Determination of H-Atom Positions in Organic Crystal Structures by NEXAFS Combined with Density Functional Theory: a Study of Two-Component Systems Containing Isonicotinamide.

It is important to be able to identify the precise position of H-atoms in hydrogen bonding interactions to fully understand the effects on the structure and properties of organic crystals. Using a combination of near-edge X-ray absorption fine structure (NEXAFS) spectroscopy and density functional theory (DFT) quantum chemistry calculations, we demonstrate the sensitivity of core-level X-ray spectroscopy to the precise H-atom position within a donor-proton-acceptor system. Exploiting this sensitivity, we then combine the predictive power of DFT with the experimental NEXAFS, confirming the H-atom position identified using single-crystal X-ray diffraction (XRD) techniques more easily than using other H-atom sensitive techniques, such as neutron diffraction.

A comprehensive approach to X-ray crystallography for drug discovery at a synchrotron facility - The example of Diamond Light Source.

A detailed understanding of the interactions between drugs and their targets is crucial to develop the best possible therapeutic agents. Structure-based drug design relies on the availability of high-resolution structures obtained primarily through X-ray crystallography. Collecting and analysing quickly a large quantity of structural data is crucial to accelerate drug discovery pipelines.

Diamond: shedding light on structure-based drug discovery.

Structure-based drug design has become a key tool for the development of novel drugs. The process involves elucidating the three-dimensional structure of the potential drug molecule bound to the target protein that has been identified as playing a key role in the disease state. Using this three-dimensional information facilitates the process of making improvements to the potential drug molecule by highlighting existing and possible new interactions within the binding site.

Hetero-bimetallic complexes involving vanadium(V) and rhenium(VII) centers, connected by unsupported mu-oxido bridge: synthesis, characterization, and redox study.

Heterobimetallic complexes of a vanadium(V) and rhenium(VII) combination connected by a mu-oxido bridge [LVO(mu-O)ReO 3].H 2O [H 2L = N, N'-ethylene bis(salicylideneimine) (H 2salen) and its methoxy derivative] ( 1, 2) are reported. The compounds have been prepared by a single-pot synthesis in which the precursor [V (IV)OL] complexes are allowed to be oxidized aerially in the presence of added perrhenate.

Coordination complexes exhibiting anion...pi interactions: synthesis, structure, and theoretical studies.

The polydentate ligand 2,4,6-tris(dipyridin-2-ylamino)-1,3,5-triazine (dpyatriz) in combination with the Cu(ClO 4) 2/CuX 2 salt mixtures (X (-) = Cl (-), Br (-), or N 3 (-)) leads to the formation of molecular coordination aggregates with formulas [Cu 3Cl 3(dpyatriz) 2](ClO 4) 3 ( 2), [Cu 3Br 3(dpyatriz) 2](ClO 4) 3 ( 3), and [Cu 4(N 3) 4(dpyatriz) 2(DMF) 4(ClO 4) 2](ClO 4) 2 ( 4). These complexes consist of two dpyatriz ligands bridged via coordination to Cu (II) and disposed either face-to-face in an eclipsed manner ( 2 and 3) or parallel and mutually shifted in one direction. The copper ions complete their coordination positions with Cl (-) ( 2), Br (-) ( 3), or N 3 (-), ClO 4 (-), and N, N-dimethylformamide (DMF) ( 4) ligands.