FT-IR Spectroscopic Investigation of 4,4'-Bipyridine Adsorption on Metal Oxide Surfaces

1996 ◽  
Vol 50 (3) ◽  
pp. 310-315 ◽  
Author(s):  
Stephen A. Bagshaw ◽  
Ralph P. Cooney
Keyword(s):  
Three Dimensional ◽  
Acid Sites ◽  
Spectroscopic Technique ◽  
Metal Oxide Surfaces ◽  
Silica Alumina ◽  
Ft Ir ◽  
Ir Spectroscopic ◽  
First Time ◽  
Surface Chemistries

4,4‘-Bipyridine (4bipy) adsorption on the surfaces of silica, alumina, and titania and the infrared (IR) spectra obtained therefrom are reported for the first time. This paper constitutes the second part of a multi-faceted investigation into the development of a vibrational spectroscopic technique for the determination of distances between surface acid sites of three-dimensional solid acids. The aforementioned oxides were chosen because their surface chemistries are generally well understood and because they constitute the pillars within pillar interlayered clay (PILC) catalysts. However, there is little information in the literature regarding the surface interactions of this novel and potentially useful spectroscopic probe. The pore structures of PILC materials have been investigated through 4bipy adsorption, the results of which will be reported in a later paper. The spectra obtained for adsorption on the parent oxides are discussed with reference to earlier 4bipy and 2,2’-bipyridine (2bipy) adsorption studies and indicate that the mode of adsorption is a unidentate, “end-on” arrangement in agreement with that observed for adsorption on MgO. This mode of adsorption results in a reduction in molecular symmetry of the adsorbed 4bipy from D2 h to C2γ. A previously unreported observation involving the high-temperature cleavage of the inter-ring bond of 4bipy adsorbed on γ-alumina and titania Lewis acid sites is described.

FT-IR Analysis of Pillared Clay Pore Structure via Adsorbed Bipyridine Surface Probe Species

1996 ◽  
Vol 50 (10) ◽  
pp. 1319-1324 ◽  
Author(s):  
Stephen A. Bagshaw ◽  
Ralph P. Cooney
Keyword(s):  
Lewis Acid ◽  
Spectroscopic Method ◽  
Acid Sites ◽  
Pillared Clay ◽  
Lewis Acid Sites ◽  
Surface Probe ◽  
Ft Ir ◽  
First Time ◽  
Ft Ir Spectroscopy

Adsorption interactions of the bidentate molecules 2,2'-bipyridine and 4,4'-bipyridine with the surfaces of different alumina-pillar interlayered clays have been investigated by FT-IR spectroscopy. These interactions were examined in an attempt to establish a spectroscopic method for the determination of interpillar distances in the galleries of pillared clays. 2,2'-Bipyridine adsorbs in a bidentate C2 v, interaction to single Lewis acid sites on the surfaces of individual pillars and not to adjacent pillars, indicating that the distances between binding sites on adjacent pillars are too great to be successfully probed by this molecule. 4,4'-Bipyridine maintains the D2 h symmetry of the free molecule through interaction with Lewis acid sites on two adjacent pillars simultaneously via both ends of the molecule, thereby exhibiting possible utility as a probe of the interpillar distance. Surface-adsorbed monoprotonated 2,2'-bipyridinium cations are formed through interaction with Brönsted acid sites on the pillared clay surfaces. The IR spectrum of the surface-adsorbed protonated species suggests C2/i transoid symmetry and is presented for the first time.

Spectroscopic detection of Hg2+ in water samples using fluorescent carbon quantum dots as sensing probe

2021 ◽  
Vol 20 (1) ◽  
pp. 1-18
Author(s):  
Lavkesh Kumar Singh Tanwar ◽  
Srishti Sharma ◽  
Kallol K. Ghosh
Keyword(s):  
Quantum Dots ◽  
Water Samples ◽  
Carbon Quantum Dots ◽  
Spectroscopic Technique ◽  
Highly Sensitive ◽  
Ft Ir ◽  
Gibb’S Free Energy ◽  
Average Size ◽  
Ir Spectroscopic

