Search results for "Infrared"

New insights on the electronic, magnetic, electric and molecular structure of a bis-(4-cyanopyridine) iron(III) complex with the meso-tetrakis(4-meth…

2019

International audience; We have successfully synthesized and characterized a new low-spin iron(III) bis(4-cyanopyridine) complex with a meso-porphyrin substituted in the para positions of the phenyls by the methoxy group, namely the bis(4-cyanopyridine)[(meso-tetrakis(4-metoxyphenylporphyrinato)]iron(III) trifluoromethanesulfonate chlorobenzene monosolvate complex with the formula [FeIII(TMPP)(4-CNpy)2]SO3CF3.C6H5Cl (I). This species was characterized through ultraviolet–visible, Fourier-transform infrared and Mössbauer spectroscopy as well as by SQUID magnetometry, cyclic voltammetry, and X-ray crystallography. These characterizations indicated that our synthetic heme model is a low-spin (…

Cyclopentadienyl derivatives of octahedral carbonylcarbide hexaruthenium clusters: synthesis, NMR, IR and X-ray characterization

1996

Abstract The reaction of hexanuclear carbonylcarbide cluster Ru6C(CO)17 (1) with pentamethylcyclopentadiene by reflux in heptane leads to a new chelate cluster Ru6C(μ-η1-η5-CH2C5Me4)(CO)14 (2). The compound 2 contains a CH2 group α-bonded to one of the Ru atoms in the Ru6 cluster and a C5Me4-ligand η5-coordinated by the adjacent Ru atom of the Ru6 cluster. Reflux of 1 in hexane with two molecular equivalents of nickelocene, Ni(C5H5)2  NiCp2, used as a source of cyclopentadiene yields the Ru6C(CO)12Cp2 (3) cluster. The compounds 2 and 3 have been characterized by NMR and IR spectroscopy and their crystal structures determined by X-ray diffraction studies.

Embryonic stem cell differentiation studied by FT-IR spectroscopy

2007

We propose, here, an FT-IR method to monitor the spontaneous differentiation of murine embryonic stem (ES) cells in their early development. Principal component analysis and subsequent linear discriminant analysis enabled us to segregate stem cell spectra into separate clusters corresponding to different differentiation times - and to identify the most significant spectral changes during differentiation. Between days 4 to 7 of differentiation, these spectral changes in the protein amide I band (1700-1600 cm(-1)) and in the nucleic acid absorption region (1050-850 cm(-1)) indicated that mRNA translation was taking place and that specific proteins were produced, reflecting the appearance of a…

Volatile Organic Compounds (VOCs) for Noninvasive Plant Diagnostics

2013

Synthesis, chemical characterization, computational studies and biological activity of new DNA methyltransferases (DNMTs) specific inhibitor. Epigene…

2015

This work deals with the synthesis, the chemical characterization of dibutyltin(IV) complex of caffeic acid (Bu2Sn(IV)HCAF, caf1) and its cytotoxic action on tumor cells. The coordination environment at the tin center was investigated by FTIR, (119)Sn{(1)H} cross polarization magic angle spinning, electrospray ionization mass spectroscopy in the solid state and UV-vis, fluorescence and (1)H, (13)C and (119)Sn NMR spectroscopy in solution phases. Density functional theory study confirmed the proposed structures in solution phase and indicated the most probably stable conformation. The effects on viability of breast cancer MDA-MB231, colorectal cancer HCT116, hepatocellular carcinoma HepG2 an…

Partitioning study of polycyclic aromatic hydrocarbons between water and some selected water-insoluble phases

2007

An investigation on the partitioning of naphthalene and phenanthrene between water and some water-insoluble phases has been carried out by Uv-vis-NIR spectrophotometry. The analysis of the experimental results emphasized the role of intermolecular interactions and structural features of the hosting phases as driving forces of the partitioning of these polycyclic aromatic hydrocarbons. The critical comparison of the resulting distribution constants allowed to evaluate the potentials of some extracting phases to set up sensitive analytical methods and/or effective environment remediation technologies.

Collisional Broadening, Line Shifting, and Line Mixing in the Stimulated Raman 2-v2 Q-Branch of CH4

1991

0021-9606; Self-, argon-, and helium-broadening coefficients have been measured for 13 lines in the 2v2 Raman Q branch of CH4 using stimulated inverse Raman spectroscopy. The linewidths clearly show the symmetry-state dependence characteristic of pressure broadening, and inelastic processes in general, involving spherical-top molecules. Pressure-induced line shifts have also been measured for these features in pure methane. The pressure-shift coefficients do not display the symmetry-state dependence found for the linewidths. By applying the Rosenkranz perturbation treatment to a pair of collisionally mixed lines, we have been able to obtain an estimate of individual state-to-state contribut…

Determination of quality parameters of beers by the use of attenuated total reflectance-Fourier transform infrared spectroscopy

2005

Abstract The estimation of important quality parameters of beers, such as original and real extracts and alcohol content, has been evaluated by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) using a partial least square (PLS) calibration approach. Two sample populations, one consisting of 24 samples and other of 21 samples, obtained from the Spanish market and covering different types of beer were used. The first set was used for building and validating the model, whereas the second, measured 6 months after, was used for evaluating its robustness. The spectral range and the size of the calibration set and its suitability for building the PLS model have been …

Preliminary studies about thermal degradation of edible oils through attenuated total reflectance mid-infrared spectrometry

2009

Abstract Degradation of edible oils during their heating process has been evaluated through the determination of cis -unsaturation and trans -fatty acids together with free fatty acids as a function of time and temperature heating. Two types of cooking oils, sunflower and seed (mixture of different seeds non-detailed), were heated at three different temperatures (147, 171 and 189 °C) during a total time of 1920 min (32 h) shared out in four sessions of 8 h each one, and samples were studied from their spectra obtained by Fourier transform infrared spectrometry using attenuated total reflectance measurements. A critical comparison between different multivariate calibration models built based…

Comparison of conventional twist drill protocol and piezosurgery for implant insertion: an ex vivo study on different bone types.

2015

Objective The aim of this ex vivo study was to compare implant insertion procedures using piezosurgery and conventional drilling in different qualities of bone. Implant bed preparation time, generated heat, and primary implant stability were analyzed. Material and methods Fresh ex vivo porcine bone block samples (cancellous, mixed, and cortical bone) were obtained. The bone quality was quantified by ultrasound transmission velocity (UTV). Each bone sample received three implants of the same diameter using each of the techniques of piezosurgery and conventional twist drills. Time for preparation was taken and the temperature while performing the osteotomy was measured using infrared spectros…