The purpose of this project is to obtain compounds with special supramolecular properties which may be utilized for the obtaining of molecular machines and other molecular devices. These molecular aggregates which imitate, at molecular level, the behavior at macro scale in the case of some machines or devices used in daily life, will be in the future constitutive elements of some molecular aggregates with complex functions. These tools (supramolecular aggregates) built at molecular level and self-assembled will be important elements for the improving of nanoscience technologies. In this project we intend to obtain and investigate [2], [3], and [4]rotaxanes and pseudorotaxanes, built after an original idea and which may become components of some complex molecular devices (Figure 6).
The general objectives of this project are:

• O1 The design and the synthesis of new mono-, bi- or trimacrocycles with terpyridinic units, some bifurcated and trifurcated axle molecules, and also the synthesis of the corresponding pseudorotaxanes and rotaxanes (obtaining of the macrocyclic derivatives and complementary molecular axles in high yields and in as simple as possible ways; assignment of the steric complementarities between mono- di- and tricyclic derivatives and axle molecules; self-assembly of the molecules in [2], [3], and [4]pseudorotaxanes; attachment of stoppers and obtaining of the corresponding rotaxanes);
• O2 Structural analysis of the obtained macrocycles, pseudorotaxanes and rotaxanes (identification of the pertinent analysis methods and structure determination by NMR, X-Ray diffraction and Mass Spectrometry);
• O3 Determination of the supramolecular properties, complexation capacity and determination of the stability of rotaxanes and pseudorotaxanes;
• O4 Improvement of the laboratory equipments and training of high qualified personnel (PhD students from the research team)
• O5 Results dissemination, by publishing in high impact journals, communications and posters at the Chemistry Congresses and by defending of the PhD theses.

Project manager along with Assist. Elena Bogdan will insure a good development of the project by weekly meetings (reports) with the entire team in which there will be discussions on the results obtained so far, optimal synthetic pathways and a prompt preparation of the material to a fastest publication possible in chemistry journals.
Among the original elements presented in this research project are:

• The design of polytopical macrocyclic systems, of bifurcated and trifurcate axle molecules, of semirotaxanes and rotaxanes.
• Possibility to extend this research towards obtaining molecular devices. For example, by adding a stopper having a longer arm and pyryl units, molecular shuttles may be built, controllable by varying pH. Another extension would be addition of units containing thiol groups instead the stoppers and then anchorage of the whole system onto a gold (111) surface leading to molecular shuttles to be controlled be modification of the potential applied to the gold surface.
• The methods used for investigation of the properties of the obtained macrocyclic systems are original and they include studies by NMR spectroscopy, complexation studies using modern methods of mass spectroscopy (e.g. ESI-MS)
• The synthesis strategy for intermediates and final products is also original