نتایج جستجو برای: ir spectra

تعداد نتایج: 171670  

Journal: :Journal of the American Chemical Society 2003
André Fielicke Roland Mitrić Gerard Meijer Vlasta Bonacić-Koutecký Gert von Helden

Infrared spectra of complexes of small vanadium oxide clusters with ethene are determined using infrared multiple photon dissociation (IR-MPD) spectroscopy in the range of 550-1850 cm-1. The structures of the complexes have been identified by comparison of the experimental spectra with the harmonic vibrational frequencies and corresponding IR intensities of possible isomers calculated with DFT ...

2015
Marcin Kubisiak Karolina Zelga Wojciech Bury Iwona Justyniak Krzysztof Budny-Godlewski Zbigniew Ochal Janusz Lewiński

Syntheses of organometallic initiators were conducted under a nitrogen atmosphere using standard Schlenk techniques. All reagents were of commercial grade and obtained from Sigma-Aldrich Co.. Solvents and the propionic acid used for the preparation of initiators were carefully dried and distilled under nitrogen atmosphere prior to use. TEMPO was sublimated and stored under nitrogen atmosphere. ...

Journal: :Journal of the American Chemical Society 2005
Ali Abo-Riziq Bridgit Crews Louis Grace Mattanjah S de Vries

We report spectroscopy of clusters of guanine base pairs with one and two water molecules. We recorded the vibronic spectra of the mass-selected GG(H2O) and GG(H2O)2 clusters using resonant two photon ionization (R2PI) and we used IR-UV double resonance spectroscopy to obtain ground state IR spectra of these clusters. We found that a single water molecule stabilizes one of two structures we had...

Journal: :Zeitschrift fur Naturforschung. Teil B. Anorganische Chemie, organische Chemie, Biochemie, Biophysik, Biologie 1972
E Fahr G Fürst P Maul H Wieser

UV irradiation of 1,3-dimethyluracil in ice-matrix yields four dimeric dimethyluracils (2 c) — (5 c) , which could be isolated by preparative thin-layer chromatography. Attemps for structure elucidation of these four dimers by UV, IR, NMR and mass-spectrometric methodes pointed out, that only NMR-spectra give structural evidences; by IR — not by mass-spectra — certain identification of dimers i...

2017
M. Hus M. HUS

Direct determination of the adsorbed amounts of surfactants on AgI by IR-spectroscopy is described. The adsorbed quantities are determined from the relationship between the intensities of the characteristic bands in IR-spectra of standard samples and the samples with adsorbed surfactants. The samples for IR-measurements are in the form of patterns consisting of AgI separated from the systems. T...

Journal: :Chang Gung medical journal 2006
Ying-Jen Chen Yih-Dih Cheng Hsin-Yi Liu Paul-Yann Lin Chia-Siu Wang

Fourier-transform infrared (FT-IR) microspectroscopic mapping can be used to distinguish between different tissue structures, and to increase the image contrast between normal and cancerous regions of a given tissue sample. This study demonstrates the biochemical changes associated with a consistent link between cancerous tissue and various molecular changes in the IR spectra of human pancreati...

2013
SHILPI GUPTA M. K. MAHESHWARI

Pentacoordinated copper(II) complexes were synthesized from tetradentate ligand N,N-bis (2-methyl-N-methylbenzimidazolyl)hexanediamide. Characterization has been done on the basis of elemental analysis, electronic spectra, IR studies, conductance data, magnetic properties, EPR and x-ray studies for the complexes. From analytical data, the stoichiometry of the complexes has been found to be 1:1 ...

Journal: :Physical chemistry chemical physics : PCCP 2005
Bridgit Crews Ali Abo-Riziq Louis Grace Michael Callahan Martin Kabelác Pavel Hobza Mattanjah S de Vries

We present the IR-UV double resonance spectrum of guanine monohydrate in the region 3100 cm(-1) to 3800 cm(-1) along with the energies and frequencies of these structures calculated at the non-empirical correlated ab initio RI-MP2/cc-pVDZ level. We assign the structures of guanine-water clusters by comparing the experimental spectra with the ab initio calculations and with the IR spectra of the...

2013
R. RENJITH

The IR and Raman spectra of the title compound have been recorded and analyzed. The harmonic vibrational wavenumbers were calculated theoretically using Gaussian09 software package. Calculations were performed by HF and DFT levels using the standard 6-31G* basis sets. The data obtained from vibrational wavenumber calculations are used to assign vibrational bands found in the IR and Raman spectr...

Journal: :Physical review. B, Condensed matter 1996
Pederson Jackson Porezag Hajnal Frauenheim

We report low-energy locally stable structures for the clusters Si 20 and Si21 . The structures were obtained by performing geometry optimizations within the local density approximation. Our calculated binding energies for these clusters are larger than any previously reported for this size regime. To aid in the experimental identification of the structures, we have computed the full vibrationa...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید