Identification and structure determination

Modern Methods of Separation, Identification, and Structure Determination... 

In the last fifteen years most efforts aimed at identification and structure determination of dienes and of polyenes were related to studies of bio-originated compounds. The analysis of dienes and polyenes has not been reviewed, so far. The analysis of double bonds containing molecules utilizes the chemical reactivity of the bonds, and hence conjugated double bonds require different approaches than methods used for non-conjugated double bonds. One example is the use of the Diels-Alder reaction which yields derivatives of conjugated dienes whereas isolated double bonds are not affected. Some of the methods... 

The determination of the structure of synthetic dienes and polyenes is somewhat easier than the identification and structure determination of natural products. Obviously, this stems from the need to separate the latter compounds from very complex mixtures. 

Identification and structure determination are often closely allied to the problem of separation. Once a compound is separated, how do we determine whether it is identical to some previously known compound (identification) or, if that can t be done, how do we determine its chemical structure The spectroscopic properties of molecules have proven to be extremely informative for both identification and structure determination and this chapter is mainly concerned with the application of spectroscopy for such purposes. We will give you now an overview of the spectroscopic properties of the major classes of organic compounds. In subsequent chapters, spectroscopic properties will be discussed in the context of the class of compounds under consideration. 

Since the metal-sulfur distance in an inner-sphere sulfate complex appears in a region where a large number of other distances in the solution will also occur, a unique identification and structure determination of sulfate complexes is difficult to make unless difference methods can be used. Definite conclusions cannot generally be made on the basis of an analysis of a single diffraction curve only. Data for several solutions of different compositions are needed and a careful analysis... 

Identification and Structure Determination of Slightly Branched Amyloses... 

Mass spectrometry is one of the major techniques in the interdisciplinary field of proteomics. It provides a rapid, sensitive and reliable means of protein identification and structural determination, allowing for development in this newly baptised but yet classical field of biochemistry and biomedicine. The use of electrospray ionisation in conjunction with a tandem mass spectrometer (MS/MS) provides essential amino acid sequence information from the m/z values of the so-called b andy ions formed from cleavage of the amide bond of a protonated peptide. This reaction requires proton catalysis, and the mechanism is of interest in the present context, since it is closely related to the processes occurring in other protonated carboxylic acid derivatives. 

Proton magnetic resonance has been widely used for identification and structure determination of l,6,6aA4-trithiapentalenes and similar compounds such as l-oxa-6,6aA4-dithiapentalenes and 6aA 4- thia- 1,6-diazapentalenes. Chemical shifts and coupling constants have been collected (7lAHC(13)l61, p.229). Experiments have also been carried out using 13C NMR (74TL2783). 

Isobe, Y, M. Arita et al. 2012. Identification and structure determination of novel antiinflammatory mediator resolvin E3, 17,18-dihydroxyeicosapentaenoic acid,... 

R270 J. J. Ziarek, F. C. Peterson, B. L. Lytle and B. F. Volkman, Binding Site Identification and Structure Determination of Protein-Ligand Complexes by NMR A Semiautomated Approach , in Methods in Enzymology, ed. L. Kuo, Elsevier Inc., 2011, Vol. 493, Fragment-Based Drug Design Tools, Practical Approaches, and Examples, p. 241. 

For the application of spectroscopic methods for the identification and structure determination of polynuclear hydrocarbons see (29), and for the application of correlation analysis (chemical shifts of protons) for the identification of polyacetylnaphthalenes in mineral oil see (30). 

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