<sup>61</sup>Ni NMR spectroscopy of di‐ and tricarbonylnickel complexes

Behringer, Klaus D.; Blümel, Janet

doi:10.1002/mrc.1260330907

Cited by 26 publications

(33 citation statements)

References 24 publications

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“…Representative procedure for the oxidation of tetrahydrothiophene (THT) to the sulfoxide: 17.6 mg (0.2 mmol) of THT and 0.1 mmol of the respective adduct were weighed into a 5 mm NMR tube and dissolved in 0.5 mL of C 6 D 6 inside a glove box. The tube was then sealed with a glass stopper lubricated with silicone grease. 1 H and 13 C NMR spectra of the sample were recorded at room temperature every 30 min until the oxidation was complete.…”

Section: Methodsmentioning

confidence: 99%

Di(hydroperoxy)alkane Adducts of Phosphine Oxides: Safe, Solid, Stoichiometric, and Soluble Oxidizing Agents

Ahn

Bhuvanesh

Blümel

2017

Chemistry A European J

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The di(hydroperoxy)alkane adducts of phosphine oxides 1-9, Ph PO⋅(HOO) CMe , Cy PO⋅(HOO) CMe , Ph PO⋅ (HOO) CMeEt, Cy PO⋅(HOO) CMeEt, Cy PO⋅(HOO) CEt , Cy PO⋅ (HOO) C(CH ) , Cy PO⋅(HOO) CMePh, (Ph P(O)CH CH P(O)Ph )⋅ ((HOO) CEt ) , and Ph P(O)CH P(O)Ph ⋅(HOO) CMe , respectively, are synthesized and fully characterized by H, C, and P NMR, and IR spectroscopies. Single crystal X-ray structures are reported for 3-9. Different one-pot synthetic pathways, starting from R P, R PO, R PO⋅H O, and R PO⋅H O are explored and discussed and a mechanism for the formation of the di(hydroperoxy)alkane adducts of phosphine oxides is suggested. The longevity of the adducts is tested by monitoring the oxidation of Ph P with quantitative NMR. The solubilities of the adducts in organic solvents are presented, and their applicability as stoichiometric oxidizing agents for the selective oxidation of sulfides to sulfoxides is reported.

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Section: Methodsmentioning

confidence: 99%

Di(hydroperoxy)alkane Adducts of Phosphine Oxides: Safe, Solid, Stoichiometric, and Soluble Oxidizing Agents

Ahn

Bhuvanesh

Blümel

2017

Chemistry A European J

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“…Furthermore their analytical data, for example even d( values can be obtained. [52] In order to avoid the toxic Ni(CO) 4 for the preparation of the carbonylnickel compounds, [52] we apply two routes (Scheme 3). In the first route (COD) 2 Ni is treated with the phosphine, e.g., 7, and 20 forms, as one COD ligand is replaced.…”

Section: Synthesis Of the Nickel Catalystsmentioning

confidence: 99%

“…Carbonylnickel complexes in particular have the advantage that they are cheap, easily prepared, and good for analytical purposes, because they are not paramagnetic, which can, e.g., be demonstrated by their 61 Ni NMR data. [52] The carbonylnickel complexes are well-defined, and they need no cocatalyst for the cyclotrimerizations. Although they are known to oligomerize or polymerize a variety of different acetylenes, depending on the reaction conditions, [53] for our detailed and systematic study phenylacetylene as the substrate is suited best.…”

