Darstellung und Charakterisierung der Tetrabutylammoniumsalze von [Tc2Cl8]2-, [Tc2Cl8]3- und [Tc2Br8]2- Preparation and Characterization of the Tetrabutylammonium Salts of [Tc2Cl8]2-, [Tc2Cl8]3- und [Tc2Br8]2-

1980 ◽  
Vol 35 (7) ◽  
pp. 797-801 ◽  
Author(s):  
W. Preetz ◽  
G. Peters
Keyword(s):  
Electronic Spectrum ◽  
Raman Spectra ◽  
Vibrational Spectra ◽  
High Extent ◽  
First Time

The reduction of [TcCl6]2- with Zn in conc. HCl after evaporation and extraction of ZnCl2 by diethylether yields a red-brown product from which after dissolving in dilute HCl by a solution of (TBA)Cl in CH2Cl2 (TBA)2[Tc2Cl8] and (TBA)3[Tc2Cl8] can be extracted. The separation is achieved by the much better solubility of the green (TBA)2[Tc2Cl8] in acetone compared with that of the grey-blue (TBA)3[Tc2Cl8]. On treatment of (TBA)2[Tc2Cl8] dissolved in acetone with bromine-free conc. HBr carmine red (TBA)2[Tc2Br8] is obtained for the first time. The vibrational spectra are similar and can be assigned according to the assumed D4h-symmetry. In the Raman spectra of both octachloroditechnetates the intensive Tc-Tc-vibration (A1g) is observed at 307 cm-1, for (TBA)2[Tc2Br8] it is found at 323 cm-1 . The electronic spectrum of (TBA)2[Tc2Cl8] agrees to a high extent with that of the corresponding Re compound

Raman characterization of Li(Al1-xCox)O2

2000 ◽  
Vol 15 (3) ◽  
pp. 583-585 ◽  
Author(s):  
G. Chen ◽  
W. Hao ◽  
Y. Shi ◽  
Y. Wu ◽  
S. Perkowitz
Keyword(s):  
Cathode Material ◽  
Raman Spectra ◽  
Lithium Batteries ◽  
Spinel Structure ◽  
Raman Band ◽  
Impurity Phase ◽  
First Time ◽  
Peak Widths ◽  
Raman Characterization

For the first time, we measured Raman spectra from Li(Al1-xCox)O2 (x = 0.5 to 0.9), a new cathode material for lithium batteries. Whereas LiCoO2 sintered at 400 °C develops a spinel structure, Li(Al1-xCox)O2 sintered at 380 °C is amorphous, as shown by its single broad Raman band. Li(Al1-xCox)O2 sintered at 700 or 900 °C shows Raman peaks independent of x that coincide with those from LiCoO2, indicating that Li(Al1-xCox)O2 has the α–NaFeO2 structure (space group R3m). Traces of the impurity phase Co3O4 appear in samples treated at 900 °C but not at 700 °C. The Raman peak widths exceed those in LiCoO2, suggesting that replacement of Co by Al increases disorder among the Li ions.

The Preparation and Low-Frequency Vibrational Spectra of Some Copper(I) and Silver(I) Alkane- and Arene-monothiolate Complexes

1979 ◽  
Vol 32 (7) ◽  
pp. 1443 ◽  
Author(s):  
GA Bowmaker ◽  
L Tan
Keyword(s):  
Raman Spectra ◽  
Infrared Spectra ◽  
Vibrational Spectra ◽  
Low Frequency ◽  
Far Infrared ◽  
New Methods ◽  
Thiolate Complexes ◽  
New Compounds ◽  
First Time ◽  
Far Infrared Spectra

A number of different methods for preparing anionic Group 1B metal thiolate complexes have been investigated. The compounds [Me4N] [CU2(SMe)3] and [Et4N] [Ag5(SBut)6] are reported for the first time, and new methods for preparing the previously known compounds [Et4N] [Cu5(SBut)6], [Me4N]2 [CU5(SPh)7] and [Et4N]2 [Cu5(SPh)7] are described. The far-infrared spectra of the above compounds, and of CuSMe, CuSBut, AgSBut, [Me4N]2 [CU4(SPh)6] and [Me4N]2 [Ag5(SPh)7] have been obtained, and metal-sulfur stretching bands are assigned in the 150-350 cm-1 region. The low-frequency Raman spectra have also been obtained for some of these compounds. Possible structures for the new compounds are considered in the light of the low-frequency vibrational spectra.

