Structure determination, by spectroscopy

GM Clore, MA Robien, AM Gronenborn. Exploring the limits of precision and accuracy of protein structures determined by nuclear magnetic resonance spectroscopy. J Mol Biol 231 82-102, 1993. 

I. Hargittai, The Structure of Volatile Sulfur Compounds, Reidel Publ., Dordrecht, 1985 (structures determined by electron diffraction and microwave spectroscopy). 

K. Wuthrich, Six years of protein structure determination by NMR spectroscopy What have we learned in Protein Conformation. Ciba Foundation Symposium 161, John Wiley Sons, Chichester, 1991, pp. 136-149. 

Boggs, J. E. 1983. The Integration of Structure Determination by Computation, Electron Diffraction and Microwave Spectroscopy. J. Mol. Struct. 97, 1-16. 

Dicyanofuroxan (3,4-dicyano-l,2,5-oxadiazole 2-oxide), the precursor to the NCCNO (see structure 11) species, has been studied in the solid and gas phases to obtain both structural and electronic information. The solid-state structure determined by X-ray diffraction gives an orthorhombic space group PnaZ, with a= 10.2578(14), b = 10.8818(12), and c= 10.2259(15) A. There are two independent molecules with similar geometries in the asymmetric unit. The gas-phase molecule was characterized by Hel photoelectron, Hel and HLtti(3i7 photoionization, and IR spectroscopy. The... 

Saaby S, Knudsen KR, Ladlow M, Ley SV (2005) The Use of a Continuous Flow-Reactor Employing a Mixed Flydrogen-Liquid Flow Stream for the Efficient Reduction of Imines to Amines. Chem Commun 23 2909-2911 Seebach D, Overhand M, Kilhnle FNM, Martinoni D, Oberer L, Hommel U, Widmer H (1996) Beta-Peptides Synthesis by Arndt-Eistert Homologation with Concomitant Peptide Coupling. Structure Determination by NMR and CD Spectroscopy and by X-ray Crystallography. Helical Secondary Structure of a Beta-Hexapeptide in Solution and its Stability Towards Pepsin. Helv Chim Acta 79 913-941... 

Electron energy-loss spectroscopy (EELS) is nowadays widely used to obtain the information with respect to chemical composition, oxidation state and electronic structure of solids. Since all catalytic processes concern the exchange of electrons between the reactants, EELS is extremely valuable in catalysts investigations [9, 49-57], EELS in an electron microscope exhibits the advantage of high spatial resolution in area of interests with simultaneous structure determination by electron diffraction and imaging. 

For both the hydrogen and chlorine compounds, until now only the C2 species are reported in the literature (33) whereas with fluorine substituents both isomers, difluorodisulfane as well as thiothionyl difluoride have been isolated and their structures determined by microwave spectroscopy (34). Surprisingly, the F2S=S molecule, which exhibits one of the shortest S=S bonds of onyl 189pm length, is thermodynamically more stable (34), and -even more - for both isomers, FSSF and F2S=S, almost identical ionization patterns are observed (35). In order to rationalize these experimental results, and especially to find out,whether there are chances for the spectroscopist to also detect the Cg isomers, 828=8 and Cl2S=S, hypersurface calculations were performed. 

Duus J0, Gotfredsen CH, Bock K (2000) Carbohydrate Structural Determination by NMR Spectroscopy Modem Methods and Limitations. Chem Rev 100 4589 Agrawal PK, Pathak AK (1996) Nuclear Magnetic Resonance Spectroscopic Approaches for the Determination of friterglycosidic Linkage and Sequence in Oligosaccharides. Phytochem Anal 7 113... 

Chemical shift correlated NMR experiments are the most valuable amongst the variety of high resolution NMR techniques designed to date. In the family of homonuclear techniques, four basic experiments are applied routinely to the structure elucidation of molecules of all sizes. The first two, COSY [1, 2] and TOCSY [3, 4], provide through bond connectivity information based on the coherent (J-couplings) transfer of polarization between spins. The other two, NOESY [5] and ROESY [6] reveal proximity of spins in space by making use of the incoherent polarization transfer (nuclear Overhauser effect, NOE). These two different polarization transfer mechanisms can be looked at as two complementary vehicles which allow us to move from one proton atom of a molecule to another proton atom this is the essence of a structure determination by the H NMR spectroscopy. 

Dimesityldioxirane, the first isolated crystalline derivative, offered the opportnnity to conduct a structure determination by means of X-ray analysis . Clearly, the structural data of the X-ray analysis (Figure 2) match well those obtained by microwave spectroscopy (Figure 1)". One striking feature of the dioxirane structure is the long oxygen-oxygen... 

Cario, L., Lefond, A., Palvadeau, A., Deudon, P., and Meerschault, C. (1999). Evidence of a mixed valence state for europium in the misfit layer compound [(EuS)i.5]i. i5NbS2 by means of a superspace structural determination, Mossbauer spectroscopy and magnetic measurements. /. Solid State Chem. 147, 58-67. 

Dell, A. Morris, H.R. (2001) Glycoprotein structure determination by mass spectroscopy. Science 291, 2351-2356. 

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