Tetrakis(trimethylphosphine)tungsten(II) trimethylphospinate hydride

[(Dimethylphosphino-κP)methyl-κC]hydrotetrakis(trimethylphosphine)tungsten
Names
IUPAC name
[(Dimethylphosphino-κP)methyl-κC]hydrotetrakis(trimethylphosphine)tungsten
Identifiers
3D model (JSmol)
  • InChI=1S/4C3H9P.C3H8P.W.H/c5*1-4(2)3;;/h4*1-3H3;1H2,2-3H3;;
    Key: JEOJFJRETFUFNG-UHFFFAOYSA-N
  • [H][W]CP(C)C.CP(C)C.CP(C)C.CP(C)C.CP(C)C
Properties
C15H45P5W
Molar mass 564.23 g·mol−1
Appearance Yellow crystalline solid
Hydrolysis
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Tetrakis(trimethylphosphine)tungsten(II) trimethylphospinate hydride is the organotungsten compound with the formula W(PMe3)4(η2-CH2PMe2)H. In this complex, four trimethylphosphine ligands are bonded to tungsten. The remaining ligands are hydride and an 2-CH2PMe2. In this complex, the oxidation state of W is usually assigned as 2+, denoted W(II). The complex reacts with many simple reagents.[1]

Synthesis

W(PMe3)4(η2-CH2PMe2)H can be synthesized by treating tungsten hexachloride with trimethylphosphine and sodium.[2][3] WCl6 with excess PMe3 and H2 produces W(PMe3)4(η2-CH2PMe2)H in a 3:1 mixture with W(PMe3)5H2.[4] The co-condensation method produces only W(PMe3)4(η2-CH2PMe2)H, and the Na(K) alloy method produces a mixture of W(PMe3)4(η2-CH2PMe2)H and W(PMe3)6 only under vast excess of PMe3.[5]

W(PMe3)4(η2-CH2PMe2)H is thermodynamically favored relative to W(PMe3)6, as described in the equation:[5][6]

W(PMe3)6 W(PMe3)4(η2−CH2PMe2)H + PMe3 ΔGrxn = –1.73 kcal mol−1

W(PMe3)5, a 16 electron, d6 complex, has been proposed as an unstable intermediate between W(PMe3)4(η2-CH2PMe2)H and W(PMe3)6. The rate-determining step from W(PMe3)6 is dissociation of PMe3.[6] Isotopic labeling and the NMR studies indicate that W(PMe3)4(η2-CH2PMe2)H is fluxional such that all methyl groups are equivalenced.[2][4]

Reactivity

Small molecule substrates: H2, CO, N2, CO2, SiH4

W(PMe3)4(η2-CH2PMe2)H reacts with H2 to give W(PMe3)5(H)2 and W(PMe3)4(H)4.[7] With HD, W(PMe3)4(η2-CH2PMe2)H converts to W(PMe3)5HD or W(PMe3)4(η2-HD) in PMe3 solvent.[8]

W(PMe3)4(η2-CH2PMe2)H adds N2 to give W(PMe3)5(N2).[7]

In 2 atmospheres of CO, W(PMe3)4(η2-CH2PMe2)H gives fac-W(PMe3)3(CO)3.[3]

W(PMe3)4(η2-CH2PMe2)H reacts with 3 atmosphere of 1:1 CO2/H2 gas mix to produce W(PMe3)4(κ2-O2CO)H2 and a bimetallacyclic compound.[9][10]

W(PMe3)4(η2-CH2PMe2)H reacts with H2 to give W(PMe3)5(H)2 and W(PMe3)4(H)4.[7] With HD, W(PMe3)4(η2-CH2PMe2)H converts to W(PMe3)5HD or W(PMe3)4(η2-HD) in PMe3 solvent.[8]

The reaction of W(PMe3)4(η2-CH2PMe2)H with SiH4 yields W(PMe3)4(SiH3)2H2.[7] Organosilanes give a variety of products.[11]

Acids

HBF4 reacts with W(PMe3)4(η2-CH2PMe2)H in ether to give [W(PMe3)4(OH)2H2][BF4]2.[7] Several derivatives are known: W(PMe3)4H4, W(PMe3)4F2H2, and [W(PMe3)4F(H2O)H2]F.[3][7]

