Spectroscopy and Crystallography

The CMR chemical shifts of the symmetrically substituted pavine alkaloid argemonine are as indicated below. The A -methyl signal at 640.6 is shielded 

The absolute configuration of ( — )-argemonine methiodide has been confirmed by an X-ray analysis.  

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A competition between stoichiometric hydrogenation of acetone and acetophenone resulted in hydrogenation of the acetone [42]. Competitions of this type could be influenced by both the basicity of the ketone, as well as by the kinetics of hydride transfer to the protonated ketone. An intramolecular competition between an aliphatic and aromatic ketone resulted in preferential hydrogenation of the aliphatic ketone, with the product shown in Eq. (24) being isolated and fully characterized by spectroscopy and crystallography. Selective ionic hydrogenation of an aldehyde over a ketone was also found with HOTf and [Cp(CO)3WH],... 

Herbstein FH (1971) Crystalline 7t-molecular compounds (chemistry, spectroscopy and crystallography). In Dunitz ID, Ibers JA (eds) Perspectives in structural chemistry, vol 4. Wiley, New York... 

Following the same strategy, Landis prepared the l,l -ferrocenyldi-phosphines 53a-c featuring pendant benzoxaborolidine moieties (Scheme 33). 63 Reaction of 2-aminophenol with the ferrocene precursor 51 afforded 52 which was subsequently coupled with various boronic acids to give compounds 53a-c in good yields. Monomeric open structures were supported by 31P NMR spectroscopy and crystallography for 53a. 

As well as the above 2,3-dimercaptoalkanes a few other vicinal dithiols have also been sythesized. The interaction of methylmercury(II) with chelating agents such as BAL involves linear two-coordinate complexes and in only a few cases has chelation involved a bidentate ligand. In a search for evidence of thiol-containing bidentate chelation, Alcock et al.311 synthesized three sterically constrained dithiols - cyclohexane-1,2-dithiol, toluene-3,4-dithiol and bicyclo[2.2. l]heptane-2,3-dithiol - and demonstrated by spectroscopy and crystallography their formation of chelates with methylmercury(II) of the form (40). 

Herbstein, F. H. Crystalline 7r-molecular compounds chemistry, spectroscopy, and crystallography. In Perspectives m Structural Chemistry. (Eds., Dunitz, J.D., and Ibers, J.A.) pp. 166-395. Wiley New York, London, Sydney, Toronto... 

Brpycd-, 4-Fpcyd-, 4-Mepcyd-, 4-MeOpcyd-, 4-N02pcyd- and 4-Me2Npcyd-) were characterized by IR and 31P NMR spectroscopy and crystallography.38,59... 

Maths for Chemists Volume II Power Series, Complex Numbers and Linear Algebra builds on the foundations laid in Volume I, and goes on to develop more advanced material. The topics covered include power series, which are used to formulate alternative representations of functions and are important in model building in chemistry complex numbers and complex functions, which appear in quantum chemistry, spectroscopy and crystallography matrices and determinants used in the solution of sets of simultaneous linear equations and in the representation of geometrical transformations used to describe molecular symmetry characteristics and vectors which allow the description of directional properties of molecules. 

Table 8.2 Symmetry notation in the Schoenflies and Herman-Maugin systems commonly used in spectroscopy and crystallography, respectively.

The weak hydrogen bonds are studied by various methods. Experimentally, spectroscopy and crystallography are most often used. Formation constants or thermal properties of an interacting system also provide useful information. Conformational analyses of appropriate molecules may provide information, though indirect, for the weak... 

Paul fimile (dit Fran9ois) Lecoq de Boisbaudran (Cognac, 18 April 1838-Paris, 28 May 1912) also carried out much research on spectroscopy and crystallography, and on rare earths (see p. 909). 

Hiruma Y, Hass MA, Kikui Y, Liu WM, Olmez B, Skinner SP, Blok A, Kloosterman A, Koteishi H, Lohr F, Schwalbe H, Nojiti M, Ubbink M (2013) The structure of the cytochrome P450cam-putidare-doxin complex determined by paramagnetic NMR spectroscopy and crystallography. J Mol Biol, http // www.ncbi.nlm.nih.gov/pubmed/23856620... 

In the following sections an outline will be presented of the solution of some important structural problems in which the properties of the amino group are taken into account. It should be pointed out that the methods mentioned below, especially those based on spectroscopy and crystallography, are capable of yielding much more detailed information than that stemming from the interactions of the amino group with the rest of the molecule alone, but the discussion of such applications lies beyond the scope of the present chapter. 

The Brillouin Zone, an interface between Spectroscopy and Crystallography by S. F. A. Kettle and L. J. Norrby, J. Chem. 

Shen QJ, Jin WJ (2011) Strong halogen bonding of 1,2-diiodoperfluoroethane and 1,6-diiodoperfluorohexane with halide anions revealed by UV-vis, FT-IR, NMR spectroscopies and crystallography. Phys Chem Chem Phys 13 13721... 

Persson, I., D Angelo, P., De Panfilis, S., Sandstrom, M., and Eriksson, L. (2008) Hydration of lanthanoid(III) ions in aqueous solution and crystalline hydrates studied by EXAFS spectroscopy and crystallography the myth of the gadolinium break. Chem. Eur. J, 14, 3056-3066. 

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