Mercury (Hg2+) is remarked as toxic and hazardous element to global environment. Here, carbon quantum dots (CQDs) were synthesized by simple microwave assisted technique for Hg2+ detection in water samples via. fluorescence quenching and FT-IR spectroscopic approach. The morphology and chemical structure of synthesized CQDs was investigated by TEM, FT-IR, 13C-NMR, fluorescence and UV-vis spectroscopic technique. The resultant CQDs bears spherical morphology with an average size of 2–4 nm. The binding parameters, as Stern-Volmer quenching constant (Ksv) and binding constant for CQDs-Hg system was investigated by fluorescence method, whereas UV-vis techniques was employed for determination of thermodynamic parameters, as Gibb’s free energy (ΔG), enthalpy (ΔH) and entropy (ΔS) at three different temperature (295, 298 and 305 K). Moreover, selectivity assay for Hg2+ detection has been studied in presence of other metal ions by FT-IR as well as fluorescence spectroscopy. Analytical assay was also successfully applied for Hg2+ in spiked water samples collected from different areas of Chhattisgarh, with 98–99 recovery %. The detection of Hg2+ has been demonstrated in the range of 0 to 5.0μM with 3.25 nM detection limit. The present method is found to be simple, highly sensitive and selective for sensing of Hg2+ in aquatic environmental samples using CQDs as sensing probe.

scholarly journals MINERALOGICAL CHARACTERIZATION STUDIES ON UNBURNT CERAMIC PRODUCT MADE FROM ROCK RESIDUE ADDITIVES BY FT-IR SPECTROSCOPIC TECHNIQUE

2013 ◽  
Vol 22 ◽  
pp. 62-70 ◽  
Author(s):  
R. VIJAYARAGAVAN ◽  
S. MULLAINATHAN ◽  
M. BALACHANDRAMOHAN ◽  
N. KRISHNAMOORTHY ◽  
S. NITHIYANANTHAM ◽  
...  
Keyword(s):  
Qualitative Analysis ◽  
Functional Groups ◽  
Spectroscopic Technique ◽  
Ceramic Product ◽  
Minor Constituent ◽  
Mineralogical Characterization ◽  
Ceramic Samples ◽  
Ft Ir ◽  
Characterization Studies ◽  
Ir Spectroscopic

The usability of waste rock (rock residue) powder as an additive material in ceramic samples was investigated. Qualitative analysis was carried out to determine the major and minor constituent minerals present in ceramic bodies made from rock residue powder by using FT-IR spectroscopic technique. Further, the representative ceramic bodies are analyzed by FT-IR technique to yield more information about the functional groups and also to estimate the order or disorder of kaolinite structure.

Identification of Large Isotope Anomalies in Quartz by Infrared Spectroscopy

2019 ◽  
Vol 73 (7) ◽  
pp. 767-773
Author(s):  
Ryan C. Ogliore ◽  
Cosette Dwyer ◽  
Michael J. Krawczynski ◽  
Hélène Couvy ◽  
Max Eisele ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Fourier Transform Infrared Spectroscopy ◽  
Isotope Composition ◽  
Fourier Transform Infrared ◽  
Spectroscopic Technique ◽  
Far Field ◽  
Ft Ir ◽  
Ir Spectroscopic ◽  
Quartz Grains

We report an infrared (IR) spectroscopic technique to detect quartz grains with large isotope anomalies. We synthesized isotopically doped quartz and used Fourier transform infrared spectroscopy (FT-IR) in two different instruments: a traditional far-field instrument and a neaSpec nanoFT-IR, to quantify the shift in the peak of the Si–O stretch near 780 cm−1 as a function of isotope composition, and the uncertainty in this shift. From these measurements, we estimated the minimum detectable isotope anomaly using FT-IR. The described technique can be used to nondestructively detect very small (30 nm) presolar grains. In particular, supernova grains, which can have very large isotope anomalies, are detectable by this method.

The first uranyl complexes with valerate ions

2013 ◽  
Vol 69 (7) ◽  
pp. 721-726 ◽  
Author(s):  
Anton V. Savchenkov ◽  
Anna V. Vologzhanina ◽  
Larisa B. Serezhkina ◽  
Denis V. Pushkin ◽  
Viktor N. Serezhkin
Keyword(s):  
Three Dimensional ◽  
Uranyl Complexes ◽  
X Ray ◽  
Alkyl Groups ◽  
Neutral Compound ◽  
Homologous Compounds ◽  
Composition And Structure ◽  
Ft Ir ◽  
A Site ◽  
Ir Spectroscopic

