Spectroscopic analysis methods

Ebook "Russian contributions to analytical chemistry" offers a unique perspective and novel information on the significant contributions of Russian scientists to analytical chemistry and chemical analysis. Written by the Editor-in-Chief of the Journal of Analytical Chemistry, it discusses various examples of new methods and approaches originating in Russia, such as chromatography, electrothermal atomic absorption spectrometry, Kumakhov X-ray optics, the Spolský effect in fluorescent analysis and important innovations in mass spectrometry, which are already widely used.

165p tracanhphuonghoa1007 22-04-2024 6 3   Download

In the present study, two chemometric techniques, Artificial Neural Network (ANN) and Partial Least Square-Discrimination Analysis (PLSDA) have been assessed for their efficiencies for classification. Here, UV spectroscopic data are used as input.

6p viisac 23-09-2023 3 1   Download

In the present work, a modified b-nickel hydroxide (b-Ni(OH)2) electrode material with CuO has been prepared using a co-precipitation method. The structure and property of the modified b-Ni(OH)2 with CuO were characterized by X-ray diffraction (XRD), Fourier Transform infra-red (FT-IR), Raman and thermal gravimetric-differential thermal analysis (TG-DTA) techniques.

6p viberbers 09-08-2023 6 4   Download

In order to that, we fabricated MoS2 by utilizing a hydrothermal method for adsorption of tartrazine. As-prepared sample was characterized by spectroscopic analysis methods (XRD, BET, FTIR and SEM). The adsorption isotherm and thermodynamic of tartrazine on MoS2 were investigated.

6p vidoctorstrange 06-05-2023 3 2   Download

In this study, the synthesis of dimeric disulfide-Schiff bases was carried out using two methods. The structures of the obtained Schiff bases were elucidated by various spectroscopic methods as well as elemental analysis. The Schiff base derivative compounds (3a-6) were screened for in vitro antibacterial activity against multidrug-resistant microorganisms using microdilution method. All the tested compounds showed varying inhibition zones against the pathogens.

22p lyhuyenthu 31-01-2023 9 2   Download

Fourier-transform infrared spectroscopy (FTIR)is a well-established spectroscopic method in the analysis of small molecules and protein secondary structure. However, FTIR is not commonly applied for inline monitoring of protein chromatography.

8p viginny 23-12-2022 9 2   Download

The new complexes (1–3) were characterized by elemental analysis and spectroscopic methods and the molecular structure of 1a was determined by X-ray diffraction studies. These complexes were applied in the Suzuki–Miyaura cross-coupling reaction of phenylboronic acid with aryl halides in neat water. The activities of catalysts were monitored by gas chromatography–flame ionization detector and nuclear magnetic resonance.

10p langthannam 29-12-2021 12 0   Download

In this study, new cobalt phthalocyanine containing a 2-(2-benzothiazolylthio)ethoxy group at peripheral positions has been synthesized and characterized by spectroscopic methods (IR, UV-Vis elemental analysis, and mass spectroscopies). Catalytic activity of Co(II) phthalocyanine has been investigated in the presence of oxidants such as tert-buthylhydroperoxide, m-chloroperoxybenzoic acid, and H2 O2 . Co(II) phthalocyanine shows catalytically activity and product conversion under mild conditions.

8p langthannam 29-12-2021 11 0   Download

Two mono-benzimidazolium salts of resorcinarene have been prepared and used as ligands in Suzuki–Miyaura cross-coupling reactions. They have been fully characterized by 1H and 13C NMR, MALDI, and FT-IR spectroscopic methods, and their structures were confirmed by X-ray diffraction analysis. These two new resorcinarene-based monobenzimidazolium salts showed good catalytic activity for coupling reactions in DMF. The highest conversion was achieved for arylation of 4-bromotoluene using the resorcinarenyl mono-dimethylbenzimidazolium salt.

11p langthannam 29-12-2021 9 0   Download

Novel compounds based on the 1,2,4-triazole skeleton were synthesized. A class of 4-amino-5-alkyl-4H-1,2,4-triazole-3- thione created by reaction of thiocarbohydrazide with long-chain aliphatic carboxylic acids, and then the Schiff bases were obtained in the media of heat and microwave waves, in the presence and the absence of a catalyst. Their chemical structures were assayed by elemental analysis, also device spectroscopic methods.

69p langthannam 29-12-2021 4 0   Download

As a starting material, 7-tert-butyldibenzo [b,e] [1,4] dioxine-2,3-dicarbonitrile was prepared by the reaction of 4-tert-butylcatechol with 4,5-dichlorophthalonitrile. Metallophthalocyanine complexes (4–7) were obtained by cyclotetramerization of 7-tert-butyldibenzo [b,e] [1,4] dioxine-2,3-dicarbonitrile. All compounds were characterized by elemental analysis and other spectroscopic methods (IR, UV/Vis, and 1 H NMR). Phthalocyanine compounds remained nonaggregated in tetrahydrofuran at the studied concentration ranges.

