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Infrared difference spectra

Fig. 18. Infrared difference spectra before and after loading of H2602 (curve a) and H2802 (curve b) into TS-1 followed by 12 h evacuation (10-5 mbar) [Reprinted from Lin and Frei (133) with permission. Copyright (2002) American Chemical Society]. Fig. 18. Infrared difference spectra before and after loading of H2602 (curve a) and H2802 (curve b) into TS-1 followed by 12 h evacuation (10-5 mbar) [Reprinted from Lin and Frei (133) with permission. Copyright (2002) American Chemical Society].
Transient State Spectra. Figure 1 shows the near-infrared difference spectra for the formation of states at 30 ps (A) and P Q at 1.6... [Pg.207]

Carboxyl groups absorb at about 1710 cm1, and carboxylates at about 1570 cm-1. Infrared difference spectra in D20 solutions have been used to measure the pA s of abnormal carboxyl groups in a-lactoglobulin (7.5) and lysozyme (2.0, 6.5). [Pg.104]

Figure 6 Infrared difference spectra in the methylene scissoring region of DHPC 9HP (12 1 molar ratio) bilayeis containing (A) 0 mol % cholesterol (B) 8 mol %, (C) 29 mol %, and (D) 45 mol % cholesterol. The corresponding temperatures are the higher values of the 4.0 C intervals in which subtractions have been performed. Figure 6 Infrared difference spectra in the methylene scissoring region of DHPC 9HP (12 1 molar ratio) bilayeis containing (A) 0 mol % cholesterol (B) 8 mol %, (C) 29 mol %, and (D) 45 mol % cholesterol. The corresponding temperatures are the higher values of the 4.0 C intervals in which subtractions have been performed.
As demonstrated, different time-resolved FTIR techniques allow to study the complete photocycle of bacteriorhodopsin in the entire range from picoseconds to several milliseconds. Infrared difference spectra trace reactions which take place in different parts of the protein molecule. Isotopically labeled proteins or proteins with mutations at specific sites... [Pg.634]

Figure 12. Infrared difference spectra obtained on adsorption of methanol in HZSM-5 zeolites containing different aluminium concentrations at 423 K. Si Al ratios of (a) 12, (b) 27, (c) 16 and (d) 121. Data from reference 40. Figure 12. Infrared difference spectra obtained on adsorption of methanol in HZSM-5 zeolites containing different aluminium concentrations at 423 K. Si Al ratios of (a) 12, (b) 27, (c) 16 and (d) 121. Data from reference 40.
Figure 7. Infrared difference spectra. Top of azidomet-myoglobin vs. metmyoglobin (0.02M). Middle of azidomeU hemoglobin vs. bovine plasma albumin (O.OIM). Bottom of sodium azide in 0.05M citrate buffer (pH 3) vs. buffer. Figure 7. Infrared difference spectra. Top of azidomet-myoglobin vs. metmyoglobin (0.02M). Middle of azidomeU hemoglobin vs. bovine plasma albumin (O.OIM). Bottom of sodium azide in 0.05M citrate buffer (pH 3) vs. buffer.
Figure 8. Infrared difference spectra of carbonyl sperm whale myoglobins reconstituted from different hemes vs. metmyoglobin in phosphate buffer, pH 6 4, Top protoheme. Middle deu-teroheme. Bottom mesoheme. Figure 8. Infrared difference spectra of carbonyl sperm whale myoglobins reconstituted from different hemes vs. metmyoglobin in phosphate buffer, pH 6 4, Top protoheme. Middle deu-teroheme. Bottom mesoheme.
A completely different application of infrared spectroscopy is more related to functional aspects of proteins. To understand the molecular mechanisms of enzymes, information on the interaction of participating molecules is needed. The infrared difference spectra formed between... [Pg.502]

