Syntheses, Crystal Structures and Reactivity of Organometallic Tantalum(IV) Phosphinidene Complexes: trans-[{Cp*TaCl(μ-PR)}2] (Cp* = C5Me5, R = Cy, tBu, Ph), cis- and trans-[{Cp*TaCl(μ-PMes)}2] (Mes = 2,4,6-Me3C6H2) and cis-[{Cp′TaCl(μ-PMes)}2] (Cp′ = C5H4Me)

Addition of Primary and Secondary Phosphines to Dinuclear Tantalum Hydrides: Synthesis of Phosphides and Phosphinidenes via P−H Bond Activation

“…While the three peaks showed coupling patterns similar to those observed for the tantalum phosphides, the resonance at approximately 450 ppm suggested the presence of a phosphinidene. The 31 P chemical shifts for the trans -bis(phosphinidene) tantalum complexes [Cp*TaCl(μ-PR)] 2 are at 437.6, 482.0, 403.9, and 390.3 ppm for R = Cy, t Bu, Ph, and Mes, respectively. , In the 1 H NMR spectrum, the observation of a single peak at 10.9 ppm integrating to two equivalent hydrides supports the synthesis of ( PhPh [NPN]Ta) 2 (μ-H) 2 (μ-PCy), 5a . Further NMR studies and elemental analysis confirmed this formulation.…”

Addition of Primary and Secondary Phosphines to Dinuclear Tantalum Hydrides: Synthesis of Phosphides and Phosphinidenes via P−H Bond Activation

“…While the three peaks showed coupling patterns similar to those observed for the tantalum phosphides, the resonance at approximately 450 ppm suggested the presence of a phosphinidene. The 31 P chemical shifts for the trans -bis(phosphinidene) tantalum complexes [Cp*TaCl(μ-PR)] 2 are at 437.6, 482.0, 403.9, and 390.3 ppm for R = Cy, t Bu, Ph, and Mes, respectively. , In the 1 H NMR spectrum, the observation of a single peak at 10.9 ppm integrating to two equivalent hydrides supports the synthesis of ( PhPh [NPN]Ta) 2 (μ-H) 2 (μ-PCy), 5a . Further NMR studies and elemental analysis confirmed this formulation.…”

Phosphinidene-bridged binuclear complexes

“…A final example of this approach was reported by Hey-Hawkins and co-workers, who prepared several ditantalum bis(phosphinidene) complexes in high yield (73- [30]. We note that the role of the lithium reagent in these reactions is multiple, since it acts as reducing agent, base and substitution reagent.…”

“…The reaction of the ditantalum complex 22c with an excess (50-fold) of wet acetone gives the trinuclear oxo complex 162 in very low yield (Scheme 79) [30]. The presence of the phosphinidene-derived phenylphosphinate group in the latter compound was confirmed through a single-crystal X-ray diffraction analysis, although no signals were detected in the 31 P NMR spectrum to confirm the presence of the PH proton.…”

“…All these complexes have Sc-P bond lengths in the range 2. 41 Significant structural data are also available for an extensive family of dinuclear tantalum complexes reported by the groups of Hey-Hawkins [30,44] and Fryzuk [46]. All these complexes display trigonal planar geometry around the P atoms, with relatively short Ta-P lengths (av.…”

Imidazoliumyl-substituted di- and iso-tetraphosphanes and their metal-mediated fragmentation reactions

“…32 Only a few related complexes have been reported, which feature a similar diphosphene ligand bridging two transition-metal atoms, such as Fe, Mo and Ta. 29,30,33,34 The Pd-Pd distance of 3.8007(8) Å is signicantly larger than the sum of the van der Waals radii (3.26 Å), 35 indicating that there is no signicant Pd/Pd interaction in 8 2+ .…”

Addition of Primary and Secondary Phosphines to Dinuclear Tantalum Hydrides: Synthesis of Phosphides and Phosphinidenes via P−H Bond Activation

“…While the three peaks showed coupling patterns similar to those observed for the tantalum phosphides, the resonance at approximately 450 ppm suggested the presence of a phosphinidene. The 31 P chemical shifts for the trans -bis(phosphinidene) tantalum complexes [Cp*TaCl(μ-PR)] 2 are at 437.6, 482.0, 403.9, and 390.3 ppm for R = Cy, t Bu, Ph, and Mes, respectively. , In the 1 H NMR spectrum, the observation of a single peak at 10.9 ppm integrating to two equivalent hydrides supports the synthesis of ( PhPh [NPN]Ta) 2 (μ-H) 2 (μ-PCy), 5a . Further NMR studies and elemental analysis confirmed this formulation.…”

