barrier for the exchange of carbon monoxide in the phosphine derivative is lower than that in the unsubstituted complex.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号