Applications in Inorganic Chemistry

Nakamoto, Kazuo

doi:10.1002/9780470405840.ch2

Cited by 31 publications

(11 citation statements)

References 1,729 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The “∆ criterion”, which is based on the difference between the values of the ν as (COO) and ν s (COO) vibration modes from the carboxylate group, was used to determine the coordination mode of this functional group [ 54 , 55 ]. If the difference between the asymmetric and symmetric vibrational modes of the carboxyl-type ligands in the synthesized compounds is greater than that of their ionic salts, there may be two types of interactions: if the value of ∆ is very large (>200 cm −1 ), this corresponds to a monodentate-type bond, whereas if the value is close to that of the ionic bond, it will be of the bridge type [ 56 ]. The ∆ν for the ZGluGO and ZAspGO compounds were 130, 231 cm −1 and 158, and 260 cm −1 , respectively.…”

Section: Resultsmentioning

confidence: 99%

Amino Acid Complexes of Zirconium in a Carbon Composite for the Efficient Removal of Fluoride Ions from Water

González-Aguiñaga

Pérez-Tavares

Patakfalvi

et al. 2022

IJERPH

View full text Add to dashboard Cite

Amino acid complexes of zirconia represent an entirely new class of materials that were synthesized and studied for the first time for the decontamination of fluoride ion containing aqueous solutions. Glutamic and aspartic acid complexes of zirconia assembled with thin carbon (stacked graphene oxide) platelets deriving from graphite oxide (GO) were synthesized by a two-step method to prepare adsorbents. The characterization of the complexes was carried out using infrared spectroscopy to determine the functional groups and the types of interaction between the composites and fluoride ions. To reveal the mechanisms and extent of adsorption, two types of batch adsorption measurements were performed: (i) varying equilibrium fluoride ion concentrations to construct adsorption isotherms at pH = 7 in the absence of added electrolytes and (ii) using fixed initial fluoride ion concentrations (10 mg/L) with a variation of either the pH or the concentration of a series of salts that potentially interfere with adsorption. The experimental adsorption isotherms were fitted by three different theoretical isotherm equations, and they are described most appropriately by the two-site Langmuir model for both adsorbents. The adsorption capacities of Zr-glutamic acid-graphite oxide and Zr-aspartic acid-graphite oxide are 105.3 and 101.0 mg/g, respectively. We found that two distinct binding modes are combined in the Zr-amino acid complexes: at low solution concentrations, F− ions are preferentially adsorbed by coordinating to the surface Zr species up to a capacity of ca. 10 mg/g. At higher concentrations, however, large amounts of fluoride ions may undergo anion exchange processes and physisorption may occur on the positively charged ammonium moieties of the interfacially bound amino acid molecules. The high adsorption capacity and affinity of the studied dicarboxylate-type amino acids demonstrate that amino acid complexes of zirconia are highly variable materials for the safe and efficient capture of strong Lewis base-type ions such as fluoride.

show abstract

Section: Resultsmentioning

confidence: 99%

Amino Acid Complexes of Zirconium in a Carbon Composite for the Efficient Removal of Fluoride Ions from Water

González-Aguiñaga

Pérez-Tavares

Patakfalvi

et al. 2022

IJERPH

View full text Add to dashboard Cite

show abstract

“…The strongest bonds in both structures are B-O bonds but whereas in Cu 3 (BO 3 ) 2 these bonds are within BO 3 planar triangles, in CuB 2 O 4 they form BO 4 tetrahedrons. The frequencies of eigenvibrations of a free BO 3 molecule are higher than those of a BO 4 tetrahedral molecule [37], and this can explain why higher frequencies are observed in Cu 3 (BO 3 ) 2 . It is worth noting, however, that in the compounds RFe 3 (BO 3 ) 4 (R is a rare earth ion), which also contain planar triangular BO 3 groups, the highest observed vibrational frequency was of about 1440 cm −1 .…”

Section: B Infrared Spectroscopymentioning

confidence: 97%

“…The primitive unit cell of triclinic Cu 3 (BO 3 ) 2 with Z = 10 contains 110 atoms which results in total 330 phonon modes. The group-theoretical analysis gives the following set of the lattice modes in the center of the Brillouin zone: ] groups can be found in [37]. Because of a low symmetry of the crystal as a whole and low site symmetries, all the phonons are nondegenerate.…”

