Professor Riina Aava’s research group works in the field of supramolecular chemistry, which studies how molecules communicate and interact with one another beyond the level of individual covalent bonds. The group focuses on the synthesis of asymmetric container and host molecules and on their characterization at both the molecular and supramolecular levels. Supramolecular chemistry approaches the study of matter in a comprehensive way, integrating aspects of analytical, organic, and physical chemistry. The research explores the formation, structures, and properties of molecules in order to harness these molecules and their interactions for the development of specific and selective receptors and molecular machines. In particular, the group is fascinated by chiral molecules, as the building blocks of living systems are chiral and understanding their properties is essential for understanding how life functions.
The synthesized macrocycles act as molecular containers that bind smaller molecules or ions through intermolecular interactions, with their ability to self-organize being a particularly interesting feature. These macrocycles can be imagined as small barrels without bottoms or lids, in which guest molecules remain inside not because of gravity, but due to electrostatic interactions and geometric complementarity. In the synthesis of hemicucurbiturils—widely used in the group’s laboratory—up to 16 carbon–nitrogen bonds are formed in a single synthetic step, made possible by directed molecular self-organization.
Due to their selectivity and specificity, these molecular containers have potential applications in materials science, as sensors or molecular traps, and in the targeted transport of small molecules, for example in the pharmaceutical and food industries.
The laboratory employs a variety of synthetic techniques, including both traditional solution-based synthesis and mechanochemical synthesis, the latter being more environmentally friendly compared to conventional methods. To study the properties of the synthesized compounds, the group uses high-performance liquid chromatography (HPLC), mass spectrometry (MS), nuclear magnetic resonance (NMR) spectroscopy, ultraviolet–visible (UV–Vis) spectroscopy, single-crystal X-ray diffraction (SC-XRD), and other analytical methods.
Topics:
- Supramolecular receptors for sensing and separation
- Mechanochemical Organic Synthesis
Starting and ongoing projects:
1. HORIZON-HLTH-2021-IND-07, 101057286 IMPACTIVE "Innovative Mechanochemical Processes to synthesize green ACTIVE pharmaceutical ingredients." (2022 - 2026)
2. COST CA22131 - Supramolecular Luminescent Chemosensors for Environmental Security (LUCES) (2023-2027)
3. ÕUF17 The separation, processing, and recycling of rare earth metals (2023–2029)
4. Estonian Research council, PRG2169, "Self-assembled Chiral Hemicucurbiturils as a Versatile Platform for Supramolecular Sensing and Separation of Chiral Compounds (2024−2028)
5. TK228 Centre of Excellence in Circular Economy for Strategic Mineral and Carbon Resources (2024–2030)