Multinuclear NMR study of the complexation of d-galactaric and d-mannaric acids with molybdenum(VI)

Ramos, M. Luísa; Caldeira, M.Madalena; Gil, Victor M. S.; Bekkum, H. van; Peters, Joop A.

doi:10.1016/0277-5387(94)80004-9

Cited by 27 publications

(15 citation statements)

References 22 publications

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“…The 13 C spectra were recorded using proton decoupling techniques (Waltz-16) taking advantage of the nuclear Overhauser effect. 43,44 Computational Details 95 Mo and 183 W NMR spectra were obtained using, as external references, the signals of the tetrahedral MoO 4 2and WO 4 2in solutions of Na 2 MoO 4 and Na 2 WoO 4 , 2 mol dm -3 , pH values of dissolution, 9.0 and 9.8, respectively (δ = 0).…”

Section: Nmr Experimentsmentioning

confidence: 99%

Oxocomplexes of Mo(vi) and W(vi) with 8-hydroxyquinoline-5-sulfonate in solution: structural studies and the effect of the metal ion on the photophysical behaviour

et al. 2015

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Multinuclear ((1)H, (13)C, (95)Mo and (183)W) NMR spectroscopy, combined with DFT calculations, provides detailed information on the complexation between the Mo(VI) and W(VI) oxoions and 8-hydroxyquinoline-5-sulfonate (8-HQS) in aqueous solution. Over the concentration region studied, Mo(VI) and W(VI) oxoions form three homologous complexes with 8-HQS in water in the pH range 2-8. Two of these, detected at pH < 6, are mononuclear 1 : 2 (metal : ligand) isomers, with the metal centre (MO2(2+)) coordinated to two 8-HQS ligands. An additional complex, dominant at slightly higher pH values (5-8) for solutions with a 1 : 1 metal : ligand molar ratio, has a binuclear M2O5(2+) centre coordinated to two 8-HQS ligands. The two metal atoms are bridged by three oxygen atoms, two coming from 8-HQS, together with the M-O-M bridge of the bimetallic centre. We show that the long-range exchange corrected BOP functional with local response dispersion (LCBOPLRD), together with explicit solvent molecules, leads to geometries that readily converge to equilibrium structures having realistic bridging O8-HQS-M bonds. Previous attempts to calculate the structures of such binuclear complexes using DFT with the B3LYP functional have failed due to difficulties in treating the weak interaction in these bridged structures. We believe that the LCBOPLRD method may be of more general application in theoretical studies in related binuclear metal complexes. UV/visible absorption and luminescence spectra of all the complexes have also been recorded. The complex between Mo(vi) and 8-HQS is only weakly luminescent, in contrast to what has been observed with this ligand and many other metal ions. We suggest that this is due to the presence of low-lying ligand-to-metal charge transfer (LMCT) states close to the emitting ligand-based level which quench the emission. However, with W(VI), DFT calculations show that the LMCT states are now much higher in energy than the ligand based levels, leading to a marked increase in fluorescence.

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Section: Nmr Experimentsmentioning

confidence: 99%

Oxocomplexes of Mo(vi) and W(vi) with 8-hydroxyquinoline-5-sulfonate in solution: structural studies and the effect of the metal ion on the photophysical behaviour

et al. 2015

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“…[17][18][19] In addition, the aromatic portion of aroyl hydrazones is good candidates for spacer part of organic-inorganic materials, because not only they can act as hydrogen bond acceptors or donors, but can also provide identification sites for π-π stacking interactions as appealing supramolecular structure when coordinating to the metal ions. Moreover, hydrazones and their coordination complexes have attracted a lot of research attention because of their various applications such as molecular sensors , [20] catalysts, [21,22] magnetic properties, [23] and a wide spectrum of biological activities (antimicrobial, [24,25] anti-cariogenic, [26] anticonvulsant, [27] antitubercular and anticancer, [28,29] anti-inflammatory [30] ). Recently, ligands of hydrazone type and their metal complexes have been synthesized which studied by DFT calculations and Hirshfeld surface analysis.…”

Section: Introductionmentioning

confidence: 99%

A new supramolecular zinc(II) complex containing 4‐biphenylcarbaldehyde isonicotinoylhydrazone ligand: Nanostructure synthesis, catalytic activities and Hirshfeld surface analysis