12p tudichquannguyet 29-11-2021 19 1   Download

Many benzimidazole salts bearing a 3-phenylpropyl substituent (1a–1h) were synthesized and their structures were identified by 1H NMR, 13C NMR, and IR spectroscopic methods and elemental analysis. These N-heterocyclic carbene (NHC) precursors were used as a part of a catalytic system including Pd(OAc) 2 and the base in the Suzuki– Miyaura cross-coupling reaction under microwave irradiation. They were also used as catalysts in the cyclotrimerization of phenyl isocyanate to yield 1,3,5-triphenyl-1,3,5-triazinane-2,4,6-trione.

31p tudichquannguyet 29-11-2021 3 1   Download

In the current study, four new phenolic oxime ligands (HL1ox–HL4ox) containing diazo groups (-N=N-) were synthesized and used for liquid-liquid extraction of heavy metal ions [Cu(II), Ni(II), and Zn(II)]. The new compounds were characterized by analytical and spectroscopic methods. Solid-state structures of HL1ox–HL3ox were determined by single-crystal X-ray diffraction studies. Hirshfeld surface analysis of the compounds was performed to determine the contribution of different intermolecular contacts to the stability of the structures.

16p tudichquannguyet 29-11-2021 2 1   Download

Magnetic and optical bifunctional nanoparticles that combine easy separation, preconcentration, and efficient SERS capabilities have been fabricated with high sensitivity and reproducibility through a low-cost method. These gold nanoparticles attached on magnetic silica-coated cobalt nanospheres (Co@SiO2 /AuNPs) display the advantage of strong resonance absorption due to gaps at nanoscale between neighboring metal nanoparticles bringing large field enhancements, known as “hot spots”.

12p tudichquannguyet 29-11-2021 10 1   Download

The complexes of peripherally tetra-substituted metal-free (8), lead(II) (9), and zinc(II) (10) phthalocyanine derivatives were synthesized for the first time in this work. The structures of these new complex compounds have been elucidated using many spectral methods such as electronic absorption, FT-IR, 1H NMR, 13C NMR, elemental analysis, and mass spectra. The thermogravimetric behavior of compounds 8–10 was determined by thermogravimetric analysis method in addition to these spectral methods.

10p tudichquannguyet 29-11-2021 6 0   Download

In this study, conversion of seaweeds into hydrochars was investigated with the aim of obtaining a renewable energy feedstock. The seaweeds Fucus serratus and Alaria esculenta, and a mixture of seaweeds, mainly consisting of Cystoseria sp. and Laurencia sp., were subjected to hydrothermal carbonization (HTC) in subcritical water at three different temperatures: 200, 225, and 250 °C. Fuel characteristics and chemical properties of the derived hydrochars were determined using the standard fuel analysis and spectroscopic methods.

20p tudichquannguyet 29-11-2021 8 1   Download

Thes tructures of the crystalline compounds were characterized via their spectral analyses. General information about the structures of the newly obtained Hofmann-type clathrates was obtained from their vibration spectra by considering significant changes in the vibration peaks of the cyanide group, water ligand molecule, and guest molecules (water and 1,4-dioxane). The thermal behavior of the Hofmann-type clathrates was investigated in the range of 25–500°C.

14p tudichquannguyet 29-11-2021 6 0   Download

Schiff-base–bearing new bis(thiosemicarbazone) derivatives were prepared from terephthalaldehyde and various thiosemicarbazides. FT–IR, 1 H NMR, 13 C NMR, and UV–Vis spectroscopic methods and elemental analysis were used to elucidate the identification of the synthesized molecules. The in vitro antioxidant activity of the synthesized compounds was analysed with the 1,1-diphenyl-2-picryl hydrazyl free-radical–trapping process. The synthesized compounds exhibited lower antioxidant activity than the standard ascorbic acid. IC50 values of the synthesized molecules measured from 3.81 ± 0.

33p tudichquannguyet 29-11-2021 5 0   Download

This study reports the 3 new phthalonitrile derivatives, namely 4, 5 Bis-[4-(4-bromophenoxy) phenoxy] phthalonitrile (1), 4,5 Bis-[4-(4-chlorophenoxy) phenoxy]phthalonitrile (2), and 4, 5 Bis[4-(4-fluorophenoxy) phenoxy] phthalonitrile (3). Their octasubstituted zinc phthalocyanines (4, 5, 6) are reported for the first time in this study. The resulting compounds were characterized by utilizing some spectroscopic methods, such as UV-Vis, 1 HNMR, FT-IR spectroscopy, as well as mass spectraand elemental analysis.

22p tudichquannguyet 29-11-2021 6 1   Download

A pentaammineazidocobalt(III) complex, [Co(NH3)5N3](MnO4)2XH2O has been synthesized by an one-pot synthesis method. It was characterized by studies such as infrared (IR) and UV-visible spectroscopy. The single crystal X-ray structure analysis revealed that the title complex crystallizes in space group Cc. The cobalt center is six coordinated with slightly octahedral geometry. The supramolecular architecture is also formed by intermolecular N-H…O (anion and H2O) and Mn-O…O-H hydrogen bonds.

14p tudichquannguyet 29-11-2021 7 1   Download