FT–IR spectroscopy and single-crystal X-ray structure analysis were used to characterize the discrete neutral compound diaquadioxidobis(n-valerato-κ2O,O′)uranium(VI), [UO2(C4H9COO)2(H2O)2], (I), and the ionic compound potassium dioxidotris(n-valerato-κ2O,O′)uranium(VI), K[UO2(C4H9COO)3], (II). The UVIcation in neutral (I) is at a site of 2/msymmetry. Potassium salt (II) has two U centres and two K+cations residing on twofold axes, while a third independent formula unit is on a general position. The ligands in both compounds were found to suffer severe disorder. The FT–IR spectroscopic results agree with the X-ray data. The composition and structure of the ionic potassium uranyl valerate are similar to those of previously reported potassium uranyl complexes with acetate, propionate and butyrate ligands. Progressive lengthening of the alkyl groups in these otherwise similar compounds was found to have an impact on their structures, including on the number of independent U and K+sites, on the coordination modes of some of the K+centres and on the minimum distances between U atoms. The evolution of the KUO6frameworks in the four homologous compounds is analysed in detail, revealing a new example of three-dimensional topological isomerism in coordination compounds of UVI.

Quantitative determination of acid sites on silica–alumina

2010 ◽  
Vol 390 (1-2) ◽  
pp. 127-134 ◽  
Author(s):  
I.S. Pieta ◽  
M. Ishaq ◽  
R.P.K. Wells ◽  
J.A. Anderson
Keyword(s):  
Quantitative Determination ◽  
Acid Sites ◽  
Silica Alumina

scholarly journals EARTHQUAKES MAGNITUDE AS THE INDICATOR OF THE TECTONOSPHERE PHYSICOMECHANICAL PARAMETERS (to the 80 Anniversary of the Prominent Georgian Seismologist and Geophysicist Leah Ivanovna Tuliani)

2017 ◽  
Author(s):  
Л.Э. Левин
Keyword(s):  
Seismic Waves ◽  
Quantitative Characteristic ◽  
Three Dimensional ◽  
Tien Shan ◽  
Japanese Island ◽  
Empirical Determination ◽  
Original Procedure ◽  
Lithosphere Thickness ◽  
First Time

В статье приведены в сжатом виде результаты исследований, касающиеся строения литосферы Кавказского региона. Приведена оригинальная методика определения мощности литосферы по распределению энергии сейсмических волн с глубиной. Описана впервые выявленная особенность строения орогенов Большого и Малого Кавказа, где мощность литосферы оказалась меньше мощности коры. Приведено определение пространственного распространения т.н. астенолинз – зон частичного плавления в коре орогенов Большого и Малого Кавказа, являющихся очагами орогенного вулканизма. Подобные астенолинзы были также выявлены в коре орогенов Японской островной дуги и Тянь-Шаня и, таким образом, была установлена глобальная особенность строения многих постколлизионных орогенов. Приведены основные положения по эмпирическому определению квадратичной зависимости энергии сейсмических волн от магнитуды и количественной характеристики термодинамических параметров очага землетрясения и др. Results of studies, which are concerned the Caucasian region lithosphere structure are given in the compressed form. The original procedure of the lithosphere thickness determination from the energy distribution of seismic waves with the depth is given. The first time revealed special feature of the large and small Caucasus orogens structure is described, where the lithosphere thickness proved to be less than the thickness of crust. The three-dimensional propagation determination of the so-called astenolenses – zones of partial melting in the crust of the large and small Caucasus orogens, which are the centers of orogenic volcanism is given. Similar astenolenses were also revealed in the orogens crust of Japanese island arc and Tien Shan and was, thus, established the global special feature of the structure of many postkollision orogens. Basic provision of the quadratic dependence of seismic waves energy on the magnitude empirical determination and the quantitative characteristic of the thermodynamic parameters of the seismic center and others are given.

Three-dimensional hydrogen distribution and quantitative determination of titanium alloys via neutron tomography

The Analyst ◽  
2020 ◽  
Vol 145 (12) ◽  
pp. 4156-4163
Author(s):  
Lixia Yang ◽  
Linfeng He ◽  
Danqi Huang ◽  
Yaoqi Wang ◽  
Quanwei Song ◽  
...  
Keyword(s):  
Quantitative Determination ◽  
Titanium Alloys ◽  
Three Dimensional ◽  
Neutron Tomography ◽  
Distribution Analysis ◽  
Hydrogen Distribution ◽  
Thermohydrogen Processing ◽  
First Time

For the first time, neutron tomography was applied for 3D quantitative hydrogen distribution analysis in titanium alloys following thermohydrogen processing.

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