THE RAMAN SPECTRA OF SOME POLYSULPHURYL CHLORIDES AND FLUORIDES

1961 ◽  
Vol 39 (11) ◽  
pp. 2179-2188 ◽  
Author(s):  
R. J. Gillespie ◽  
E. A. Robinson
Keyword(s):  
Raman Spectrum ◽  
Raman Spectra ◽  
Vibrational Spectra ◽  
Characteristic Group ◽  
First Time

The Raman spectrum of disulphuryl chloride, S2O5Cl2, has been reinvestigated and the Raman spectra of S2O5F2, S2O5ClF, S3O8Cl2, S3O8F2, and the new compound S3O8ClF are reported for the first time. The vibrational spectra of these polysulphuryl halides are interpreted in terms of characteristic group frequencies by comparison with the vibrational spectra of simple sulphuryl compounds. The spectra are consistent with acyclic structures for the polysulphuryl halides.

Schwingungsspektren der käfigstrukturierten Verbindungen P4S3, P4Se3, As4S3 und As4Se3 / Vibrational Spectra of the Cage Compounds P4S3, P4Se3, As4S3 and As4Se3

1980 ◽  
Vol 35 (9) ◽  
pp. 1063-1069 ◽  
Author(s):  
W. Bues ◽  
M. Somer ◽  
W. Brockner
Keyword(s):  
Raman Spectra ◽  
Vibrational Spectra ◽  
Molten State ◽  
Arsenic Compounds ◽  
Cage Structure ◽  
Cage Compounds ◽  
First Time

The vibrational spectra of the cage compounds P4S3, P4Se3 and AS4S3 have been recorded in the solid and the molten state. The vibrational spectra of crystalline As4Se3, which decomposes during melting, have been investigated. The frequencies wore assigned using the concept of group frequencies.A new assignment of the Raman frequencies is proposed for P4S3 based on new po­larization data. The frequencies of the arsenic compounds are reported for the first time. The Raman spectra of the molten compounds suggest that the cage structure is retained in the molten state.

scholarly journals Raman Spectroscopy as a Novel Method for the Characterization of Polydioxanone Medical Stents Biodegradation

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5462
Author(s):  
Jan Loskot ◽  
Daniel Jezbera ◽  
Aleš Bezrouk ◽  
Rafael Doležal ◽  
Rudolf Andrýs ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectra ◽  
Hydrolytic Degradation ◽  
Biodegradable Stents ◽  
Ft Ir ◽  
Novel Method ◽  
First Time ◽  
Phosphate Buffered Saline ◽  
Ft Ir Spectroscopy

Polydioxanone (PPDX), as an FDA approved polymer in tissue engineering, is an important component of some promising medical devices, e.g., biodegradable stents. The hydrolytic degradation of polydioxanone stents plays a key role in the safety and efficacy of treatment. A new fast and convenient method to quantitatively evaluate the hydrolytic degradation of PPDX stent material was developed. PPDX esophageal stents were degraded in phosphate-buffered saline for 24 weeks. For the first time, the changes in Raman spectra during PPDX biodegradation have been investigated here. The level of PPDX hydrolytic degradation was determined from the Raman spectra by calculating the area under the 1732 cm−1 peak shoulder. Raman spectroscopy, unlike Fourier transform infrared (FT-IR) spectroscopy, is also sensitive enough to monitor the decrease in the dye content in the stents during the degradation. Observation by a scanning electron microscope showed gradually growing cracks, eventually leading to the stent disintegration. The material crystallinity was increasing during the first 16 weeks, suggesting preferential degradation of the amorphous phase. Our results show a new easy and reliable way to evaluate the progression of PPDX hydrolytic degradation. The proposed approach can be useful for further studies on the behavior of PPDX materials, and for clinical practice.

TBE in Sweden

2020 ◽  
Keyword(s):  
Genetic Characterization ◽  
Immunoglobulin M ◽  
Enzyme Linked Immunosorbent Assay ◽  
Second Phase ◽  
Serum Samples ◽  
Tick Borne Encephalitis ◽  
Specific Immunoglobulin ◽  
Tick Borne Encephalitis Virus ◽  
First Time

Tick-borne encephalitis virus (TBEV) was isolated for the first time in Sweden in 1958 (from ticks and from 1 tick-borne encephalitis [TBE] patient).1 In 2003, Haglund and colleagues reported the isolation and antigenic and genetic characterization of 14 TBEV strains from Swedish patients (samples collected 1991–1994).2 The first serum sample, from which TBEV was isolated, was obtained 2–10 days after onset of disease and found to be negative for anti-TBEV immunoglobulin M (IgM) by enzyme-linked immunosorbent assay (ELISA), whereas TBEV-specific IgM (and TBEV-specific immunoglobulin G/cerebrospinal fluid [IgG/CSF] activity) was demonstrated in later serum samples taken during the second phase of the disease.

