The reactivity of a N-heterocyclic carbene (NHC) with a pseudo-acid (ester in this case) is described. The product results from an unusual C-H bond activation. The structure of the product has been established by a single crystal diffraction study.

1-Acetyl-3-(4-chlorophenyl)-5-(4-methylphenyl)-2-pyrazoline has been synthesized and characterized by elemental analysis, IR and X-ray single crystal diffraction. Density functional (DFT) calculations have been carried out for the title compound by using the B3LYP method at the 6-311G** basis set level. The calculated results show that the predicted geometry can reproduce well the structural pa...

X-ray crystallography provides the most accurate models of protein-ligand structures. These models serve as the foundation of many computational methods including structure prediction, molecular modelling, and structure-based drug design. The success of these computational methods ultimately depends on the quality of the underlying protein-ligand models. X-ray crystallography offers the unparal...

Knowledge of protein structure provides essential insight into function, enhancing our understanding of diseases and enabling new treatment development. X-ray crystallography has been used to solve the structures of more than 100 000 proteins; however, the vast majority represent long-lived states that do not capture the functional motions of these molecular machines. Reactions triggered by the...

Standard X-ray crystallography methods use free-atom models to calculate mean unit-cell charge densities. Real molecules, however, have shared charge that is not captured accurately using free-atom models. To address this limitation, a charge density model of crystalline urea was calculated using high-level quantum theory and was refined against publicly available ultra-high-resolution experime...

Until recently, there were no examples of RNAs whose structures had been determined by both NMR and x-ray crystallography, and thus there was no experimental basis for assessing the accuracy of RNA solution structures. A comparison of the solution and the crystal structures of two RNAs is presented, which demonstrates that NMR can produce solution structures that resemble crystal structures and...

Transthyretin (TTR) is a homotetrameric plasma protein that, as a result of a set of not yet fully characterized conformational changes, forms fibrillar aggregates that are the major protein component of amyloid deposits. More than 80 mutations associated with TTR amyloid deposition have been described in the literature. X-ray crystallography was used to elucidate the three-dimensional structur...

Knowledge gained through x-ray crystallography fostered structural determination of materials and greatly facilitated the development of modern science and technology in the past century. However, it is only applied to crystalline structures and cannot resolve noncrystalline materials. Here we demonstrate a novel lensless Fourier-transform ghost imaging method with pseudothermal hard x rays tha...