Broadbands infrared spectroscopy

Figure 12.1 Schematic of the spectroelectrochemistry apparatus at the University of Dlinois. The thin-layer spectroelectrochemical cell (TLE cell) has a 25 p.m thick spacer between the electrode and window to control the electrolyte layer thickness and allow for reproducible refilbng of the gap. The broadband infrared (BBIR) and narrowband visible (NBVIS) pulses used for BB-SFG spectroscopy are generated by a femtosecond laser (see Fig. 12.3). Voltammetric and spectrometric data are acquired simultaneously.

As a final example, we discuss the use of broadband ultrafast infrared spectroscopy as a tool for monitoring electron transfer rates in dye-sensitized... 

Grubbs WT, Dougherty TP, Heilweil EJ. Vibrational energy redistribution in Cp Ir(CO)2 (Cp = j5-pentamethylcyclopentadienyl) studied by broadband transient infrared spectroscopy. Chem Phys Lett 1994 227 480-484. 

Heilweil EJ. Ultrashort-pulse multichannel infrared spectroscopy using broadband frequency conversion in LiI03. Optics Lett 1989 14 551-553. 

Arrivo SM, Kleiman VD, Dougherty TP, Heilweil EJ. Broadband femtosecond transient infrared spectroscopy using a 256 x 256 element indium antimonide focal-plane detector. Optics Lett 1997 22(19) 1488-1490. 

Dispersive Infrared Spectroscopy The dispersive IR spectrometer generally incorporates an IR broadband source, sample cell, a diffraction grating and one or more IR detectors. Dispersive IR instruments may provide simultaneous or sequential measurements. Respectively, the instrument may have a fixed grating and many detectors, or a movable grating and a single detector. In some cases, the grating may be replaced by one or more optical filters to resolve the desired wavelengths. A reference cell and associated optics to perform simultaneous differential analysis are also incorporated to improve sensitivity or reliability of measurement. 

McDowell and coworkers (15J studied the high resolution infrared spectrum of UF5 at ambient and low temperatures. This work was followed by a series of vibrational and electronic spectroscopic studies of matrix isolated UFg (16,17,18,19,20). In the first experiments, UFg deposited in Ar or CO matrices was vibrationally characterized by infrared spectroscopy and then exposed to broadband UV radiation at 10°K. In argon, photoreduction proceeded rapidly the 619 cirri UF5 infrared peak decreased in intensity while two new peaks grew in at 584 cirri anc 561 cirri. The new peaks were assigned to the expected UF5 photolysis product and a tentative C4V structure assignment was made. The wavelength dependence of the photoreduction was studied using a monochroma-tized UV source (1 kw Hg-Xe lamp, Schoeffel 6M-250 monochromator). The relative quantum efficiency of the UF5 dissociation per unit absorbance of UFg was found to be relatively constant in the allowed B-X absorption band (250-300 nm) (T7). Radiation in the... 

Friedrich Kremer is Professor of Molecular Physics, Materials Research Spectroscopy, Institute of Experimental Physics I, University of Leipzig, Germany. His research interests include broadband dielectric spectroscopy, time-resolved Fourier transform infrared (FTIR) spectroscopy, and experiments with optical tweezers. In 2005 he was awarded with the Karl Heinz Beckurts - Prize in 2011 he received the Wolfgang-Ostwald-Prize from the German Colloid Society. 

Heilweil, E. J. Applications of broadband transient infrared spectroscopy. In Ultrafast Infrared and Raman Spectroscopy Fayer, M. D., Ed. Marcel Dekker New York, 2001 pp 117-147. 

The in situ study in electrochemical cells of the catalyst surface is challenging due to low stuface sensitivity through the electrolyte. Several surface-sensitive techniques have been employed to probe the abundance and/or state of adsorbed surface species formed during formic acid electrooxidation broadband sum frequency generation [89, 90], surface-enhanced Raman spectroscopy [21], scanning tunneling microscopy [91], and Fourier transform infrared spectroscopy [19,26,27,31,32, 41,92-99],... 

A. Pifferi, A. Farina, A. Torricelli, G. Quarto, R. Cubeddu, and P. Taronia, Review Time-Domain Broadband Near Infrared Spectroscopy of the Female Breast A Focused Review from Basic Principles to Future Perspectives, /. Near Infrared Spectros., 20,223 (2012). 

Infrared spectroscopy continues to be a valuable tool for measuring species concentrations and temperatures in flames and combustion gases, especially in field-based studies. The advent of compact, fibre-coupled, tunable diode lasers operating at room temperatures is expanding the use of vibrational spectroscopy beyond the laboratory, and providing a useful complement to broadband methods currently in place. 

Spectroscopic studies, such as solution NMR and infrared spectroscopy, are often used in order to confirm the PEBA chemical composition [4,7] and to quantify the PA/PE ratio. Few authors have used spectroscopic studies to characterize the PEBA solid-state organization [7]. Figure 11 illustrates an NMR solid-state H-Wideline Separation (WISE) experiment with Sample H at room temperature, where the first dimension corresponds to the chemical shifts and provides information about the chemical structure. The second dimension corresponds to the broadband lines and gives information about local fields... 

Michaels, C.A., S.J. Stranick, L.J. Richter, and R.R. Cavanagh. 2000. Scanning near-field infrared microscopy and spectroscopy with a broadband laser source. J. Appl. Phys. 88 4832. 

Products were characterized by Fourier transform infrared spectrophotometry-attenuated total reflectance (FTIR-ATR), ultraviolet visible (UV-Vis) spectrophotometry, scanning electron microscopy (SEM), and broadband dielectric/impedance spectroscopy (BDS). New absorption bands were observed corresponding to the conjugated pol5mieric units by FTIR-ATR and UV-Vis spectrophotometric analysis. The influence of concentration of PEDOT-PSS and PEDOT on the composite electrospun nanofibers was studied by EIS. Morphologies of electrospun nanofibers were also investigated by SEM. 

---