Hydrogen chloride reacts as follows:

W(PMe3)4(η2-CH2PMe2)H + 2 HCl → W(PMe3)4Cl2(H)2 + PMe3

The corresponding dibromide and diiodide form by salt metathesis.[12] Carboxylic acid reacts with W(PMe3)4(η2-CH2PMe2)H to give hydride complexes, e.g., W(PMe3)4(O2CR)H.[13]

π-systems

In 1-2 atmospheres of ethylene at room temperature, W(PMe3)4(η2-CH2PMe2)H reacts to form trans-W(PMe3)4(η2-C2H4)2.[3]

Upon subjecting W(PMe3)4(η2-CH2PMe2)H to 2 atmospheres of ethylene at 60 °C in the presence of light petroleum for a week, W(PMe3)2(η2-C4H6)2 is produced.[7] W(PMe3)4(η2-CH2PMe2)H will ligate to buta-1,3-diene when the latter is in vast excess and in the presence of light petroleum at 50 °C to make the same product as ethylene. W(PMe3)2(η2-C4H6)2 produces yellow crystals.[4]

Much like with ethylene, propylene (2 atm) also forms C-C bonds upon reaction with W(PMe3)4(η2-CH2PMe2)H and light petroleum at 70 °C. The resultant product is W(PMe3)3[η-CH2=C(Me)CH=C(cis-Me)H]H2.[7]

W(PMe3)4(η2-CH2PMe2)H, upon reaction with cyclopentadiene in light petroleum for five days, binds cyclopentadiene and dissociates two PMe3 ligands to generate W(η5-C5H5)(PMe3)3H, W(PMe3)4H4, W(PMe3)3H6, and trace W(η5-C5H5)2H2.[4][8] The crystals of this mixture are yellow and air-sensitive.[4]

In the reaction with quinoxaline (QoxH,HH) and its derivatives 6-methylquinoxaline (QoxMe,HH) and 6,7-dimethylquinoxaline (QoxMe,MeH), W(PMe3)4(η2-CH2PMe2)H forms [κ2-C2-C6RR'H2(NC)2]W(PMe3)4, (η4-C2N2-QoxR,R'H)W(PMe3)3H2 (vide infra), and W(PMe3)4H2 (R,R'=H, Me), wherein the first listed product is generated from C-C bond cleavage to form two W=C=B bond motifs. The latter two products are hypothesized to be formed from H2 generated from the C-C bond cleavage.[14]

Methanol

W(PMe3)4(η2-CH2PMe2)H, upon addition of methanol in an ethylene atmosphere, can form W(PMe3)4(CO)H2.[15]

W(PMe3)4(η2-CH2PMe2)H, upon MeOH ligation in an η2-fashion, dissociates PMe3 and forms W(PMe3)4(η2-CH2O)H2. This complex undergoes many similar reaction pathways as its precursor retron.[16]

Tungsten-tetrel multiple bonding

W(PMe3)4(η2-CH2PMe2)H, in pentane and at −20 °C, reacts with Ge(C6H3-2,6-Trip2)Cl (Trip=C6H2-2,4,6-iPr3, iPr=CH(CH3)2) to dissociate PMe3 and generate trans-[Cl(H)(PMe3)3W{=Ge(C6H3-2,6-Trip2)(CH2PMe2)}]. This green, air-sensitive complex can heated at 50 °C with toluene or left in ambient conditions with either toluene or pentane to yield the Ge≡C bond-containing complex, trans-[Cl(PMe3)4W≡Ge-C6H3-2,6-Trip2]. This brown, air-sensitive complex can also be directly generated from W(PMe3)4(η2-CH2PMe2)H by heating with toluene and Ge(C6H3-2,6-Trip2)Cl at 50 °C. trans-[Cl(PMe3)4W≡Ge-C6H3-2,6-Trip2] is, in turn, also a retron for further chemistry by substitution of the labile chloride ligand. Upon addition of lithium iodide in ether, chloride is substituted for iodide, forming red-brown trans-[I(PMe3)4W≡Ge-C6H3-2,6-Trip2]. With lithium dimethylamine in THF, the chloride is substituted for a hydride, generating red-brown, air-sensitive trans-[H(PMe3)4W≡Ge-C6H3-2,6-Trip2]. With potassium thiocynate in THF, chloride is substituted for thiocynate, forming dark brown trans-[(NCS)(PMe3)4W≡Ge-C6H3-2,6-Trip2].[17]