Chemical Constituents and Antibacterial Activity of Cissus Aralioides.

2020 ◽  
Vol 17 ◽  
Author(s):  
Balogun Olaoye Solomon ◽  
Ajayi Olukayode Solomon ◽  
Owolabi Temitayo Abidemi ◽  
Oladimeji Abdulkarbir Oladele ◽  
Liu Zhiqiang
Keyword(s):  
Plant Extract ◽  
Chemical Constituents ◽  
Ethyl Acetate Fraction ◽  
Antibacterial Activities ◽  
Sub Saharan Africa ◽  
Chromatographic Purification ◽  
Whole Plant ◽  
Sub Saharan ◽  
First Time

: Cissus aralioides is a medicinal plant used in sub-Saharan Africa for treatment of infectious diseases; however the chemical constituents of the plant have not been investigated. Thus, in this study, attempt was made at identifying predominant phytochemical constituents of the plant through chromatographic purification and silylation of the plant extract, and subsequent characterization using spectroscopic and GC-MS techniques. The minimum inhibitory concentration (MICs) for the antibacterial activities of the plant extract, chromatographic fractions and isolated compounds were also examined. Chromatographic purification of the ethyl acetate fraction from the whole plant afforded three compounds: β-sitosterol (1), stigmasterol (2) and friedelin (3). The phytosterols (1 and 2) were obtained together as a mixture. The GC-MS analysis of silylated extract indicated alcohols, fatty acids and sugars as predominant classes, with composition of 24.62, 36.90 and 26.52% respectively. Results of MICs indicated that friedelin and other chromatographic fractions had values (0.0626-1.0 mg/mL) comparable with the standard antibiotics used. Characterization of natural products from C. aralioides is being reported for the first time in this study.

Green Synthesis and Spectroscopic Studies of Ag-rGO Nanocomposites for Highly Selective Mercury (II) Sensing

2018 ◽  
Vol 9 (1) ◽  
pp. 101-108 ◽  
Author(s):  
Shubhangi J. Mane-Gavade ◽  
Sandip R. Sabale ◽  
Xiao-Ying Yu ◽  
Gurunath H. Nikam ◽  
Bhaskar V. Tamhankar
Keyword(s):  
Green Synthesis ◽  
Color Change ◽  
Limit Of Detection ◽  
Aqueous Media ◽  
Suitable Condition ◽  
Cost Effective ◽  
Spectroscopic Studies ◽  
Calibration Plot ◽  
First Time

Introduction: Herein we report the green synthesis and characterization of silverreduced graphene oxide nanocomposites (Ag-rGO) using Acacia nilotica gum for the first time. Experimental: We demonstrate the Hg2+ ions sensing ability of the Ag-rGO nanocomposites form aqueous medium. The developed colorimetric sensor method is simple, fast and selective for the detection of Hg2+ ions in aqueous media in presence of other associated ions. A significant color change was noticed with naked eye upon Hg2+ addition. The color change was not observed for cations including Sr2+, Ni2+, Cd2+, Pb2+, Mg2+, Ca2+, Fe2+, Ba2+ and Mn2+indicating that only Hg2+ shows a strong interaction with Ag-rGO nanocomposites. Under the most suitable condition, the calibration plot (A0-A) against concentration of Hg2+ was linear in the range of 0.1-1.0 ppm with a correlation coefficient (R2) value 0.9998. Results & Conclusion The concentration of Hg2+ was quantitatively determined with the Limit of Detection (LOD) of 0.85 ppm. Also, this method shows excellent selectivity towards Hg2+ over nine other cations tested. Moreover, the method offers a new cost effective, rapid and simple approach for the detection of Hg2+ in water samples.

Vibrational spectra of aquadioxotetra; peroxodivanadates(V) M2[V2O2(O2)4(H2O)]·xH2O (M = N(CH3)4, Cs)

1990 ◽  
Vol 55 (6) ◽  
pp. 1485-1490 ◽  
Author(s):  
Peter Schwendt ◽  
Milan Sýkora
Keyword(s):  
Raman Spectra ◽  
Vibrational Spectra ◽  
Normal Coordinate Analysis ◽  
Force Constants ◽  
Infrared And Raman Spectra ◽  
Empirical Correlations ◽  
Normal Coordinate ◽  
Bond Lengths ◽  
Stretching Vibrations

The infrared and Raman spectra of M2[V2O2(O2)4(H2O)]·xH2O and M2[V2O2(O2)4(D2O)]·xD2O (M = N(CH3)4, Cs) were measured. In the region of the vanadium-oxygen stretching vibrations, the spectra were interpreted based on normal coordinate analysis, employing empirical correlations between the bond lengths and force constants.

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