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Gligor Jovanovski - One of the best experts on this subject based on the ideXlab platform.

  • minerals from macedonia xxix experimental and theoretical study of the vibrational spectra of extremely rare tl sulfate mineral from allchar dorallcharite
    Vibrational Spectroscopy, 2017
    Co-Authors: Petre Makreski, Stefan Stefov, Ljupco Pejov, Gligor Jovanovski
    Abstract:

    Abstract The work represents continuation of the vibrational spectra interpretation and Spectra-Structure Correlation carried out on the minerals originating from Macedonia, herein, with concern on the assignment of bands in the vibrational spectra of the only and very rare Tl-sulfate representative from Allchar mine – dorallcharite, (Tl,K)Fe3(SO4)2(OH)6. The mineral occurs in very small (0.1 mm) yellow balls and is structurally classified in the jarosite-alunite family. The SEM-EDS analysis revealed the following chemical formula, (Tl0.83K0.17)Fe3(SO4)2(OH)6 with the sample authenticity additionally confirmed by XRPD. The infrared spectrum shows great similarity with the previously interpreted jarosite IR spectrum. The spectral view in the region of the ν3(SO4), ν1(SO4) and ν4(SO4) modes makes it exceptionally difficult to discriminate between dorallcharite and jarosite. On the contrary, the bands arising from the Fe–O stretching modes around 505 and 468 cm−1, which are red shifted for 7–9 cm−1 due to the longer Fe–O(av) distances in dorallcharite (2.028 A) compared to shorter corresponding contacts in jarosite structure (2.012 A), facilitate their differentiation. The Raman spectrum was also interpreted confirming pure mineral phase due to the possibility for microscopically point-and-shoot spectral collection. Additionally, to support the assignment of the experimental bands, IR spectra of both minerals were theoretically simulated using a 3D periodic density functional theory approach applying various combinations of exchange–Correlation functionals.

Petre Makreski - One of the best experts on this subject based on the ideXlab platform.

  • minerals from macedonia xxix experimental and theoretical study of the vibrational spectra of extremely rare tl sulfate mineral from allchar dorallcharite
    Vibrational Spectroscopy, 2017
    Co-Authors: Petre Makreski, Stefan Stefov, Ljupco Pejov, Gligor Jovanovski
    Abstract:

    Abstract The work represents continuation of the vibrational spectra interpretation and Spectra-Structure Correlation carried out on the minerals originating from Macedonia, herein, with concern on the assignment of bands in the vibrational spectra of the only and very rare Tl-sulfate representative from Allchar mine – dorallcharite, (Tl,K)Fe3(SO4)2(OH)6. The mineral occurs in very small (0.1 mm) yellow balls and is structurally classified in the jarosite-alunite family. The SEM-EDS analysis revealed the following chemical formula, (Tl0.83K0.17)Fe3(SO4)2(OH)6 with the sample authenticity additionally confirmed by XRPD. The infrared spectrum shows great similarity with the previously interpreted jarosite IR spectrum. The spectral view in the region of the ν3(SO4), ν1(SO4) and ν4(SO4) modes makes it exceptionally difficult to discriminate between dorallcharite and jarosite. On the contrary, the bands arising from the Fe–O stretching modes around 505 and 468 cm−1, which are red shifted for 7–9 cm−1 due to the longer Fe–O(av) distances in dorallcharite (2.028 A) compared to shorter corresponding contacts in jarosite structure (2.012 A), facilitate their differentiation. The Raman spectrum was also interpreted confirming pure mineral phase due to the possibility for microscopically point-and-shoot spectral collection. Additionally, to support the assignment of the experimental bands, IR spectra of both minerals were theoretically simulated using a 3D periodic density functional theory approach applying various combinations of exchange–Correlation functionals.

Stefan Stefov - One of the best experts on this subject based on the ideXlab platform.