Fig. 2. Fourier transform infrared difference spectra of the photointermediates of bacte-riorhodopsin. The K and L difference spectra were obtained at 80 and 170 K, respectively. The M and M/N difference spectra were measured under steady-state illumination. (From Siebert. Copyright 1993 John Wiley Sons, Ltd. Reprinted by permission of John Wiley Sons, Ltd.)... Fig. 2. Fourier transform infrared difference spectra of the photointermediates of bacte-riorhodopsin. The K and L difference spectra were obtained at 80 and 170 K, respectively. The M and M/N difference spectra were measured under steady-state illumination. (From Siebert. Copyright 1993 John Wiley Sons, Ltd. Reprinted by permission of John Wiley Sons, Ltd.)...
Fig. 3. Fourier transform infrared difference spectra showing the influence of ATP on the Ca +-ATPase of sarcoplasmic reticulum. Thick trace, difference spectrum obtained by photolysis of caged ATP alone thin trace, difference spectrum obtained with the additional presence of ATPase. (Courtesy of A. Barth.)... Fig. 3. Fourier transform infrared difference spectra showing the influence of ATP on the Ca +-ATPase of sarcoplasmic reticulum. Thick trace, difference spectrum obtained by photolysis of caged ATP alone thin trace, difference spectrum obtained with the additional presence of ATPase. (Courtesy of A. Barth.)...
Finally, some strategies are described which are employed to interpret the infrared difference spectra at a molecular level. The first goal is the identification of bands caused by the protein and cofactors (chromophore, substrate, etc.). In the case of retinal proteins in which the retinal chromophore can be removed and replaced by an artificial one, the method of isotope labeling has provided detailed information. Not only does it help to identify the chromophore bands, but it also enables their assignment to specific normal modes from which structural information can be derived. Of course, a similar technique should be applicable to quinones... [Pg.524]

Fig. 3 In situ infrared difference spectra of CO adsorbed on (a) smooth Pt and Pd electrodes and (b) Pt and Pd that had been electrochemically deposited on glassy carbon. In each case the spectra were first measured with the electrode at the potential shown in the Fig. (0.2, 0.0 and —0.2 V) the potential was then raised to 0.7 V at which point all the adsorbed CO was oxidized to CO2 and is present in the electrolyte (0.5 M H2SO4). The positive going band at 2340 cm is due to solution-phase CO2 that resulted from the oxidation. Note that most of the CO is linearly bonded when adsorbed to Pt and bridge bonded when adsorbed on Pd. [Reprinted from Novel properties of dispersed Pt and Pd thin layers supported on GC for CO adsorption studied using in situ MS-FTIR reflection spectroscopy by G.-Q. Lu, S.-G. Sun, S.-P. Chen and L.-R. Cai, J. Electroanal. Chem., 1997, 421, 19-23 copyright 1997, with permission from Elsevier.]... Fig. 3 In situ infrared difference spectra of CO adsorbed on (a) smooth Pt and Pd electrodes and (b) Pt and Pd that had been electrochemically deposited on glassy carbon. In each case the spectra were first measured with the electrode at the potential shown in the Fig. (0.2, 0.0 and —0.2 V) the potential was then raised to 0.7 V at which point all the adsorbed CO was oxidized to CO2 and is present in the electrolyte (0.5 M H2SO4). The positive going band at 2340 cm is due to solution-phase CO2 that resulted from the oxidation. Note that most of the CO is linearly bonded when adsorbed to Pt and bridge bonded when adsorbed on Pd. [Reprinted from Novel properties of dispersed Pt and Pd thin layers supported on GC for CO adsorption studied using in situ MS-FTIR reflection spectroscopy by G.-Q. Lu, S.-G. Sun, S.-P. Chen and L.-R. Cai, J. Electroanal. Chem., 1997, 421, 19-23 copyright 1997, with permission from Elsevier.]...
Infrared difference spectra were also measured for the in vitro BChl. BChl was extracted from Ch, vinosum and purified by column chromatography. A tetrahydrofuran (THF) solution of BChl, for example, was placed in a CaF2 cell mounted with Pt electrodes, and IR absorption changes during electrolysis were recorded. [Pg.75]

