Ein- und zwei-dimensionale Multikern NMR-Spektroskopie an den isomeren Halbsandwich-Komplexen cis- und trans-[(η5-C5H5)W(CO)2(H)PMe3]

Wrackmeyer, Bernd; Alt, Helmut G.; Maisel, Heidi E.

doi:10.1016/0022-328x(90)80090-m

Cited by 60 publications

(43 citation statements)

References 14 publications

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“…276 The cis and trans isomers o f the monosubstituted product interconvert rapidly at room temperature but the fluxionality can be frozen out at -50 °C, when two hydride peaks become visible in the J H NMR with J(HP) o f -65 Hz and 25 Hz, respectively; a detailed NMR study has determined the signs of the coupling constants. 277 Similar spectra are observed for other complexes o f this type. The isonitrile species [MH(CO) 2 (CNR)Cp] (M = Mo, W; R = Me, Bu l for Cp, Cp*) have also been prepared.…”

Section: [Mh(co) 3 Cp] and Related Compoundssupporting

confidence: 76%

Cyclopentadienyl Complexes of Chromium, Molybdenum and Tungsten

Morris

1995

Comprehensive Organometallic Chemistry II

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Section: [Mh(co) 3 Cp] and Related Compoundssupporting

confidence: 76%

Cyclopentadienyl Complexes of Chromium, Molybdenum and Tungsten

Morris

1995

Comprehensive Organometallic Chemistry II

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“…By recalling that 2 J(PC) couplings in complexes of the type [MCpX(CO) 2 (PR 3 )] (M = Mo, W; X = halogen, alkyl, hydride, etc.) usually follow the order Jcis > Jtrans, 25,26 we can safely assign the singlet resonances at 234.0 and 231.8 ppm to the carbonyl ligands trans to phosphorus.…”

Section: Structural Characterization Of Fluorophosphide Complexesmentioning

confidence: 83%

Proton induced P–H and Mo–H bond activation at the phosphide bridged dimolybdenum complexes [Mo₂Cp₂(µ-H)(µ-PHR)(CO)₄] (R = Cy, 2,4,6-C₆H₂R′₃; R′ = H, Me,^tBu)

et al. 2004

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The new hydride complexes [Mo2Cp2(mu-H)(mu-PHR)(CO)4] having bulky substituents (R = 2,4,6-C(6)H2tBu3= Mes*, R = 2,4,6-C6H2Me3= Mes) have been prepared in good yield by addition of Li[PHR] to the triply bonded [Mo2Cp2(CO)4] and further protonation of the resulting anionic phosphide complex [Mo2Cp2(mu-PHR)(CO)4]-. Protonation of the Mes* compound with either [H(OEt2)2][B{3,5-C6H3(CF3)2}4] or HBF4.OEt2 gives the cationic phosphinidene complex [Mo2Cp2(mu-H)(mu-PMes*)(CO)4]+ in high yield. In contrast, protonation of the analogous hydride compounds with Mes or Cy substituents on phosphorus give the corresponding unsaturated tetracarbonyls [Mo2Cp2(mu-PHR)(CO)4]+, which are unstable at room temperature and display a cis geometry. Decomposition of the latter give the electron-precise pentacarbonyls [Mo2Cp2(mu-PHR)(mu-CO)(CO)4]+, also displaying a cis arrangement of the metal fragments. In the presence of BF4- as external anion, fluoride abstraction competes with carbonylation to yield the neutral fluorophosphide hydrides [Mo2Cp2(mu-H)(mu-PFR)(CO)4]. Similar results were obtained in the protonation reactions of the hydride compounds having a Ph substituent on phosphorus. In that case, using HCl as protonation reagent gave the chloro-complex [Mo2ClCp2(mu-PHPh)(CO)4] in good yield. The structures and dynamic behaviour of the new compounds are analyzed on the basis of solution IR and 1H, 31P, 19F and 13C NMR data as well as the X-ray studies carried out on [Mo2Cp2(mu-H)(mu-PHMes)(CO)4](cis isomer), [Mo2Cp2(mu-H)(mu-PFMes)(CO)4](trans isomer), [Mo2Cp2(mu-PHCy)(mu-CO)(CO)4](BF4) and [Mo2ClCp2(mu-PHPh)(CO)4].

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“…8 Coupling between phosphine and phosphide P atoms was found to be higher for isomers 7 (J PP ) 40-29 Hz) than for isomers 4 (J PP ) 11-12 Hz). By considering the general trends for 2 J XY in complexes of the type CpMXYL 2 , 9,10 we can then propose a trans relative arrangement of the phosphide and diphosphine ligands in isomers 4, while these ligands would exhibit a cis arrangement in isomers 7. The W-P (phosphide) couplings are in agreement with the above structural proposals, as J PW in isomers 4 (184-171 Hz) are slightly higher than the P-W couplings measured for complexes 7 .…”

