Small molecule single crystal X-ray diffraction studies at the MX2 beamline of the LNLS: crystal engineering of organic molecules and coordination compounds with relevance to material science

FLORENCIA DI SALVO; FEDERICO MOVILLA; JUAN MANUEL REY; ANDREA PAOLA RIVAS MARQUINA; CRISTIÁN HUCK IRIART

Campinas

Conferencia; 29. RAU: annual users meeting LNLS/CNPEM; 2019

Crystal engineering is a discipline that has as main interests the design and synthesis of crystalline solidswith a particular purpose and specific properties [1]. Thus, as a starting point, it is essential to perform highquality single crystal X-ray diffraction studies that conduct successfully to the determination of the molecularand supramolecular structure of the studied systems. The instrumental limitations of laboratory single crystalX-ray diffractometers restrict significantly the projects related with crystal engineering and structuralchemistry. Data collection at a storage-ring synchrotron source opened new possibilities for crystal structuredeterminations bringing enormous advantages for fields related to small molecules building blocks, likecrystal engineering, as well as chemical and materials science areas in general [2]. In this work we willpresent the single crystal X-ray diffraction structural studies of several small molecule systems performedby the data obtained using the MX2 beamline of the LNLS. We were able to successfully determine thestructure of several members of the following systems: a) organic molecules which are able to act as buildingblocks for the construction of different materials such as, supramolecular gels and mesocrystals; b)mononuclear and polynuclear coordination compounds and c) coordination polymers (CP). The coordinationsystems included in b) and c) were mainly synthetized using the molecules mentioned in a), as ligands. Inall cases the information obtained contributed to unequivocally confirm their molecular structure and studytheir supramolecular characteristics and properties. These results were also fundamental to analyse the roleof the structural features and intermolecular interactions in the crystal packing and also, in the physical andchemical properties. Regarding the compounds included in system a), new chiral molecules derived fromamino acids and platforms like aldehydes were synthesized in our group for the development of differenttype of materials such as, supramolecular gels [3] and mesocrystals, a fascinating class of crystallinenanostructured materials [4]. With the data obtained from the MX2 beamline, it was possible to study thesingle crystals of several amino acid derivatives and successfully determine their structure with excellentresolution. These results contributed to the understanding of the mechanism related to the gel formation andmesocrystals aggregation. On the other hand, some of these molecules were used as ligands for thesynthesis of coordination compounds ?systems b) and c)?, exhibiting different physical and chemicalproperties. For instance, with the data collected at the LNLS it was possible to determine the X-ray diffractionstructure of a trinuclear Ni(II) complex based on a L-Tyrosine derivative, several mononuclear amino-acidbased Cu(II) monocuclear complexes and 1D Cd(II) and Co(II) coordination polymers. Finally, some of thephysical and chemical properties of these coordination compounds are also discussed in term of theirstructural features.