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Research Article
Synthesis and Characterization of a New Hybrid Polyoxometalate Compound: Bis(3-aminopropyl)ammonium Hexatungstotellurate(VI) Octahydrate
Issue:
Volume 12, Issue 6, December 2024
Pages:
117-123
Received:
4 October 2024
Accepted:
22 October 2024
Published:
12 November 2024
DOI:
10.11648/j.sjc.20241206.11
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Abstract: Synthesis strategy of hybrids Polyoxometalates have drawn a lot of attention owing to interesting. Herein, we describe, the one pot process used to synthesize a new hybrid polyoxotungstate, (C6H20N3)2[TeW6O24].8H2O, at a temperature of 200°C. This preparation was carried out by mixing equimolar amounts of H2WO4, C6H17N3, and H6TeO6. The compound was characterized by infrared and UV-visible spectroscopy techniques, as well as by X-ray diffraction. The compound crystallizes in the monoclinic system with the space group P21/c. The unit cell are: a = 8.74874(14) Å, b = 12.5894(2) Å, c = 18.5176(3) Å, α = 90°, β = 92.6078(14)°, γ = 90°. The compound consists of a non-protonated Anderson-type heteropolyanion [TeW6O24]6- stabilized by two organoammonium cations [C6H20N3]3+ and eight water molecules. The polyoxoanion [TeW6O24]6- adopts an Anderson-Evans type structure of class A. Thus, the polyanion is bult of six {WO6} units surrounding a {TeO6} octahedron. The six {WO6} are linked together by edges sharing and connected around the heteroatom, via oxygen atoms, forming a planar structure with approximate D3d symmetry. The cohesion of the three-dimensional structure is ensured by hydrogen bonds between the polyanions, the organoammonium groups, and the water molecules, thereby providing significant stability to the compound. UV–Visible absorption spectroscopy shows a strong absorption band at 296nm attributed to Ligand-Metal Charge Transfer (LMCT) transition of the O→W and the main IR absorption bands of the polyanion appear at: 942 cm⁻¹, 875 cm⁻¹, 766 cm⁻¹ and 599 cm-¹.
Abstract: Synthesis strategy of hybrids Polyoxometalates have drawn a lot of attention owing to interesting. Herein, we describe, the one pot process used to synthesize a new hybrid polyoxotungstate, (C6H20N3)2[TeW6O24].8H2O, at a temperature of 200°C. This preparation was carried out by mixing equimolar amounts of H2WO4, C6H17N3, and H6TeO6. The compound wa...
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Research Article
Physicochemical Characterization of Non-Wood Forest Product Oils: Towards a Strategic Positioning in Agroforestry
Issue:
Volume 12, Issue 6, December 2024
Pages:
124-134
Received:
12 October 2024
Accepted:
1 November 2024
Published:
22 November 2024
Abstract: NTFPs play a crucial role in local ecosystems and economies, especially in rural areas where they are an important source of income and food security. The main objective of the study is to characterize the physicochemical properties of oils from these NTFPs in order to better understand their economic, food and industrial potential. This includes the analysis of fatty acids, minor compounds, as well as functional properties such as acidity, saponification index and iodine. The kernels of the NTFPs studied are rich in proteins with contents of 18.9% for Blighia sapida, 21% for chrysophyllum albidum, 22.5% for carapa procera and 18.9% for Tieghemella heckelii. In addition, these almonds are rich in oil with a content of 47.7% Tieghemella heckelii, 52.2%, Blighia sapida, 52% Chrysophyllum albidum and 54% carapa procera. These plants are oilseeds. These lipids have low acidity levels varying between 1.2 ± 0.2 to 2.6 ± 0.3%. The iodine values of the oil are 73.1 ±0.4 for Chrysophyllum albidum, 70 ± 0.3 for Carapa procera, 93.2±0.5, for Blighia sapida and 91.7 ±0.2 Tieghemella heckelii. Regarding the saponification indices the values found are 193.7±0.8 for Blighia sapida, 189.4±0.7 mgKOH/g for Carapa procera, 154.6±0.2 for Chrysophyllum albidum and 147.3 ± 0.5 for Tieghemella heckelii. The saponification indices are between 147.3 ± 0.5 to 193.7 ± 0.8. The analysis of the composition of free fatty acids showed that Tieghemella heckelii oil is mainly composed of oleic acid at 53.6±0.1 and stearic acid at 38.5±0.3. Blighia sapida oil's major compounds are oleic acid (54.6±0.1%), palmitic acid (24.2±0.2%) and stearic acid (16.4±0.0 %). Carapa procera oil is mainly composed of oleic acid at 50.7±0.0%, palmitic acid at 23±0.1%, linoleic acid at 11±0.0% and stearic acid 10.4±0.1%. As for Chrysophyllum albidum oil, it is mainly composed of oleic acid at 47.6±0.3% and α-linolenic acid 17.8±0.1%. The results show that β-sitosterol and γ-tocopherol constitute the major compounds in all the oils studied. The results show that NTFP oils can be a sustainable alternative to conventional oils, making them attractive for growing sectors, particularly those linked to sustainable development. Thus, this study makes a significant contribution to the promotion of NTFPs with a view to economic and environmental sustainability, while highlighting their potential role in the development of modern agroforestry.