W(PMe3)4(η2-CH2PMe2)H with 0.5 equivalent of {Pb(Trip)Br2}2 and in toluene at 50 °C produces (PMe3)4BrW{≡Pb(C6H3-2,6-Trip2)}. Upon addition of lithium dimethylamine in THF, Br(PMe3)4W{≡Pb(C6H3-2,6-Trip2)} converts to brown, air-sensitive H(PMe3)4W{≡Pb(C6H3-2,6-Trip2)}. Alternatively, W(PMe3)4(η2-CH2PMe2)H, with 0.5 equivalent of {Pb(Trip)NMe2}2 (produced from the reaction of {Pb(Trip)Br2}2 with lithium dimethylamine) in toluene and at 80 °C, also produces H(PMe3)4W{≡Pb(C6H3-2,6-Trip2)}.[18]

Tungsten-chalcogenide multiple bonding

W(PMe3)4(η2-CH2PMe2)H forms a variety of brightly colored complexes with terminal W=E bonds (E =2.718 S, Se, Te). H2Se gives W(PMe3)4Se(H)2, which features a terminal selenide ligand and two hydride ligands. It reacts with H2S and H2Se to give W(PMe3)4(Se)(S) and W(PMe3)4(Se)2, respectively. In related behavior, H2S reacts with W(PMe3)4(η2-CH2PMe2)H to give W(PMe3)4(SH2)H2. The complex can be dehydrogenated to give trans-W(PMe3)4S2. trans-W(PMe3)4Te2, a rare complex with a terminal telluride ligand can be produced as well. Since H2Te is not easily available, elemental Te in the presence of PMe3 was used, implicating a role for the phosphine telluride Me3P=Te.[19][20]

The dichalcogenides W(PMe3)4(E)2 (E =S, Se, Te) reversibly bind aldehydes to give W(PMe3)2E2(η2-OCHR) (R = H, Ph).[21][19][22][20][23] Related tBuNC complexes have also been produced, e.g., trans, trans, trans-W(PMe3)2(CNtBu)2Se2.[21][19]

Hydrodesulfurization

When treated with thiophenes, benzothiophene, and dibenzothiophene, W(PMe3)4(η2-CH2PMe2)H inserts into the C-S bonds. All of these complexes react further with H2, resulting in hydrogenolysis of the C-S bonds. Such reactions are reminiscent of W-catalyzed hydrodesulfurization, a major process in refining petroleum.[24]

C-H bond activation

W(PMe3)4(η2-CH2PMe2)H reacts with phenols forming four- and five-membered oxometallacycles.[25] With PhOD, the first step is the deuterolysis of the W–C bond, forming W(PMe3)4(PMe2CH2D)(OPh)H. These phenoxide complexes are further reactive with H2[26]

More complex phenols, e.g., 2,2′-methylenebis(4,6-dimethylphenol) and calixarenes, are also reactive toward W(PMe3)4(h2-CH2PMe2)H.[27]

.[28]

Alkylidene generation

Upon the addition of bromobenzene, iodobenzene, or para-bromotoluene, W(PMe3)4(η2-CH2PMe2)H form the cation [W(PMe3)4(η2-CHPMe2)H]+ with the corresponding halide anion.[29]

Theoretical work

C-C bond activation mechanism

The novel activation of the aromatic C-C bond in QoxH by W(PMe3)4(η2-CH2PMe2)H under relatively mundane conditions inspired mechanistic theorizations. In their original publication, Sattler and Parkin suggested a mechanism in QoxH first acts as an L-type ligand from the N lone pair. The Qox ligand then changes its bonding behavior, with the bonding atoms shifting counterclockwise per Qox's numbering scheme. Upon reaching η2-C2 binding, the complex undergoes reductive elimination of its two hydrides to form H2. Finally, the complex cleaves its C-C bond to form the two W=C bonds.[14]