  • minerals from macedonia xxix experimental and theoretical study of the vibrational spectra of extremely rare tl sulfate mineral from allchar dorallcharite
    Vibrational Spectroscopy, 2017
    Co-Authors: Petre Makreski, Stefan Stefov, Ljupco Pejov, Gligor Jovanovski
    Abstract:

    Abstract The work represents continuation of the vibrational spectra interpretation and Spectra-Structure Correlation carried out on the minerals originating from Macedonia, herein, with concern on the assignment of bands in the vibrational spectra of the only and very rare Tl-sulfate representative from Allchar mine – dorallcharite, (Tl,K)Fe3(SO4)2(OH)6. The mineral occurs in very small (0.1 mm) yellow balls and is structurally classified in the jarosite-alunite family. The SEM-EDS analysis revealed the following chemical formula, (Tl0.83K0.17)Fe3(SO4)2(OH)6 with the sample authenticity additionally confirmed by XRPD. The infrared spectrum shows great similarity with the previously interpreted jarosite IR spectrum. The spectral view in the region of the ν3(SO4), ν1(SO4) and ν4(SO4) modes makes it exceptionally difficult to discriminate between dorallcharite and jarosite. On the contrary, the bands arising from the Fe–O stretching modes around 505 and 468 cm−1, which are red shifted for 7–9 cm−1 due to the longer Fe–O(av) distances in dorallcharite (2.028 A) compared to shorter corresponding contacts in jarosite structure (2.012 A), facilitate their differentiation. The Raman spectrum was also interpreted confirming pure mineral phase due to the possibility for microscopically point-and-shoot spectral collection. Additionally, to support the assignment of the experimental bands, IR spectra of both minerals were theoretically simulated using a 3D periodic density functional theory approach applying various combinations of exchange–Correlation functionals.

Ljupco Pejov - One of the best experts on this subject based on the ideXlab platform.

  • minerals from macedonia xxix experimental and theoretical study of the vibrational spectra of extremely rare tl sulfate mineral from allchar dorallcharite
    Vibrational Spectroscopy, 2017
    Co-Authors: Petre Makreski, Stefan Stefov, Ljupco Pejov, Gligor Jovanovski
    Abstract:

    Abstract The work represents continuation of the vibrational spectra interpretation and Spectra-Structure Correlation carried out on the minerals originating from Macedonia, herein, with concern on the assignment of bands in the vibrational spectra of the only and very rare Tl-sulfate representative from Allchar mine – dorallcharite, (Tl,K)Fe3(SO4)2(OH)6. The mineral occurs in very small (0.1 mm) yellow balls and is structurally classified in the jarosite-alunite family. The SEM-EDS analysis revealed the following chemical formula, (Tl0.83K0.17)Fe3(SO4)2(OH)6 with the sample authenticity additionally confirmed by XRPD. The infrared spectrum shows great similarity with the previously interpreted jarosite IR spectrum. The spectral view in the region of the ν3(SO4), ν1(SO4) and ν4(SO4) modes makes it exceptionally difficult to discriminate between dorallcharite and jarosite. On the contrary, the bands arising from the Fe–O stretching modes around 505 and 468 cm−1, which are red shifted for 7–9 cm−1 due to the longer Fe–O(av) distances in dorallcharite (2.028 A) compared to shorter corresponding contacts in jarosite structure (2.012 A), facilitate their differentiation. The Raman spectrum was also interpreted confirming pure mineral phase due to the possibility for microscopically point-and-shoot spectral collection. Additionally, to support the assignment of the experimental bands, IR spectra of both minerals were theoretically simulated using a 3D periodic density functional theory approach applying various combinations of exchange–Correlation functionals.

Enzo Santaniello - One of the best experts on this subject based on the ideXlab platform.

  • synthesis physicochemical and spectroscopic characterization of copper ii polysaccharide pullulan complexes by uv vis atr ftir and epr
    Carbohydrate Research, 2011
    Co-Authors: žarko Mitic, Milorad D Cakic, Goran M Nikolic, Ružica S Nikolic, Goran Nikolic, Radmila Pavlovic, Enzo Santaniello
    Abstract:

    Abstract Bioactive copper(II) complexes with polysaccharides, like pullulan and dextran, are important in both veterinary and human medicine for the treatment of hypochromic microcitary anemia and hypocupremia. In aqueous alkaline solutions, Cu(II) ion forms complexes with the exopolysaccharide pullulan and its reduced low-molecular derivative. The metal content and the solution composition depend on pH, temperature, and time of the reaction. The complexing process begins in a weak alkali solution (pH >7) and involves OH groups of pullulan monomer (glucopyranose) units. Complexes of Cu(II) ion with reduced low-molecular pullulan (RLMP, Mw 6000 g mol−1) were synthesized in water solutions, at the boiling temperature and at different pH values ranging from 7.5 to 12. The Cu(II) complex formation with RLMP was analyzed by UV–vis spectrophotometry and other physicochemical methods. Spectroscopic characterizations (ATR-FTIR, FT-IRIS, and EPR) and spectra–structure Correlation of Cu(II)–RLMP complexes were also carried out.