Aluminum complexes in solution as studied by aluminum-27. Nuclear magnetic resonance

Haraguchi, Hiroki; Fujiwara, Shizuo

doi:10.1021/j100844a056

Cited by 110 publications

(40 citation statements)

References 5 publications

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“…Crude cell sap of the roots gave a similar chemical shift of 27 Al as that in intact tissues (Fig. 4C), suggesting that the Al form in the intact roots and in their cell sap was the same and that the Al was in a hexacoordinated complex (Haraguchi and Fujiwara, 1969). The chemical shift of major signal in the roots was similar to that observed in the leaves (Ma et al, 1997b).…”

Section: Resultssupporting

confidence: 54%

High Aluminum Resistance in Buckwheat1

1998

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Buckwheat (Fagopyrum esculentum Moench. cv Jianxi), which shows high Al resistance, accumulates Al in the leaves. The internal detoxification mechanism was studied by purifying and identifying Al complexes in the leaves and roots. About 90% of Al accumulated in the leaves was found in the cell sap, in which the dominant organic acid was oxalic acid. Purification of the Al complex in the cell sap of leaves by molecular-sieve chromatography resulted in a complex with a ratio of Al to oxalic acid of 1:3. A 13 C-nuclear magnetic resonance study of the purified cell sap revealed only one signal at a chemical shift 164.4 ppm, which was assigned to the Al-chelated carboxylic group of oxalic acid. A 27 Al-nuclear magnetic resonance analysis revealed one major signal at the chemical shift of 16.0 to 17.0 ppm, with a minor signal at the chemical shift of 11.0 to 12 ppm in both the intact roots and their cell sap, which is consistent with the Al-oxalate complexes at 1:3 and 1:2 ratios, respectively. The purified cell sap was not phytotoxic to root elongation in corn (Zea mays). All of these results indicate that Al tolerance in the roots and leaves of buckwheat is achieved by the formation of a nonphytotoxic Al-oxalate (1:3) complex.

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Section: Resultssupporting

confidence: 54%

High Aluminum Resistance in Buckwheat1

1998

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“…In the case of the Al (III) tanned leather the NMR properties of the 27 Al isotope (100% natural abundance, gyromagnetic ratio, γ, about 1.04 times that of 13 C) provide an extra NMR probe of the chemistry of the tanning process. The chemical shift of the 27 Al signal argues for octahedral coordination by six oxygen ligands (as opposed to the other common tetrahedral geometry resulting from Al (III) coordination by four ligands) [41]. The quadrupolar nature of the 27 Al nucleus with a nuclear spin I = 5/2 means that the 27 Al resonance lineshape is responsive to electric field gradients at the nucleus, which are a function of its bonded and non-bonded environment, particularly the nature and symmetry of the inner and outer coordination spheres.…”

Section: Tanning With Aluminium (Iii) and Glutaraldehydementioning

confidence: 98%

Tannin Fingerprinting in Vegetable Tanned Leather by Solid State NMR Spectroscopy and Comparison with Leathers Tanned by Other Processes

et al. 2011

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Solid state 13 C-NMR spectra of pure tannin powders from four different sources -mimosa, quebracho, chestnut and tara -are readily distinguishable from each other, both in pure commercial powder form, and in leather which they have been used to tan. Groups of signals indicative of the source, and type (condensed vs. hydrolyzable) of tannin used in the manufacture are well resolved in the spectra of the finished leathers. These fingerprints are compared with those arising from leathers tanned with other common tanning agents. Paramagnetic chromium (III) tanning causes widespread but selective disappearance of signals from the spectrum of leather collagen, including resonances from acidic aspartyl and glutamyl residues, likely bound to Cr (III) structures. Aluminium (III) and glutaraldehyde tanning both cause considerable leather collagen signal sharpening suggesting some increase in molecular structural ordering. The 27 Al-NMR signal from the former material is consistent with an octahedral coordination by oxygen ligands. Solid state NMR thus provides easily recognisable reagent specific spectral fingerprints of the products of vegetable and some other common tanning processes. Because spectra are related to molecular properties, NMR is potentially a powerful tool in leather process enhancement and quality or provenance assurance. OPEN ACCESSMolecules 2011, 16 1241

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“…All have been limited lo the state and spectra are referenced with respect to internal tetramethylsilane to solutions of the halide in acetonitrile, a strongly (20). For cross-comparison with existing compilations of boron coordinating solvent (7)(8)(9)(10)(11)(12)(13)(14). In acetonitrile both resonance spectra (21) 1nf;ared spectra of potassmm bromtde pellets of some prod&ucts were obtatned on Beckman Acculab 4 and Perkln-Elmer plexes' chosen for this study' This "lvent is "'-283 spectrometers Ramdn spectra of sollds and sulfur dtoxlde not truly inert since it forms a molecular complex solut~ons were obtalned by excttatlon wtth the 514 5 nm line of a with aluminum trichloride (15).…”

Section: Introductionmentioning

confidence: 99%

Complexing and exchange of boron, aluminum, and gallium chlorides with some Lewis bases

Glavinčevski¹,

Brownstein²

1981

Can. J. Chem.

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Boron trichloride and dimethyl sulfide form a 1:1 complex. It exchanges with excess boron trichloride by a displacement mechanism with an activation energy of 5.0 ± 0.5 kcal/mol and with excess dimethyl sulfide by a dissociation mechanism which has an activation energy of 20 ± 1 kcal/mol. The 1:1 complex of AlCl3 and dimethyl sulfide exchanges very rapidly with excess dimethyl sulfide. Equilibria and exchange reactions of AlCl3[(CH3)2O], AlCl3[(CH3)2O]2, and (CH3)2O are described. Rapid exchange is always found in the analogous gallium systems. BCl3 reacts with chloride ion to give BCl4− and B2Cl7−, which exchange rapidly with excess BCl3. AlCl3 reacts with Cl− and BCl4− to give AlCl4− which does not exchange with AlCl3.

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Aluminum complexes in solution as studied by aluminum-27. Nuclear magnetic resonance

Cited by 110 publications

References 5 publications

High Aluminum Resistance in Buckwheat1

High Aluminum Resistance in Buckwheat1

Tannin Fingerprinting in Vegetable Tanned Leather by Solid State NMR Spectroscopy and Comparison with Leathers Tanned by Other Processes

Complexing and exchange of boron, aluminum, and gallium chlorides with some Lewis bases

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