Section: Introductionmentioning

confidence: 99%

New Silica‐Immobilized Nickel Catalysts for Cyclotrimerizations of Acetylenes

Reinhard¹,

Šoba²,

Röminger³

et al. 2003

Adv Synth Catal

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New dicarbonylnickel catalysts with a variety of mono-and bidentate phosphine ligands, such as Ph 2 P(CH 2 ) x PPh(CH 2 ) y Si(OEt) 3 (x 2, 3; y 2, 3), have been synthesized and fully characterized, three of them by X-ray analyses. All the catalysts have been immobilized on silica by reaction of the ethoxysilane or hydroxy groups of the phosphine linkers with the surface silanol groups. The clean immobilization was proved by 31 P solid-state NMR. It has been demonstrated that the C À O À Si bridge, in contrast to the strong Si À O À Si bond, is easily cleaved by organic solvents and water. With respect to the cyclotrimerization of phenylacetylene the optimal reaction conditions for all molecular and immobilized catalysts have been determined. Cyclooctane was the best solvent, and the optimal reaction temperature was 100 8C for reactions in homogeneous phase, and 155 8C for surface-bound catalysts. The bite angles and spacer lengths of the chelating ligands did not play a major role for the performance of the homogeneous or immobilized catalysts. The latter could be recycled for 12 times, with final substrate conversions still typically between 30 and 40%, and turnover numbers (TON) around 1500. With an excess of substrate in one run a TON of 4810 was obtained for an immobilized carbonylnickel complex with a dppp-type chelate phosphine (x 3, y 2). Reduction of the surface coverage generally resulted in catalysts with longer lifetimes, for example, reduction to one fourth gave a record TON of 7616 for this catalyst. The selectivities of the catalysts all followed one trend. The main products were the cyclotrimers 1,2,4-and 1,3,5-triphenylbenzene, besides dimers, linear trimers and tetramers as side-products. The fraction of the latter decreased at higher temperatures with homogeneous catalysts, and vanished entirely after a few cycles with the immobilized catalysts. On recycling, the initial ratio of unsymmetrical to symmetrical cyclotrimers of typically 5 : 1 gradually changed to about 1 : 1 for all catalysts.

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“…[21] It has a high natural abundance of 99.635 % and a receptivity of 5.69 relative to that of 13 C, while the nuclear quadrupole moment Q of this spin-1 nucleus is rather small (0.0199 10 À28 m 2 ). [21] Hence, unlike, for example, 61 Ni, [26] no special probehead is needed for the 14 N measurement and any conventional liquids NMR spectrometer equipped with a multinuclear probehead can be used. One can pulse quickly with 200 ms relaxation delays (relaxation of the electronics actually seems to be the limiting factor) and spectra of neat organic liquids, such as the solvents CH 3 NO 2 , CH 3 CN, or pyridine, can be obtained within a few minutes.…”

Section: Introductionmentioning

confidence: 99%

¹⁴N NMR and Two‐Dimensional Suspension ¹H and ¹³C HRMAS NMR Spectroscopy of Ionic Liquids Immobilized on Silica

Brenna

Posset

Furrer

et al. 2006

Chemistry A European J

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A variety of popular ionic liquids have been synthesized and characterized, including by optimized (14)N NMR spectroscopy of the neat and dissolved ionic liquids. Ionic liquids incorporating Si(OEt)(3) groups have been immobilized on silica in a well-defined manner with the imidazolium moiety remaining intact. This has been proved by optimized one- and two-dimensional (1)H and (13)C HRMAS NMR spectroscopy of the materials suspended in suitable solvents.

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⁶¹Ni NMR spectroscopy of di‐ and tricarbonylnickel complexes

Cited by 26 publications

References 24 publications

Di(hydroperoxy)alkane Adducts of Phosphine Oxides: Safe, Solid, Stoichiometric, and Soluble Oxidizing Agents

Di(hydroperoxy)alkane Adducts of Phosphine Oxides: Safe, Solid, Stoichiometric, and Soluble Oxidizing Agents

New Silica‐Immobilized Nickel Catalysts for Cyclotrimerizations of Acetylenes

¹⁴N NMR and Two‐Dimensional Suspension ¹H and ¹³C HRMAS NMR Spectroscopy of Ionic Liquids Immobilized on Silica

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61Ni NMR spectroscopy of di‐ and tricarbonylnickel complexes

Cited by 26 publications

References 24 publications

Di(hydroperoxy)alkane Adducts of Phosphine Oxides: Safe, Solid, Stoichiometric, and Soluble Oxidizing Agents

Di(hydroperoxy)alkane Adducts of Phosphine Oxides: Safe, Solid, Stoichiometric, and Soluble Oxidizing Agents

New Silica‐Immobilized Nickel Catalysts for Cyclotrimerizations of Acetylenes

14N NMR and Two‐Dimensional Suspension 1H and 13C HRMAS NMR Spectroscopy of Ionic Liquids Immobilized on Silica

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⁶¹Ni NMR spectroscopy of di‐ and tricarbonylnickel complexes

¹⁴N NMR and Two‐Dimensional Suspension ¹H and ¹³C HRMAS NMR Spectroscopy of Ionic Liquids Immobilized on Silica