Phosphinidene-bridged binuclear complexes

“…A final example of this approach was reported by Hey-Hawkins and co-workers, who prepared several ditantalum bis(phosphinidene) complexes in high yield (73- [30]. We note that the role of the lithium reagent in these reactions is multiple, since it acts as reducing agent, base and substitution reagent.…”

“…The reaction of the ditantalum complex 22c with an excess (50-fold) of wet acetone gives the trinuclear oxo complex 162 in very low yield (Scheme 79) [30]. The presence of the phosphinidene-derived phenylphosphinate group in the latter compound was confirmed through a single-crystal X-ray diffraction analysis, although no signals were detected in the 31 P NMR spectrum to confirm the presence of the PH proton.…”

“…All these complexes have Sc-P bond lengths in the range 2. 41 Significant structural data are also available for an extensive family of dinuclear tantalum complexes reported by the groups of Hey-Hawkins [30,44] and Fryzuk [46]. All these complexes display trigonal planar geometry around the P atoms, with relatively short Ta-P lengths (av.…”

Imidazoliumyl-substituted di- and iso-tetraphosphanes and their metal-mediated fragmentation reactions

“…32 Only a few related complexes have been reported, which feature a similar diphosphene ligand bridging two transition-metal atoms, such as Fe, Mo and Ta. 29,30,33,34 The Pd-Pd distance of 3.8007(8) Å is signicantly larger than the sum of the van der Waals radii (3.26 Å), 35 indicating that there is no signicant Pd/Pd interaction in 8 2+ .…”

Addition of Primary and Secondary Phosphines to Dinuclear Tantalum Hydrides: Synthesis of Phosphides and Phosphinidenes via P−H Bond Activation

“…While the three peaks showed coupling patterns similar to those observed for the tantalum phosphides, the resonance at approximately 450 ppm suggested the presence of a phosphinidene. The 31 P chemical shifts for the trans -bis(phosphinidene) tantalum complexes [Cp*TaCl(μ-PR)] 2 are at 437.6, 482.0, 403.9, and 390.3 ppm for R = Cy, t Bu, Ph, and Mes, respectively. , In the 1 H NMR spectrum, the observation of a single peak at 10.9 ppm integrating to two equivalent hydrides supports the synthesis of ( PhPh [NPN]Ta) 2 (μ-H) 2 (μ-PCy), 5a . Further NMR studies and elemental analysis confirmed this formulation.…”

Phosphinidene-bridged binuclear complexes

“…A final example of this approach was reported by Hey-Hawkins and co-workers, who prepared several ditantalum bis(phosphinidene) complexes in high yield (73- [30]. We note that the role of the lithium reagent in these reactions is multiple, since it acts as reducing agent, base and substitution reagent.…”

“…The reaction of the ditantalum complex 22c with an excess (50-fold) of wet acetone gives the trinuclear oxo complex 162 in very low yield (Scheme 79) [30]. The presence of the phosphinidene-derived phenylphosphinate group in the latter compound was confirmed through a single-crystal X-ray diffraction analysis, although no signals were detected in the 31 P NMR spectrum to confirm the presence of the PH proton.…”

“…All these complexes have Sc-P bond lengths in the range 2. 41 Significant structural data are also available for an extensive family of dinuclear tantalum complexes reported by the groups of Hey-Hawkins [30,44] and Fryzuk [46]. All these complexes display trigonal planar geometry around the P atoms, with relatively short Ta-P lengths (av.…”

Imidazoliumyl-substituted di- and iso-tetraphosphanes and their metal-mediated fragmentation reactions

“…32 Only a few related complexes have been reported, which feature a similar diphosphene ligand bridging two transition-metal atoms, such as Fe, Mo and Ta. 29,30,33,34 The Pd-Pd distance of 3.8007(8) Å is signicantly larger than the sum of the van der Waals radii (3.26 Å), 35 indicating that there is no signicant Pd/Pd interaction in 8 2+ .…”