Section: A Symmetry Analysismentioning

confidence: 99%

“…Low crystal symmetry of Cu 3 (BO 3 ) 2 allows one to observe Raman-active modes in all diagonal and off-diagonal polarization settings. The main types of lattice vibrations in the high-symmetry [BO 3 ], [CuO 4 ], [CuO 5 ], and [CuO 6 ] groups can be found in [37]. Because of a low symmetry of the crystal as a whole and low site symmetries, all the phonons are nondegenerate.…”

Section: Lattice Dynamics a Symmetry Analysismentioning

confidence: 99%

See 1 more Smart Citation

Lattice dynamics and electronic transitions in a structurally complex layered copper borate Cu3(BO3)2

Molchanova¹,

Prosnikov²,

Dubrovin³

et al. 2017

Phys. Rev. B

View full text Add to dashboard Cite

Copper borate Cu3(BO3)2 is a complex compound with a layered crystallographic structure in which the Jahn -Teller active and magnetic copper Cu 2+ ions occupy sixteen nonequivalent positions in the unit cell displaying controversial magnetic behavior. In this paper, we report on the infrared and Raman spectroscopic studies of the lattice dynamics and the electronic structure of 3d 9 copper states below the fundamental absorption band. The lattice dynamics is characterized by a large number of phonons due to a low P1 space group symmetry and a large unit cell with Z = 10. Unusually rich set of phonons was found in the low-energy part of the infrared and Raman spectra below 100 cm −1 , which we tentatively assign to interlayer vibrations activated by a crystal superstructure and/or to weak force constants for modes related to some structural groups. Several phonons show anomalous behavior in the vicinity of the magnetic phase transition at T N =10 K thus evidencing pronounced magnetoelastic interaction. No new phonons were found below T N , which excludes the spin -Peierls type of the magnetic transition. In the region of electronic transitions, a strong broad absorption band centered at ∼1.8 eV is observed, which we assign to overlapping of transitions between the 3d 9 states of Cu 2+ ions split by the crystal field in nonequivalent positions. The fundamental charge-transfer absorption band edge has a complex structure and is positioned around ∼2.8-3.0 eV.

show abstract

“…In Figure 3a, the ATR-FTIR spectra of all sulfate metal and mixed metal hydroxides (prior to any thermal treatment) are presented at the wavenumber regime where vibrational modes of bound sulfate units are expected. The 'ideal-case' of the free sulfate ion, belongs to a T d symmetry where a symmetric S-O stretching vibration (ν 1 ) at 983 cm −1 and an asymmetric, triply degenerate S-O stretching vibration (ν 3 ) at 1105 cm −1 are expected in the 800-1500 cm −1 range [32]. The former is IR inactive while the latter is IR active; both are Raman active.…”

Section: Insights Into the Molecular Structure Of Surface Sulfate Spe...mentioning

confidence: 99%

Characterization of Sulfated SnO2-ZrO2 Catalysts and Their Catalytic Performance on the Tert-Butylation of Phenol

et al. 2020

View full text Add to dashboard Cite

Understanding the catalytic behavior of sulfated metal oxides has been the topic of several research studies in the past few decades. Their apparent super-acidic behavior has been correlated with the molecular structure of the surface sulfate species. Herein, we couple FTIR and Raman spectroscopies to study the molecular structural evolution of surface sulfate species on mixed metal hydroxides as well as calcined oxides. We show that on the surface of hydroxides, monodentate and possibly bidentate species are dominant, while for SnO2-rich samples, clusters of polymeric sulfate species may also be present. After calcination, sulfate species bind strongly on the surface of mixed oxides, and different configurations can be seen with a range of S=O functionalities of varying strength. Through comparison of the catalytic performance of all sulfate oxides in the tert-butylation of phenol, it was found that SnO2-rich samples show high TBA conversion, with monoalkylated phenols as the primary product.

show abstract

Applications in Inorganic Chemistry

Cited by 31 publications

References 1,729 publications

Amino Acid Complexes of Zirconium in a Carbon Composite for the Efficient Removal of Fluoride Ions from Water

Amino Acid Complexes of Zirconium in a Carbon Composite for the Efficient Removal of Fluoride Ions from Water

Lattice dynamics and electronic transitions in a structurally complex layered copper borate Cu3(BO3)2

Characterization of Sulfated SnO2-ZrO2 Catalysts and Their Catalytic Performance on the Tert-Butylation of Phenol

Contact Info

Product

Resources

About