Single-crystal X-ray diffraction is undoubtedly the most powerful technique for the complete structural elucidation of molecules.
The X-ray Diffraction facility located at the Chemistry Department of FCT-NOVA provides a Crystallography Service for the determination of the three-dimensional structure of small molecules with options varying from unit cell parameters and space group only to complete data collection and structure determination (including absolute configuration determination).
Crystals are evaluated under the polarizing microscope and selected if suitable for X-ray data collection and structural analysis. The screening, testing and complete data collection from X-ray diffraction of single crystals is performed in the in-house X-ray equipment.
The facility is equipped with a Bruker D8 VENTURE with KAPPA four-circle goniometer, dual source X-ray generator (copper and molybdenum microfocus X-ray sources), a Photon 100 CMOS detector, and an Oxford cryo-system. This Bruker D8 Venture is the only dual source equipment available in the country, which was acquired through FCT-MCTES funds (RECI/BBB-BEP/0124/2012).
The structure determination X-ray Service is available not only to FCT-NOVA researchers, but also to other National and Foreign Universities, Public and Private Institutes and to Industry and Companies who need general structure determination or other specific experiments.
Structural elucidation is a crucial element of chemical research, and new methods to provide rapid and accurate identification of molecular structure are constantly under development. Nevertheless, the most powerful technique continues to undeniably be single-crystal X-ray diffraction, allowing, in many situations, the detection of unexpected and/or unknown molecules.
Single-crystal X-ray diffraction is quantitative, non-destructive, and the only analytical technique that allows to retrieve the following information:
- Crystal system, space group, lattice parameters
- Exact geometry of the molecule (bond angles, bond lengths, torsion angles)
- Full chemical composition
- Molecular conformation
- Symmetry of molecules
- Thermal vibrations
- Intermolecular interactions (hydrogen bonds, etc.)
- Absolute configuration of chiral centers
- Detection/quantification and elucidation of the molecular structure of target guest molecules encapsulated inside porous hosts
- Temperature dependent phase transfers
Our structure determination Crystallography Service is unique in the Lisbon area.
Single-crystal X-ray diffraction finds applications in all areas that profit from structural elucidation and full molecule characterization. This includes not only academic research, but also industrial research and development activities, especially those related to chemical synthesis, to the pharmaceutical and agrochemical industry, etc..
In the case of chemical synthesis, as a specific example, it is of crucial importance for coordination/organometallic chemists as this is the only analytic technique that provides a clear evidence of the 3D arrangement of atoms around the metal center, in particular if they are dealing with paramagnetic materials.
Department of Chemistry