• azole
• chirality
• circular dichroism
• circularly polarised luminescence
• direct arylation
• Knoevenagel
• metal organic frameworks

Aryl-Azole units are widely diffuse in natural substances as well as synthetic products; these molecules are constituted by an azole core which can be decorated with one, two, three or more aryl units, variously substituted. The resulting π-conjugated system can lend interesting optical properties to these compounds, such as bright colour and fluorescence, both in solution and solid phase. Furthermore, these compounds can show several optical and electronic features which make them very interesting in numerous applications of material chemistry. In addition, with the growth of cross coupling chemistry, such as Suzuki, Negishi, Stille and direct arylation reactions, many efficient procedures have been developed for the synthesis of these classes of compounds, making them even more attractive.
In view of this, during the present Thesis work, two families of 2,5-diaryl azole compounds (in particular, N-substituted Imidazoles, Thiazoles, Oxazoles) are prepared. Specifically, the first class of molecules consists in 2,5-diaryl azoles doubly condensed with cyano-ester moieties; the aryl-azole cores are obtained through a one-pot two-steps double direct arylation reaction between 4-bromobezaldehyde and the appropriate azole leads to the diaryl azole intermediate. Successively, a Knoevenagel reaction between the aldehyde functionalities, of the above intermediate, and β-citronellol-cyanoacetic ester, building block characterised by a chiral centre, is carried out, to obtain the target compounds with a yield of 65-79 %. Spectroscopic characterisations are then performed, both in solution and in solid state (in this latter case, thin films are used; these are obtained through two different deposition techniques, namely Spin Coating and Drop Casting). Initially, UV-Vis absorption, Fluorescence, Circular Dichroism and Quantum Yields are determined for the solutions of the chiral molecules in dichloromethane, giving comparable results for all the compounds: absorption peaks near 400 nm, emission peaks around 500 nm and silent circular dichroism are obtained. Successively, CD (Circular Dichroism) and CPL (Circularly Polarised Luminescence) studies are carried using the compounds in state of thin films, obtaining CD intensities in the range of 800-4000 mdeg and strong CPL signals. Chirality represents a valid tool in the development of innovative technological applications, like detecting or producing circularly polarized light, as well as in the detection of supramolecular organisations.
The second group of compounds prepared in the present work, is represented by 2,5-diarylated azoles bearing two carboxylic groups on the aromatic rings. Again, the aryl-azole moiety is obtained though a double direct arylation reaction, in this case between ethyl 4-bromo-benzoate and the appropriate azole. Then, a further saponification step in acidic or basic conditions is used, in order to convert the ester functionalities in the desired carboxylic groups. Once these compounds are obtained (Yields 26-56%), they are used for the synthesis of several Zirconium (IV) and Aluminium (III) - based MOFs (Metal Organic Frameworks), namely porous materials able to include small molecules, of great interest in numerous technological applications. Finally, the resulting compounds are characterised through XRD analyses, which reveal a certain grade of crystallinity of some of those compounds. Moreover, a reduction of 31% of the material weight after heating in oven (T = 120°C), highlights a certain grade of porosity.