Tyula

Zabardasti

Goudarziafshar³

et al. 2017

Applied Organom Chemis

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A new potentially tridentate hydrazone ligand, 4‐biphenylcarbaldehyde isonicotinoylhydrazone (4‐bpinh), was prepared by the condensation of biphenyl‐4‐carboxaldehyde with isonicotinic acid hydrazide. Then, its nano‐sized and single crystal of zinc complex were synthesized using sonochemical and heat gradient methods, respectively. The structure of complex, [Zn(4‐bpinh)2 Br2] (1), was determined by single‐crystal X‐ray diffraction, FT‐IR, and elemental analysis, and the nano‐structure of complex was characterized by FT‐IR, XRD, and SEM. The single crystal X‐ray structure of complex showed that the metal center has a distorted tetrahedral geometry and the hydrazone ligand acts as monodentate trough the pyridyl N atom. Moreover, the analysis of crystal structures indicates the existence of intermolecular interactions such as N/C–H⋯Br/O, N/C–H⋯π, and π⋯π stacking in the stabilization of complex structure which finally led to the formation of the three‐dimensional supramolecular structure. Also, the impact of this interactions was more studied using Hirshfeld surface analysis and corresponding 2D fingerprint plots. Furthermore, the catalytic activity of 1 was studied in the selective oxidation of various sulfides to corresponding sulfoxides using hydrogen peroxide as the oxidative agent.

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“…The detailed conditions can be found in previous papers. [5][6][7][8] The 2D NMR spectra, DQFCOSY, 9 HET-COR 10 and COLOC, 11 were recorded on a Varian Unity-500 NMR spectrometer. The 31 P spectra were obtained on a Varian Unity-500 NMR spectrometer, using H 3 PO 4 (85%) as external reference, sw = 25,000 Hz, at = 1.0 s and d 1 = 5.0 s.…”

Section: Methodsmentioning

confidence: 99%

“…[4][5][6][7][8][17][18][19][20][21] The oxygen shifts are typical of terminal M@O groups, and there is no evidence for any bridging oxygen atoms. 4,[6][7][8][17][18][19][22][23][24][25][26] The high frequency shifts observed for the carboxylic and the adjacent carbinol C nuclei are characteristic of the involvement of these groups in complexation; [4][5][6][7][8][17][18][19]21,27-33 the other carbon shifts upon complexation are much smaller. Accordingly, only the proton H-2 undergoes a significant chemical shift change to high frequency.…”

Section: :2 (Metal-ligand) Complexesmentioning

confidence: 99%

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Multinuclear NMR study of the complexes of 6-phospho-d-gluconic acid with W(VI) and Mo(VI)

Ramos

Gil

2004

Carbohydrate Research

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Abstract-Multinuclear ( 1 H, 13 C, 17 O, 31 P, 95 Mo, 183 W) magnetic resonance spectroscopy (1D and 2D) has been used to show that 6-phospho-D D-gluconic acid forms three complexes with tungsten(VI) and six complexes with molybdenum(VI) in aqueous solution, depending on pH and concentration. Two isomeric 1:2 (metal-ligand) complexes are detected both with tungstate(VI) and molybdate(VI), having MO 2 2+ centres and involving the carboxylate and the adjacent OH groups in addition to one 2:1 (metal-ligand) complex possessing a M 2 O 5 2+ centre, with the ligand being coordinated by the carboxylate group and the three consecutive OH groups in positions 2, 3 and 4. Molybdate(VI) forms three additional species, which are not detected with tungstate. One of them is a 2:1 complex with a Mo 2 O 5 2+ centre, with the ligand being tetradentate via O-3, O-4, O-5 and the phosphate group. The other two are 12:4 species, which can be seen as two 1:2 complexes bound together in a ring through two diphosphomolybdate moieties each derived from heptamolybdate by inclusion of two phosphate groups from the ligands.

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Multinuclear NMR study of the complexation of d-galactaric and d-mannaric acids with molybdenum(VI)

Cited by 27 publications

References 22 publications

Oxocomplexes of Mo(vi) and W(vi) with 8-hydroxyquinoline-5-sulfonate in solution: structural studies and the effect of the metal ion on the photophysical behaviour

Oxocomplexes of Mo(vi) and W(vi) with 8-hydroxyquinoline-5-sulfonate in solution: structural studies and the effect of the metal ion on the photophysical behaviour

A new supramolecular zinc(II) complex containing 4‐biphenylcarbaldehyde isonicotinoylhydrazone ligand: Nanostructure synthesis, catalytic activities and Hirshfeld surface analysis

Multinuclear NMR study of the complexes of 6-phospho-d-gluconic acid with W(VI) and Mo(VI)

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