Infrared structural studies

J. R. Aronson, A. Danti, W. Lafferty, and R. C. Lord, Infrared Structural Studies Beyond Fifty Microns, Proc. IVth International Meeting on Molecular Spectroscopy, Bologna, Italy, Sept. 1959. 

Schneider J, Erdelen C, Ringsdorf H and Rabolt J F 1989 Structural studies of polymers with hydrophilic spacer groups. 2. Infrared-spectroscopy of Langmuir-Blodgett multilayers of polymers with fluorocarbon side-chains at ambient and elevated temperatures Macromolecules 22 3475-80... 

Ultraviolet absorptions ofvinylogous lactams were found by MOLCAO calculations and compared with experimental values (663). Infrared spectroscopic studies of vinylogous amides (664) and some fifty vinylogous urethanes (665) allowed configurational and structural assignments. The effect of enamine-imine equilibrium in a series of benzophenone derivatives was established (666) and the effect of structure on enamine basicity studied (667). 

Although cytosine was assigned structure 109 on the basis of early infrared spectral studies,and other infrared and ultraviolet spectral... 

Amino-pyrazines and -pyridazines have been shown to exist predominantly in the amino form by infrared spectroscopic studies (cf. Table VI). Ultraviolet spectral data have been interpreted to indicate that 4-aminocinnoline exists predominantly in the imino form 256, but this conclusion, which was based on comparison of its spectrum with those of cinnolin-4-one and 4-ethoxycinnoline, is probably incorrect. Ultraviolet spectroscopic data strongly support the predominance of amino structures for 2-aminopyrazine (257) and 2-aminoquin-oxaline how ever, the former compound was at first erroneously concluded to exist in the imino form from ultraviolet spectral evidence. Isolation of two isomers of 2-amino-8-dimethylamino-3-methylphenazine, assigned the amino and imino structures 258 and 259, respectively, has been claimed, but it is very unlikely that these assignments are correct. 

Since the vibrational spectra of sulfur allotropes are characteristic for their molecular and crystalline structure, vibrational spectroscopy has become a valuable tool in structural studies besides X-ray diffraction techniques. In particular, Raman spectroscopy on sulfur samples at high pressures is much easier to perform than IR spectroscopical studies due to technical demands (e.g., throughput of the IR beam, spectral range in the far-infrared). On the other hand, application of laser radiation for exciting the Raman spectrum may cause photo-induced structural changes. High-pressure phase transitions and structures of elemental sulfur at high pressures were already discussed in [1]. 

Kizhakevariam N, Weaver MJ. 1994. Structure and reactivity of bimetaUic electrochemical interfaces Infrared spectroscopy studies of carbon monoxide adsorption and formic acid electrooxidation on antimony-modified Pt(lOO) and Pt(lll). Surf Sci 310 183-197. 

Beden B, Juanto S, Leger JM, Lamy C. 1987b. Infrared spectroscopic study of the methanol adsorbates at a platinum electrode Part III Structural effects and behaviour of a polycrystalline surface. J Electroanal Chem 238 323-331. 

Sun SG, Cai WB, Wan LJ, Osawa M. 1999. Infrared absorption enhancement for CO adsorbed on Au films in perchloric acid solutions and effects of surface structure studied by cyclic voltammetry, scanning tunneling microscopy, and surface-enhanced IR spectroscopy. J Phys Chem B 103 2460-2466. 

S. J. Perstrelski, T. Arakawa, and J. F. Carpenter, Separation of freezing and drying-induced denaturation of lyophilized proteins using stress-specific stabilization. II. Structural studies using infrared spectroscopy, Arch. Biochem. Biophys., 303, 465... 

Cytisine is a tricyclic quinolizidine alkaloid that binds with high affinity and specificity to nicotinic acetylcholine receptors. In principle, this compound can exist in several conformations, but semi-empirical calculations at the AM 1 and PM3 levels have shown that stmctures 19 and 20 are more stable than other possible conformers by more than 50 kcalmol-1. Both structures differ by 3.7 kcalmol 1 at the AMI level and 2.0 kcalmol 1 at the PM3 level, although this difference is much smaller when ab initio calculations are employed <2001PJC1483>. This conclusion is in agreement with infrared (IR) studies and with H NMR data obtained in CDCI3 solution, which are compatible with an exo-endo equilibrium < 1987JP21159>, although in the solid state cytisine has an exo NH proton (stmcture 19) (see Section 12.01.3.4.2). 

The members of this group of shallow acceptors share a similar structure. They consist of a substitutional impurity binding one hydrogen or deuterium atom in its vicinity. Extensive far infrared spectroscopy studies... 

The question as to the best formulation of structures and species in some binary fluoride systems was the subject of extensive experimental investigations, involving infrared and Raman spectroscopy in the molten state and in solutions as well as NMR spectroscopy and conductometric and cryoscopic measurements. Some crystal structure studies have also been published. The systems of SeF4 with BF3, SbF5, AsF5, NbF5, and TaFs have been studied recently. 

Nuclear magnetic resonance has frequently been employed for general studies and for the structural studies of petroleum constituents (Bouquet and BaiUeul, 1982 Hasan et al., 1989). In fact, proton magnetic resonance (PMR) studies (along with infrared spectroscopic studies) were perhaps the first studies of the modem era that allowed stmctmal inferences to be made about the polynuclear aromatic systems that occm in the high-molecular-weight constituents of petroleum. 

Vandenbussche G, Clercx A, Clercx M, et al. Secondary structure and orientation of the surfactant protein SP-B in a lipid environment. A Fourier transform infrared spectroscopy study. Biochemistry 1992 31(38) 9169-9176. 

In the absence of suitable crystals for an X-ray structural study, combinations of FTIR, RR, XAS, EPR, ENDOR, XANES, and ESEEM spectroscopies were used to characterize the manganese site in the OEC. Vibrational spectroscopy, particularly low-frequency FT infrared and... 

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