Miscione and coworkers – using the B3LYP functional with energy-adjusted pseudopotential[30] and DZVP basis sets — provided the first computational study of the proposed mechanism, wherein they provided a few pathways, building on Sattler and Parkin's work. The first pathway suggests that the hydride moves towards the tucked-in alkyl ligand to form W(PMe3)5 before QoxH binds. Upon the loss of a PMe3 ligand, Qox can then bond in an η2-N,C fashion, forming a hydride which subsequently moves to be trans to Qox. In the second pathway, PMe3 occurs first, followed by QoxH's ligation. Then, the agostic interaction is transformed into a standard PMe3 L-type ligand to join the first pathway in following the original proposed mechanism. The third pathway diverges from the first pathway at W(PMe3)5, wherein Qox instead interacts at the 2-H site before either bonding in a κ1-C fashion or losing a PMe3 to interact with both the 2-H and 3-H sites. Both intermediates then form (along with the loss of PMe3 in the former complex) a κ1-C complex with a 3-H interaction, before rejoining the original mechanism at the η2-C2 complex. Of these paths, path 2 is the least favored due to the ~30–40 kcal/mol energy barrier in breaking the agnostic interaction. Paths 1 and 3 are reported to be of roughly equal thermodynamic favorability with energy barriers mostly around 10–20 kcal/mol, until the maximum of the energy surface, the three-membered ring-containing η2-C2 intermediate (33.7 kcal/mol higher than W(PMe3)4(η2-CH2PMe2)H).[31] Miscione and coworker's results substantiate Sattler and Parkin's hypothesis that the ring strain in the η2-C2 complex facilitates the C-C bond cleavage.[14][31] They also report the reaction as being slightly net endergonic by 3.3 kcal/mol.[31]

Liu et al. — using the B3LYP* functional with the LANL2DZ and 6-31G(d,f) basis sets – proposed two mechanisms based on Sattler and Parkin's original proposal. Both pathways start by dissociating both equatorial PMe3 ligands in the beginning before binding QoxH and generating a κ1-N QoxH ligand. It then switches to η2-N,C-Qox with a hydride which must move to be trans to Qox. κ1-N Qox then transitions to κ1-C Qox, followed by the transformation into η2-N,C Qox. Dissociation of PMe3 follows suite. Liu et. al.'s mechanism suggests that the C-C bond is broken at this stage, with a two electron oxidation of tungsten to form a double bond to the already bound carbon and a single bond to the other. The latter carbon's C-H bond forms an agostic interaction with tungsten to account for the lost electron density. The complex then gains its second W–C bond along with a hydride ligand. At this point, the two pathways branch. In the first pathway, an axial PMe3 moves down to the equatorial plane along with loss of the W=C bonds and reformation of the C-C bond, allowing another PMe3 to associate and rejoining the original mechanism at the dihydride-containing η2-C2 Qox complex. The second pathway sees the two hydride ligands move such that they are cis to the W=C bonds before undergoing reductive elimination. PMe3 then associates, forming the final complex. Liu et. al. claims that the final step to C-C bond cleavage is the concerted, not stepwise, elimination of H2 and formation W=C bonds. Per their calculations, Sattler and Parkin's mechanism spans a range of 42.0 kcal/mol energy range, in large part due to the aforementioned concerted step. The second pathway was calculated to have energy barriers of ~10 kcal/mol in all steps post-branching, leaving the second PMe3 dissociation as the highest energy barrier in the mechanism. Liu et al.'s calculations suggest that the mechanism is exergonic, releasing a net 9.2 kcal/mol of energy.[32]

