The detection and characterization of surface immobilized phosphine ligands and transition metal catalysts by high resolution 31P solid state NMR using magic angle spinning techniques

Bemi, L.; Clark, H. C.; Davies, Julian A.; Drexler, Dóra; Fyfe, C. A.; Wasylishen, Roderick E.

doi:10.1016/s0022-328x(00)82572-3

Cited by 31 publications

(6 citation statements)

References 16 publications

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“…The line widths of the signals for the surface-bound complexes on TiO 2 were somewhat larger (in case of 4) or similar (in case of 7) as those for the pure crystalline complexes whereas the NP-TiO 2 -supported complexes displayed an increase in linewidths by nearly an order of magnitude (Figure 1). Similar effects have repeatedly been observed for surface-bound phosphane complexes [21,22] and also for the phosphane oxide derived from 6 but not for ligand 6 itself nor its complex 5. [11] The major contribution to this broadening is presumably a substantial chemical shift dispersion which arises as a consequence of disordered surface environments.…”

Section: Resultssupporting

confidence: 79%

On the Immobilisation of Catechol Phosphane Palladium Complexes on Titania

2008

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Two isomeric bis(phosphane) palladium chloride complexes with functional catechol phosphane ligands were immobilised on different specimens of TiO 2 . The solid materials were characterised by 31 P NMR spectroscopy both when dry and as suspensions in various solvents. The NMR spectroscopic studies demonstrated that the resistance towards leaching varies strongly with the nature of the carrier material and

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Section: Resultssupporting

confidence: 79%

On the Immobilisation of Catechol Phosphane Palladium Complexes on Titania

2008

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“…Such chemical shift differences between the solid-state CP/MAS and solution NMR data have been observed for other compounds, including tertiary phosphines and their transition metal complexes. [25][26][27][28][29][30][31][32] Differences of e 5-6 ppm are common, and the compounds are still considered to possess similar structures in solution and in the solid state, at least qualitatively. [25][26][27][28][29][30][31][32] Larger chemical shift differences are often considered a manifestation of major structural differences.…”

Section: Resultsmentioning

confidence: 99%

Characterization of Five-Coordinate Ruthenium(II) Phosphine Complexes by X-ray Diffraction and Solid-State³¹P CP/MAS NMR Studies and Their Reactivity with Sulfoxides and Thioethers

et al. 1996

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31P CP/MAS NMR spectroscopy is examined as a method of characterization for ruthenium(II) phosphine complexes in the solid state, and the results are compared with X-ray crystallographic data determined for RuCl(2)(dppb)(PPh(3)) (dppb = Ph(2)P(CH(2))(4)PPh(2)), RuBr(2)(PPh(3))(3), and the previously determined RuCl(2)(PPh(3))(3). Crystals of RuBr(2)(PPh(3))(3) (C(54)H(45)Br(2)P(3)Ru) are monoclinic, space group P2(1)/a, with a = 12.482(4) Å, b = 20.206(6) Å, c = 17.956(3) Å, beta = 90.40(2) degrees, and Z = 4, and those of RuCl(2)(dppb)(PPh(3)) (C(46)H(43)Cl(2)P(3)Ru) are also monoclinic, space group P2(1)/n, with a = 10.885(2) Å, b = 20.477(1) Å, c = 18.292(2) Å, beta = 99.979(9) degrees, and Z = 4. The structure of RuBr(2)(PPh(3))(3) was solved by direct methods, and that of RuCl(2)(dppb)(PPh(3)) was solved by the Patterson method. The structures were refined by full-matrix least-squares procedures to R = 0.048 and 0.031 (R(w) = 0.046 and 0.032) for 5069 and 5925 reflections with I >/= 3sigma(I), respectively. Synthetic routes to RuBr(2)(dppb)(PPh(3)) and [RuBr(dppb)](2)(&mgr;(2)-dppb) are reported. The reactivity of RuCl(2)(dppb)(PPh(3)) with the neutral two-electron donor ligands (L) dimethyl sulfoxide, tetramethylene sulfoxide, tetrahydrothiophene, and dimethyl sulfide to give [(L)(dppb)Ru(&mgr;-Cl)(3)RuCl(dppb)] is discussed.

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“…Note that in the solid-state chemical and magnetic equivalence are not synonyms. Fyfe and co-workers 14 described the 31 P solution spectrum of dppm where only one signal was observed at δ -23, but in the solid state two signals are expected in the 31 P CP MAS spectrum of crystalline dppm. According to the crystallographic structure one entire molecule is present in the asymmetric unit (orthorhombic space group Pbca Z = 8) and the two P atoms are crystallographically inequivalent.…”

Section: Raman Spectroscopymentioning

confidence: 99%

“…The use of solid-state NMR techniques in addition to complementary vibrational measurements can be helpful in providing information about the structure and interactions between molecules and substrates. [11][12][13] Work by Fyfe and co-workers 14 describes the use of 31 P MAS NMR spectroscopy for the study of phosphine complexes immobilized onto silica gel, in order to overcome the disadvantages in the characterization of such systems.…”

