X-ray studies, for

Up to the beginning of the 1990 s most of the work on thiooligosaccharides was devoted to their synthesis. During the last few years, tailor-made complex or sophisticated thiooligosaccharides were obtained and used both in biochemical and X-ray studies for getting a better understanding of the mechanism of action of glycanases. 

Azoles with bulky substituents near the donor site, such as 1,2-dimethylimidazole and 3,5-dimethylpyrazole, result in lower coordination numbers.36,37 When a ligand such as 3(5)-methylpyrazole is used, in which the methyl group is adjacent to the donor site in one tautomer and distant in the other tautomer, coordination takes place exclusively through the non-sterically-hindered form of the ligand, i.e. the 5-methylpyrazole. This has been proved by X-ray studies for this ligand38 and for indazole (4).39... 

Phenrat, T., Marhaba, T.F. and Rachakornkij, M. (2005) A SEM and X-ray study for investigation of solidified/stabilized arsenic-iron hydroxide sludge. Journal of Hazardous Materials, 118(1-3), 185-95. 

The gross structural features of this type of complex were first postulated by Chatt et al. 34) and later confirmed by X-ray studies for the platinum(II) analogs 211, 291). In this type of complex, the OR group is trans to the Pd(II), with the alkoxy group exo and the Pd(II) endo. Adducts have also been prepared in which the nucleophile is an acetate or a carbanoid species such as malonate or acetoacetate 180). 

Diels-Alder reaction to polycyclic hydrocarbons. The structure of the intermediate metallo-adduct has been determined by X-ray studies for a rhodium complex. ... 

The complexes exhibit thermochromism as the 3dz2-4pz transition for the nickel(II) and the 4dz2-5pz transition for the palladium(II) ions are sensitive to the intermolecular separation. Therefore, there is a blue shift of these bands as the temperature is increased corresponding to an increase in the internal separation. X-ray studies for a palladium(II) complex, where n = 12, supports this premise as the intermolecular separation is 3.3 A at room temperature compared to 3.5 A at 150°C. 

The electron-deficient Fischer carbene carbon is affected by the presence of the lone pair(s) of its rr-donor substituents, denoted ORflp). Structure 11.1 shows how the ) and OR(lp) orbitals compete fw n bondii to the carbene carbon. This can be described in VB (valence bond) language by resonance between 11.2 and 11.3. The real structure often re.sembles lU rather than 11.2 as shown by tiie long M-C and short C-O bonds found by X-ray studies. For electron counting purposes we regard the Fischer carbene as an L-type ligand such as CO. Note that the true M=C bond order is less than 2, thanks to die contribution of 11.3. 

The ordering phenomena were also found for ionic ttopolymers in solutions. The first X-ray study for biopolymers was done by Bernal and Funkuchen in 1941, as mentioned above [2]. However, the polymer concentration was very high in their experiments. Thanks to recent technical developments in the diffraction methods, it became feasible to perform X-ray scattering experiments at relatively low concentrations and at low scattering angles. 

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