Infrared difference spectra between the uncharged state DQ/ and the charge-separated state D Qa , denoted D Qfi /DQp for RC s containing ... [Pg.80]

Figure 7. Diffuse reflectance infrared difference spectra from 100 to 910 cm of only the plumbosiloxane contribution near 965 cm f. Spectra were obtained using the digital subtraction method and are not scale expanded. The adsorbate concentrations and measured peak to baseline intensity differences in Kubelka-Munk units are respectively, (A) 0.40 mg/m and 0.005, (B) 0.80 mg/m and 0.009, (C) 1.50 mg/m2 and 0.018, (D) 2.00 mg/m2 and 0.015, (E) 4.00 mg/m2 and 0.016, (F) 6.00 mg/m2 and 0.014. Figure 7. Diffuse reflectance infrared difference spectra from 100 to 910 cm of only the plumbosiloxane contribution near 965 cm f. Spectra were obtained using the digital subtraction method and are not scale expanded. The adsorbate concentrations and measured peak to baseline intensity differences in Kubelka-Munk units are respectively, (A) 0.40 mg/m and 0.005, (B) 0.80 mg/m and 0.009, (C) 1.50 mg/m2 and 0.018, (D) 2.00 mg/m2 and 0.015, (E) 4.00 mg/m2 and 0.016, (F) 6.00 mg/m2 and 0.014.
FIGURE 26 Infrared difference spectra after the illumination of intercalated all-trans retinal Shiff base in dimethyloctadecylammonium-montmorillonite. [Pg.239]

Figure 5.29 Infrared difference spectra of styrene-methacrylicacid (9 mol% MAA) copolymer blend with styrene-2-vinyl pyridine (17 mol% 2VPy)(room temperature) (reproduced (replotted) with permission from Motzner, H. R., Painter, P. C. and Coleman M.M., Macromolecules (2001) 34, p.8390,Copyright (2001) American Chemical Society)... Figure 5.29 Infrared difference spectra of styrene-methacrylicacid (9 mol% MAA) copolymer blend with styrene-2-vinyl pyridine (17 mol% 2VPy)(room temperature) (reproduced (replotted) with permission from Motzner, H. R., Painter, P. C. and Coleman M.M., Macromolecules (2001) 34, p.8390,Copyright (2001) American Chemical Society)...
Figure 203 Time-resolved Infrared difference spectra of photoexcited PYP (photoactive yellow protein) measured using a step-scan FT-IR spectrometer [141. Time is indicated on a common logarithmic scale after 50 ns from photoexcitation. AAbsorbance, absorbance difference a.u., absorbance unit. (Source Reprinted by permission from Macmillan Publishers Ltd Nature Structural and Molecular Biology [14]. Copyright 2001.)... Figure 203 Time-resolved Infrared difference spectra of photoexcited PYP (photoactive yellow protein) measured using a step-scan FT-IR spectrometer [141. Time is indicated on a common logarithmic scale after 50 ns from photoexcitation. AAbsorbance, absorbance difference a.u., absorbance unit. (Source Reprinted by permission from Macmillan Publishers Ltd Nature Structural and Molecular Biology [14]. Copyright 2001.)...
Figure 3.9 Infrared difference spectra after adsorption of lutidine on AIFj-H activated at 373 K. (a) equilibrium pressure at RT, (b) same as (a) but after evacuation at RT, (c) evacuated at 323 K, (d) evacuated at 373 K. (Reprinted with permission from [20] Copyright (2008) Wiley-VCH Verlag GmbH.)... Figure 3.9 Infrared difference spectra after adsorption of lutidine on AIFj-H activated at 373 K. (a) equilibrium pressure at RT, (b) same as (a) but after evacuation at RT, (c) evacuated at 323 K, (d) evacuated at 373 K. (Reprinted with permission from [20] Copyright (2008) Wiley-VCH Verlag GmbH.)...
See other pages where Infrared difference spectra is mentioned: [Pg.143]    [Pg.518]    [Pg.267]    [Pg.238]    [Pg.2057]    [Pg.230]    [Pg.164]    [Pg.117]   


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