Li and Yoshizawa – using the B3LYP* functional with the LANL2TZ(f) and 6-31G(d,f) basis sets – also proposed two mechanisms which start with ligand dissociations. Both mechanisms start with the dissociation of an equatorial PMe3 ligand, before diverging. The first pathway sees the dissociation of the second equatorial PMe3, leaving the agostic interaction and the hydride. This complex then binds to QoxH, generating a κ1-N QoxH ligand. Qox then changes its binding to the η2-N,C fashion, as well generating a hydride bond, before breaking the agostic interaction to form a PMe3 L-type interaction. Another PMe3 ligates before Qox switches to η2-C2-type bonding as well as an H2 ligand. H2 dissociation, followed by C-C bond cleavage, then leads to the final product. In the second pathway, the agostic bond is broken for a PMe3 L-type interaction after the first PMe3 dissociation. QoxH then binds in a κ1-N fashion before changing to η2-N,C with a hydride bond to tungsten and rejoining pathway 1. Li and Yoshizawa concluded that, between their pathways, pathway 1 is the most thermodynamically favorable. The reformation of PMe3 after immediately after the first PMe3 dissociation in pathway 2 has a barrier of 26.3 kcal/mol relative to W(PMe3)4(η2-CH2PMe2)H. In contrast, the energy maximum of pathway 1 is from the H2 dissociation step shared by both pathways. Overall, Li and Yoshizawa's work suggest that the C-C bond mechanism is exergonic overall, with the product being 18.5 kcal/mol lower in energy relative to W(PMe3)4(η2-CH2PMe2)H.[33]

η4-C2N2 quinoxaline binding

The η4-C2N2-QoxH ligand is a novel binding behavior discovered from the reaction of W(PMe3)4(η2-CH2PMe2)H with QoxH. Miscione et al. and Liu et al. also investigated these mechanisms. The former group suggests that upon formation of W(PMe3)5 (vide infra), the tungsten undergoes the oxidative addition of H2, forming hydride bonds. Then, one PMe3 ligand is dissociated, allowing QoxH to bind, first in a η2-N,C fashion before switching to the final η4-C2N2 fashion via a 7.3 kcal/mol rearrangement energy barrier.[31] The latter group suggests that one PMe3 first dissociates, followed by the oxidative addition of H2, forming an ML6 complex. One of the axial PMe3 ligands is lost, allowing QoxH to bind, forming the η4-C2N2-QoxH ligand.[32] Both sets of calculations agree that the mechanism is net exergonic, with the product being ~20 kcal/mol lower in energy than W(PMe3)4(η2-CH2PMe2)H.[31][32]

[14][17][18][24]