Section: Introductionmentioning

confidence: 99%

Properties of [Pd2X2(dppm)2] (X = Cl, SnCl3, dppm = Bis(diphenylphosphino)methane) complexes on porous vycor glass

Gimenez¹,

Alves²

2004

J. Braz. Chem. Soc.

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Neste trabalho o vidro poroso Vycor foi utilizado como matriz para a imobilização de complexos contendo ligação metal-metal [Pd 2 Cl 2 (dppm) 2 ], [Pd 2 (SnCl 3 )Cl(dppm) 2 ] e [Pd 2 (SnCl 3 ) 2 (dppm) 2 ] A elevada reatividade das ligações metal-metal em reações de inserção de moléculas como CO e SO 2 é preservada no meio poroso, sendo reversível sob vácuo. Os espectros de RMN MAS 31 P, refletância difusa no infravermelho e Raman indicaram que há uma gama de interações possíveis entre o vidro e as moléculas, como resultado da disponibilidade de diferentes grupamentos presentes nas moléculas, bem como de uma topologia porosa irregular. O caráter estático das moléculas no ambiente restrito impede movimentos do anel Pd 2 P 4 C 2 entre as conformações barco e cadeira, de modo que as moléculas confinadas podem ter diferentes conformações.Porous Vycor glass (PVG) is used as a matrix for immobilization of complexes containing metal-metal bonds: [Pd 2 Cl 2 (dppm) 2 ], [Pd 2 (SnCl 3 )Cl(dppm) 2 ] and [Pd 2 (SnCl 3 ) 2 (dppm) 2 ]. The high reactivity of the metal-metal bonds in insertion reactions with small molecules such as CO and SO 2 is preserved in the pore medium, and is reversible under vacuum.31 P MAS-NMR and Raman spectra indicate that there is a range of interactions between the glass and the adsorbed molecules as a result of the availability of different groups in the molecules and of the irregular pore topology as well. The static character of the molecules in the restrictive pore environment precludes motions such as flipping of the ring Pd 2 P 4 C 2 between boat and chair conformations and rotation of the phenyl rings, and the molecules may present a range of conformations.Keywords: palladium complexes, Vycor, immobilization, 31 P NMR, Raman, metal-metal bond IntroductionMany adsorption studies related to organometallic compounds and transition metal complexes on porous glasses have been performed with the purpose of applications such as catalysis 1,2 and formation of nanoparticles by thermal decomposition or photolysis of the molecular species. [3][4][5][6][7] In this area, a number of papers describe the immobilization of carbonyl complexes of iron 3-7 and ruthenium 8-10 onto porous glasses, since these complexes are good precursors to metallic or oxide particles via thermal and photochemical decomposition.Immobilization studies of transition metal phosphine complexes were limited for many years by the lack of suitable characterization techniques. Infrared spectroscopy is very useful in the characterization of carbonyl complexes embedded in porous glasses, giving however spectra dominated by the silica matrix bands in the case of phosphine complexes. The use of solid-state NMR techniques in addition to complementary vibrational measurements can be helpful in providing information about the structure and interactions between molecules and substrates. 15 These compounds take part in different types of reactions, such as additions, substitutions and insertions, owing to the presence of a single metal-metal b...

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The detection and characterization of surface immobilized phosphine ligands and transition metal catalysts by high resolution 31P solid state NMR using magic angle spinning techniques

Cited by 31 publications

References 16 publications

On the Immobilisation of Catechol Phosphane Palladium Complexes on Titania

On the Immobilisation of Catechol Phosphane Palladium Complexes on Titania

Characterization of Five-Coordinate Ruthenium(II) Phosphine Complexes by X-ray Diffraction and Solid-State³¹P CP/MAS NMR Studies and Their Reactivity with Sulfoxides and Thioethers

Properties of [Pd2X2(dppm)2] (X = Cl, SnCl3, dppm = Bis(diphenylphosphino)methane) complexes on porous vycor glass

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The detection and characterization of surface immobilized phosphine ligands and transition metal catalysts by high resolution 31P solid state NMR using magic angle spinning techniques

Cited by 31 publications

References 16 publications

On the Immobilisation of Catechol Phosphane Palladium Complexes on Titania

On the Immobilisation of Catechol Phosphane Palladium Complexes on Titania

Characterization of Five-Coordinate Ruthenium(II) Phosphine Complexes by X-ray Diffraction and Solid-State31P CP/MAS NMR Studies and Their Reactivity with Sulfoxides and Thioethers

Properties of [Pd2X2(dppm)2] (X = Cl, SnCl3, dppm = Bis(diphenylphosphino)methane) complexes on porous vycor glass

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Characterization of Five-Coordinate Ruthenium(II) Phosphine Complexes by X-ray Diffraction and Solid-State³¹P CP/MAS NMR Studies and Their Reactivity with Sulfoxides and Thioethers