Abstract: NTFPs play a crucial role in local ecosystems and economies, especially in rural areas where they are an important source of income and food security. The main objective of the study is to characterize the physicochemical properties of oils from these NTFPs in order to better understand their economic, food and industrial potential. This includes t...
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Research Article
Synthesis, Spectroscopic Studies, Thermal Stability and Crystal Structure of New Bidentate Schiff Base and Its Cadmium Complex
Issue:
Volume 12, Issue 6, December 2024
Pages:
135-143
Received:
9 October 2024
Accepted:
4 November 2024
Published:
26 November 2024
Abstract: A new asymmetric bidentate Schiff base ligand was synthesized from a condensation reaction between 2,4-dichlorobenzaldehyde (C7H4Cl2O) and 1,3-pentanediamine (C5H14N2). A cadmium complex was prepared by adding Cd(II) iodide dissolved in methanol to a methanolic solution of the Schiff base ligand, in a ratio of 1:1. The ligand was characterized by elemental, spectroscopic (IR, 1H NMR), and thermogravimetric analyses. The ligand structure, thermally very stable, is revealed to be bidentate with two potential N-donor sites. The crystal structure of the Schiff base was elucidated by X-ray diffraction analysis. Compound crystallizes in a monoclinic system with a space group P21/n and a number of units per unit cell Z = 4. The unit cell parameters are: a =7.3885(2), b =16.9332 (4), c = 15.5624(4), and β = 90.4306(10). In the asymmetric unit of the ligand, the benzene rings C08/C10/C09/C11/C21/C17 and C20/C15/C13/C18/C22/C24 are in trans position with the aliphatic group with respect to the bonds (C07-N05) and (C19-N06), respectively. In addition, these two aromatic rings are located in two different planes, forming an angle of 3.60º between them, given that the dihedral angle between the ring C08/C10/C09/C11/C21/C17 and the aliphatic group N05-N06 is 67.49º. The spectroscopic data of the complex reveals a mononuclear complex where the Cd(II) ion is housed in a N2I2 coordination site with a slightly distorted tetrahedral geometry. The conductance data indicate that the complex is a neutral electrolyte.
Abstract: A new asymmetric bidentate Schiff base ligand was synthesized from a condensation reaction between 2,4-dichlorobenzaldehyde (C7H4Cl2O) and 1,3-pentanediamine (C5H14N2). A cadmium complex was prepared by adding Cd(II) iodide dissolved in methanol to a methanolic solution of the Schiff base ligand, in a ratio of 1:1. The ligand was characterized by e...
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Research Article
Thermal Conversion of Pregeijerene into Geijerene in Essential Oil of Chromolaena Odorata L. King & Robinson (Asteraceae)
Issue:
Volume 12, Issue 6, December 2024
Pages:
144-152
Received:
5 November 2024
Accepted:
9 December 2024
Published:
30 December 2024
DOI:
10.11648/j.sjc.20241206.14
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Abstract: It is well-known that geijerene is mostly associated with pregeijerene. These terpenes are believed to be thermoconvertible by a type of sigmatropic transposition order supra or antarafaciale. Our contribution to the study of the molecular pair consisted on a combination of statistical and analytical approach to the chemical composition of Chromolaena odorata essential oil. A compilation of chemical compositions of the samples obtained by steam distillation and analyzed by GC, presented a variation of this binomial proportions in different countries. For Ivory Coast, the results of analysis of 71 samples showed a dominance of geijerene proportion. We carried out a two-stage sampling by chemical variability factors (effects of site and period). We chose, at random, three different samples we submitted separately to chromatographic analysis (GC) and spectroscopic analysis (13C-NMR). It appears from this study that pregeijerene and geijerene were found in the essential oil with a relationship characterized by a polynomial degree 6 between these both molecules. Then during the chromatographic analysis, thermal conversion of pregeijerene into geijerene with the ratio 85.8% was observed. This result supported the idea of the coexistence of pregeijerene and geijerene in the essential oil of Chromolaena odorata. We intend to help clarify the kinetics and complete thermodynamics of this equilibrium.
Abstract: It is well-known that geijerene is mostly associated with pregeijerene. These terpenes are believed to be thermoconvertible by a type of sigmatropic transposition order supra or antarafaciale. Our contribution to the study of the molecular pair consisted on a combination of statistical and analytical approach to the chemical composition of Chromola...
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,
Lamine Yaffa*