See also

References

  1. ^ Green, Malcolm L. H.; Parkin, Gerard; Moynihan, Kelly J.; Prout, Keith (1 January 1984). "Formation of an η2-formaldehyde compound from methanol and its hydrogenation giving methanol". Journal of the Chemical Society, Chemical Communications (22): 1540. doi:10.1039/C39840001540. ISSN 0022-4936.
  2. ^ a b Gibson, Vernon C.; Grebenik, Peter D.; Green, Malcolm L. H. (1983). "Trimethylphosphine as a reactive solvent: synthesis and crystal structure of Ta(PMe3)3(η2-CH2–PMe2)(η2-CH–PMe2) and Synthesis of Related Molybdenum and Tungsten Compounds". J. Chem. Soc., Chem. Commun. (19): 1101–1102. doi:10.1039/C39830001101. ISSN 0022-4936.
  3. ^ a b c d Green, Malcolm L. H.; Parkin, Gerard; Chen, Mingqin; Prout, Keith (1986). "The chemistry of [W(PMe3)4(η2-CH2PMe2)H]: synthesis of hydroxy-hydrido, fluoro-hydrido, and silyl-hydrido derivatives and the dimerisation of ethylene and propene giving η4-diene derivatives. Crystal structure of [W(PMe3)4H2(OH2)F]F". J. Chem. Soc., Dalton Trans. (10): 2227–2236. doi:10.1039/DT9860002227. ISSN 0300-9246.
  4. ^ a b c d e Gibson, Vernon C.; Graimann, Christof E.; Hare, Philip M.; Green, Malcolm L. H.; Bandy, Judith A.; Grebenik, Peter D.; Prout, Keith (1985). "Trimethylphosphine as a reactive solvent: synthesis, crystal structures, and reactions of [Ta(PMe 3 ) 3 (η 2 -CH 2 PMe 2 )(η 2 -CHPMe 2 )] and [W(PMe3)4(η2 -CH2PMe2)H] and related studies". J. Chem. Soc., Dalton Trans. (10): 2025–2035. doi:10.1039/DT9850002025. ISSN 0300-9246.
  5. ^ a b Rabinovich, Daniel; Parkin, Gerard (June 1990). "Hexakis(trimethylphosphine)tungsten(0): synthesis, structure, and reactivity". Journal of the American Chemical Society. 112 (13): 5381–5383. Bibcode:1990JAChS.112.5381R. doi:10.1021/ja00169a073. ISSN 0002-7863.
  6. ^ a b Rabinovich, Daniel; Zelman, Ross; Parkin, Gerard (June 1992). "Synthetic, structural, and mechanistic studies of the carbon-hydrogen bond activation of phenols by tungsten complexes W(PMe3)6 and W(PMe3)4(η2-CH2PMe2)H". Journal of the American Chemical Society. 114 (12): 4611–4621. Bibcode:1992JAChS.114.4611R. doi:10.1021/ja00038a025. ISSN 0002-7863.
  7. ^ a b c d e f g h Green, Malcolm L. H.; Parkin, Gerard; Mingqin, Chen; Prout, Keith (1984). "Trimethylphosphine–tungsten chemistry: hydrido, silyl, fluoro, hydroxy, and aquo derivatives: crystal structure of [W(PMe3)4H2(OH2)F]F". J. Chem. Soc., Chem. Commun. (21): 1400–1402. doi:10.1039/C39840001400. ISSN 0022-4936.
  8. ^ a b c Green, Malcolm L. H.; Parkin, Gerard (1987). "Synthesis of (η-cyclopentadienyl)(trimethylphosphine)tungsten derivatives and related chemistry". J. Chem. Soc., Dalton Trans. (7): 1611–1618. doi:10.1039/DT9870001611. ISSN 0300-9246.
  9. ^ Green, Malcolm L.H.; Parkin, Gerard; O'Hare, Dermot; Wong, Luet-Lok; Derome, Andrew E. (December 1986). "The reaction of [W(PMe3)4(η2-CH2PMe2)H] with carbon dioxide and dihydrogen: characterisation of [{W(PMe3)3(η1-PMe2CH2)}2(C3H2O6)] using two-dimensional nuclear magnetic resonance spectroscopy". Journal of Organometallic Chemistry. 317 (1): 61–68. doi:10.1016/S0022-328X(00)99345-8.
  10. ^ Grice, Kyle A. (April 2017). "Carbon dioxide reduction with homogenous early transition metal complexes: Opportunities and challenges for developing CO2 catalysis". Coordination Chemistry Reviews. 336: 78–95. doi:10.1016/j.ccr.2017.01.007.
  11. ^ Zuzek, Ashley A.; Neary, Michelle C.; Parkin, Gerard (31 December 2014). "σ-Silane, Disilanyl, and [W(μ-H)Si(μ-H)W] Bridging Silylene Complexes via the Reactions of W(PMe3)4(η2-CH2PMe2)H with Phenylsilanes". Journal of the American Chemical Society. 136 (52): 17934–17937. Bibcode:2014JAChS.13617934Z. doi:10.1021/ja510703s. ISSN 0002-7863. PMID 25516157.