Section: Resultsmentioning

confidence: 99%

“…The coordination number around W in compounds 9 or 10 is then higher than in 8, and the W-P couplings are accordingly lower, falling from ca. 400 Hz in 8 down to 300 Hz (10) or 260 Hz (9) in the alkyne-bridged products. We have noted previously that the J PW values are a useful diagnostic tool to detect changes in coordination numbers for organometallic tungsten compounds.…”

Section: Reaction Pathways In the Formation Of Compounds 4 It Is Clementioning

confidence: 97%

Chemistry of Highly Electrophilic Binuclear Cations. 3. Reactivity of [W₂(η⁵-C₅H₅)₂(μ-CO)(CO)₂(μ-Ph₂PCH₂PPh₂)][B{3,5-C₆H₃(CF₃)₂}₄]₂toward Small Donor Molecules

et al. 2003

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Reaction of the unsaturated tricarbonyl complex [W 2 Cp 2 (µ-CO)(CO) 2 (µ-dppm)](BAr′ 4 ) 2 with HSPh leads to the thiolate-bridged complex [W 2 Cp 2 (µ-SPh)(µ-CO)(CO) 2 (µ-dppm)](BAr′ 4 ), which is obtained as a mixture of two isomers. This reaction proceeds faster in the presence of a base (1,8-diazabicyclo[5.4.0]undec-7-ene, DBU), as expected. The title compound also reacts at room temperature with stoichiometric amounts of phosphines HPRwhich display a trans relative geometry of their phosphide and diphosphine ligands. Deprotonation of these hydride complexes with DBU gives the cis phosphide compounds [W 2 Cp 2 (µ-PR 1 R 2 )(CO) 2 (µ-dppm)](BAr′ 4 ), through an unexpected reduction and dehydrogenation/isomerization pathway. This overall deprotonation process is not reversible, and treatment of the latter compound with HBF 4 ‚OEt 2 gives the hydride isomer cis-[W 2 Cp 2 (µ-H)(µ-PR 1 R 2 )(CO) 2 (µ-dppm)](BAr′ 4 )(BF 4 ), which displays a strong hydrogen bond interaction between the bridging hydride ligand and the external BF 4anion. Treatment of the title compound with N 2 CHSiMe 3 or HCtC(p-tol) leads to dicarbonyls [W 2 -Cp 2 {µ-κ 1 -N 2 CH(SiMe 3 )}(CO) 2 (µ-dppm)](BAr′ 4 ) 2 or [W 2 Cp 2 {µ-η 2 :η 2 -HCC(p-tol)}(CO) 2 (µ-dppm)]-(BAr′ 4 ) 2 (two isomers), displaying four-electron-donor diazoalkane or alkyne bridging ligands.

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Ein- und zwei-dimensionale Multikern NMR-Spektroskopie an den isomeren Halbsandwich-Komplexen cis- und trans-[(η5-C5H5)W(CO)2(H)PMe3]

Cited by 60 publications

References 14 publications

Cyclopentadienyl Complexes of Chromium, Molybdenum and Tungsten

Cyclopentadienyl Complexes of Chromium, Molybdenum and Tungsten

Proton induced P–H and Mo–H bond activation at the phosphide bridged dimolybdenum complexes [Mo₂Cp₂(µ-H)(µ-PHR)(CO)₄] (R = Cy, 2,4,6-C₆H₂R′₃; R′ = H, Me,^tBu)

Chemistry of Highly Electrophilic Binuclear Cations. 3. Reactivity of [W₂(η⁵-C₅H₅)₂(μ-CO)(CO)₂(μ-Ph₂PCH₂PPh₂)][B{3,5-C₆H₃(CF₃)₂}₄]₂toward Small Donor Molecules

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Ein- und zwei-dimensionale Multikern NMR-Spektroskopie an den isomeren Halbsandwich-Komplexen cis- und trans-[(η5-C5H5)W(CO)2(H)PMe3]

Cited by 60 publications

References 14 publications

Cyclopentadienyl Complexes of Chromium, Molybdenum and Tungsten

Cyclopentadienyl Complexes of Chromium, Molybdenum and Tungsten

Proton induced P–H and Mo–H bond activation at the phosphide bridged dimolybdenum complexes [Mo2Cp2(µ-H)(µ-PHR)(CO)4] (R = Cy, 2,4,6-C6H2R′3; R′ = H, Me,tBu)

Chemistry of Highly Electrophilic Binuclear Cations. 3. Reactivity of [W2(η5-C5H5)2(μ-CO)(CO)2(μ-Ph2PCH2PPh2)][B{3,5-C6H3(CF3)2}4]2toward Small Donor Molecules

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Proton induced P–H and Mo–H bond activation at the phosphide bridged dimolybdenum complexes [Mo₂Cp₂(µ-H)(µ-PHR)(CO)₄] (R = Cy, 2,4,6-C₆H₂R′₃; R′ = H, Me,^tBu)

Chemistry of Highly Electrophilic Binuclear Cations. 3. Reactivity of [W₂(η⁵-C₅H₅)₂(μ-CO)(CO)₂(μ-Ph₂PCH₂PPh₂)][B{3,5-C₆H₃(CF₃)₂}₄]₂toward Small Donor Molecules