IR attenuated total reflection

Vigano, C., Manciu, L., Buyse, F., Goormaghtigh, E., Ruysschaert, J.M. (2000). Attenuated total reflection IR spectroscopy as a tool to investigate the structure, orientation and tertiary structure changes in peptides and membrane proteins. Biopolymers, 55(5), 373-380. 

Attenuated total reflection IR spectroscopy can be used to investigate model as well as powder catalysts. 

Attenuated total reflection IR spectroscopy is an established tool in a variety of research fields. The theory is well documented, but the application of this method for investigations of catalysts under working conditions has been explored only... 

More significantly, when calorimetry is combined with an integral kinetic analysis method, e.g. a spectroscopic technique, we have an expanded and extremely sophisticated method for the characterisation of chemical reactions. And when the calorimetric method is linked to FTIR spectroscopy (in particular, attenuated total reflectance IR spectroscopy, IR-ATR), structural as well as kinetic and thermodynamic information becomes available for the investigation of organic reactions. We devote much of Chapter 8 to this new development, and the discussion will focus on reaction calorimeters of a size able to mimic production-scale reactors of the corresponding industrial processes. 

More recently, Markovich et al. (91) utilized a combination of solid-state infra-red (IR) and NMR methods to study the amorphous to crystalline API transition of SCH 48461 in solid dispersion capsule formulations. In this illustrative study, dissolution testing initially revealed inter-and intralot variations of capsules stored under accelerated stability conditions (25°C/60% RH, 30°C/60% RH, and 40°C/80% RH). PXRD analysis could not explain the dissolution data being collected on lots stored at accelerated conditions and revealed no differences from original diffraction patterns. Two additional analytical techniques, attenuated total reflectance IR (ATR-IR) spectroscopy and solid-state 13C NMR spectroscopy, were employed to study the physical form in the actual solid dispersion formulations. 

ID IQ 2D 2D-NMR 2h2o 2Q 3Q 9BEN A1 ABS AC ACM ACN AFM Al-CSM ALMA-i5 Al-m-EPDM AN AO APT ASTM ATR ATR-IR B/S BABA Two-dimensional Single-quantum One-dimensional Deuteron solid-state NMR Deuterated water Double-quantum Triple-quantum 9 borobicyclo [3, 3, 1] nonane Amide 1 Acrylonitrile-butadiene-styrene terpolymer Accelerator Acrylate rubber Acrylonitrile Atomic Force Microscopy Aluminium salt of chlorosulfonate polyethylene Allyl-rf5 methacrylate Aluminium salt of maleated EPDM Acrylonitrile 1-Allyl oxyoctane Attached Proton Test American Standards for Testing and Materials Attenuated total reflectance spectroscopy Attenuated total reflectance-IR spectroscopy Butadiene/styrene Back-to-back... 

Biirgi (2005) described equipment combining attenuated total reflection IR with reflectance UV-vis spectroscopy. A fiber optical probe was positioned parallel to the surface normal of the internal reflection element in front of a fused silica window in the reactor. The distance from the probe to the catalyst layer was about 4 mm. A second fiber optical arrangement allowed simultaneous acquisition of transmission UV-vis spectra of the effluent liquid from the reactor cell. All measurements were performed with the catalyst at 303 K. 

R571 C. Vigano, L. Manciu, F. Buyse, E, Goormaghtigh and J.-M. Ruysschaert, Attenuated Total Reflection IR Spectroscopy as a Tool to Investigate the Structure, Orientation and Tertiary Structure Changes in Peptides and Membrane Proteins , Biopolymers, 2001, 55, 373... 

Figure 1. Attenuated total reflectance IR spectra of poly-(phenylene oxide) film before and after Pyrex-filtered Hg lamp irradiation.

Solution-phase reactions can be followed conveniently by simple means such as TLC, conventional NMR or UV, whereas solid-phase synthesis requires either prior cleavage from the support or special equipment, e.g. ATR (attenuated total reflection)-IR or MAS (magic angle spinning)-NMR. This difference affects primarily the development of new reactions but may also be relevant for the actual library synthesis, e.g., checking completion of a reaction or the quality of intermediates. 

Bonalumi, N., Burgi, T., Baiker, A. (2003) Interaction between ketopanto-lactone and chirally modified Pt investigated by attenuated total reflection IR concentration modulation spectroscopy, J. Amer. Chem. Soc. 125, 13342-13343. 

The application of IR spectroscopy to organic sorbates has been primarily limited to gas-phase a orption kinetics and gas-phase catalysis (21). The usefrilness of IR for investigating sorption/desorption processes in situ, has been demonstrated for the selectivity of conformer adsorption at mineral surfaces (22). Strong absorption of H O vibrational modes by IR radiation has been a major hindrance in the application of IR spectroscopy to study organic sorption at aqueous-mineral interfaces. Attenuated total reflectance-IR (ATR-IR) spectroscopy and the use of DjO in the aqueous phase minimizes the water absorption problem. Figure 3 details the ATR setup used in this study. Clay pastes were loaded into Teflon plaques and clamped to both sides of a vertical ATR prism. Silicon sealant around the edges of the plaques prevented water evaporation during extended data collection times (up to 2 days). The area of the D O... 

Song S.-W., Zhuang G. V., Ross P. N. Surface Film Formation on FiNiosCooi5Aloo502 Cathodes Using Attenuated Total Reflection IR Spectroscopy, J. Electrochem. Soc. 2004, 151,A1162-A1167. 

PA-6/EVAc/EVAc-g-MA Attenuated total reflectance IR/mechanical properties/morphology/properties vs. MA content (1-6 %) Bhattacharyya et al. 2001, 2005... 

Chromate adsorption onto ferrihydrite was studied by attenuated total reflection IR spectroscopy (ATR-IR) and theoretical frequency calculations (Johnston and Chrysochoou 2012). The calculations were done for several model arranganents, shown in Figure 9.21. It was found that the results are consistent with the formation of monodentate and bidentate surface complexes. Monodentate complexes (Figure 9.21e) are dominaut at low surface coverage aud pH > 6.5, and bidentate complexes (Figure 9.21f) form at high surface coverage aud pH < 6. 

In order to determine the composition and structure of a biomaterial surface different methods which provide varying degrees of information are commonly used (Fig. 6). Surface-sensitive infrared spectroscopy suppHes the characteristic absorption bands of functional groups with an informational depth of 0.1-10 pm by measurement in attenuated total reflectance (IR-ATR). In the case of samples with rough surfaces photoacoustic spectroscopy (PAS), which allows an informational depth of approximately 20 pm, can be used [72]. The achieved informational depths are usually larger than the thickness of the modified interface, so that the spectra include information on the bulk composition as well. As a consequence, surface-sensitive infrared spectroscopy is often not sensitive enough for the characterization of the modified surfaces. 

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