  12. ^ Murphy, Vincent J.; Rabinovich, Daniel; Hascall, Tony; Klooster, Wim T.; Koetzle, Thomas F.; Parkin, Gerard (1 May 1998). "False Minima in X-ray Structure Solutions Associated with a "Partial Polar Ambiguity": Single Crystal X-ray and Neutron Diffraction Studies on the Eight-Coordinate Tungsten Hydride Complexes, W(PMe3)4H2X2 (X = F, Cl, Br, I) and W(PMe3)4H2 F(FHF)". Journal of the American Chemical Society. 120 (18): 4372–4387. Bibcode:1998JAChS.120.4372M. doi:10.1021/ja974086g. ISSN 0002-7863.
  13. ^ Zhu, Guang; Parkin, Gerard (1 December 2005). "Synthesis and Structural Characterization of M(PMe3)3(O2CR)2(OH2)H2 (M = Mo, W): Aqua−Hydride Complexes of Molybdenum and Tungsten". Inorganic Chemistry. 44 (26): 9637–9639. doi:10.1021/ic051617q. ISSN 0020-1669. PMID 16363830.
  14. ^ a b c d Sattler, Aaron; Parkin, Gerard (28 January 2010). "Cleaving carbon–carbon bonds by inserting tungsten into unstrained aromatic rings". Nature. 463 (7280): 523–526. Bibcode:2010Natur.463..523S. doi:10.1038/nature08730. ISSN 0028-0836. PMID 20110998.
  15. ^ Green, Malcolm L. H.; Parkin, Gerard (1 January 1986). "Ethylene insertion into the W–C bond of the η2-formaldehyde ligand system of W(PMe3)4(η2-CH2O)H2 giving the oxometallacyclopentane derivative W(OCH2CH2CH2)(PMe3)2(C2H4)2 and related studies". Journal of the Chemical Society, Chemical Communications (1): 90–91. doi:10.1039/C39860000090. ISSN 0022-4936.
  16. ^ Green, Malcolm L. H.; Parkin, Gerard; Moynihan, Kelly J.; Prout, Keith (1 January 1984). "Formation of an η2-formaldehyde compound from methanol and its hydrogenation giving methanol". Journal of the Chemical Society, Chemical Communications (22): 1540. doi:10.1039/C39840001540. ISSN 0022-4936.
  17. ^ a b Filippou, Alexander C.; Weidemann, Nils; Philippopoulos, Athanassios I.; Schnakenburg, Gregor (11 September 2006). "Activation of Aryl Germanium(II) Chlorides by [Mo(PMe3)6] and [W(η2-CH2PMe2)H(PMe3)4]: A New Route to Metal–Germanium Triple Bonds". Angewandte Chemie International Edition. 45 (36): 5987–5991. Bibcode:2006ACIE...45.5987F. doi:10.1002/anie.200602061. ISSN 1433-7851. PMID 16927310.
  18. ^ a b Filippou, Alexander C.; Weidemann, Nils; Schnakenburg, Gregor (21 July 2008). "Tungsten-Mediated Activation of a Pb II N bond: A New Route to Tungsten–Lead Triple Bonds". Angewandte Chemie International Edition. 47 (31): 5799–5802. Bibcode:2008ACIE...47.5799F. doi:10.1002/anie.200801331. ISSN 1433-7851. PMID 18574837.
  19. ^ a b c Rabinovich, Daniel; Parkin, Gerard (December 1995). "Terminal Sulfido, Selenido, and Tellurido Complexes of Tungsten". Inorganic Chemistry. 34 (25): 6341–6361. doi:10.1021/ic00129a021. ISSN 0020-1669.
  20. ^ a b Rabinovich, Daniel; Parkin, Gerard (November 1991). "Synthesis and structure of W(PMe3)4(Te)2: the first transition-metal complex with a terminal tellurido ligand". Journal of the American Chemical Society. 113 (24): 9421–9422. Bibcode:1991JAChS.113.9421R. doi:10.1021/ja00024a088. ISSN 0002-7863.
  21. ^ a b Rabinovich, Daniel; Parkin, Gerard (May 1994). "Syntheses, Structures, and Reactivities of Terminal Selenido Complexes of Tungsten". Inorganic Chemistry. 33 (11): 2313–2314. doi:10.1021/ic00089a001. ISSN 0020-1669.
  22. ^ Rabinovich, Daniel; Parkin, Gerard (July 1991). "The syntheses, structures, and reactivity of monomeric tungsten(IV) and tungsten(VI) bis(sulfido) complexes: facile elimination of hydrogen from hydrogen sulfide". Journal of the American Chemical Society. 113 (15): 5904–5905. Bibcode:1991JAChS.113.5904R. doi:10.1021/ja00015a078. ISSN 0002-7863.
  23. ^ Rabinovich, Daniel; Parkin, Gerard (October 1993). "Isocyanide-induced coupling of terminal tellurido ligands: the synthesis and structure of W(PMe3)(CN-tert-Bu)4(.eta.2-Te2)". Journal of the American Chemical Society. 115 (21): 9822–9823. Bibcode:1993JAChS.115.9822R. doi:10.1021/ja00074a068. ISSN 0002-7863.
  24. ^ a b Sattler, Aaron; Parkin, Gerard (24 February 2011). "Carbon-Sulfur Bond Cleavage and Hydrodesulfurization of Thiophenes by Tungsten". Journal of the American Chemical Society. 133 (11): 3748–3751. doi:10.1021/ja111034g. PMID 21348517.
  25. ^ Rabinovich, Daniel; Zelman, Ross; Parkin, Gerard (December 1990). "Competitive sp3 and sp2 carbon-hydrogen bond activation of phenols by W(PMe3)6 and W(PMe3)4(h2-CH2PMe2)H: formation of four- and five-membered oxametallacycles". Journal of the American Chemical Society. 112 (26): 9632–9633. Bibcode:1990JAChS.112.9632R. doi:10.1021/ja00182a029. ISSN 0002-7863.
  26. ^ Rabinovich, Daniel; Zelman, Ross; Parkin, Gerard (June 1992). "Synthetic, structural, and mechanistic studies of the carbon-hydrogen bond activation of phenols by tungsten complexes W(PMe3)6 and W(PMe3)4(.eta.2-CH2PMe2)H". Journal of the American Chemical Society. 114 (12): 4611–4621. Bibcode:1992JAChS.114.4611R. doi:10.1021/ja00038a025. ISSN 0002-7863.
  27. ^ Buccella, Daniela; Tanski, Joseph M.; Parkin, Gerard (1 July 2007). "Factors Influencing Coordination versus Oxidative Addition of C−H Bonds to Molybdenum and Tungsten: Structural and Spectroscopic Evidence That the Calixarene Framework Promotes C−H Bond Activation". Organometallics. 26 (14): 3275–3278. doi:10.1021/om700279c. ISSN 0276-7333.
  28. ^ Buccella, Daniela; Parkin, Gerard (1 December 2006). "p – tert -Butylcalix[4]arene Complexes of Molybdenum and Tungsten: Reactivity of the Calixarene Methylene CH Bond and the Facile Migration of the Metal around the Phenolic Rim of the Calixarene". Journal of the American Chemical Society. 128 (50): 16358–16364. Bibcode:2006JAChS.12816358B. doi:10.1021/ja066457b. ISSN 0002-7863. PMID 17165791.
  29. ^ Sattler, Aaron; Parkin, Gerard (2 November 2011). "Formation of a cationic alkylidene complex via formal hydride abstraction: synthesis and structural characterization of [W(PMe3)4(η2-CHPMe2)H]X (X = Br, I)". Chemical Communications. 47 (48): 12828–12830. doi:10.1039/C1CC15457E. PMID 22048609.
  30. ^ Andrae, D.; Häußermann, U.; Dolg, M.; Stoll, H.; Preuß, H. (1990). "Energy-adjustedab initio pseudopotentials for the second and third row transition elements". Theoretica Chimica Acta. 77 (2): 123–141. doi:10.1007/BF01114537. ISSN 0040-5744.
  31. ^ a b c d e Miscione, Gian Pietro; Carvajal, Maria Angels; Bottoni, Andrea (26 September 2011). "Aromatic Carbon–Carbon Bond Cleavage Using Tungsten Complexes. A DFT Computational Study". Organometallics. 30 (18): 4924–4934. doi:10.1021/om2005029. ISSN 0276-7333.
  32. ^ a b c Liu, Yuxia; Zhang, Dongju; Gao, Jun; Liu, Chengbu (26 November 2012). "Theoretical Elucidation of the Mechanism of Cleavage of the Aromatic CC Bond in Quinoxaline by a Tungsten-Based Complex [W(PMe 3 ) 4 (η 2 -CH 2 PMe 2 )H]". Chemistry – A European Journal. 18 (48): 15537–15545. doi:10.1002/chem.201200093. ISSN 0947-6539. PMID 23055438.
  33. ^ Li, Jun; Yoshizawa, Kazunari (16 January 2012). "Mechanistic Insight into the Cleavage of an Aromatic CC Bond by Tungsten". Chemistry – A European Journal. 18 (3): 783–787. Bibcode:2012ChEuJ..18..783L. doi:10.1002/chem.201101899. ISSN 0947-6539. PMID 22170350.
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