Azulene, a non-alternant aromatic hydrocarbon with distinctive electronic and structural characteristics, represents an attractive candidate for ligand design, particularly for complexation of silver ions (Ag⁺). This study focuses on the preparation, characterization, and computational modeling of silver complexes formed by azulene-based Schiff bases. Utilizing Density Functional Theory (DFT), we aim to gain a deeper understanding of their properties. Computational methods provide insights into the electronic structure and stability of these complexes, paving the way for innovative material design and applications in sustainable chemistry. Moreover, the unique electronic configuration of azulene contributes to the enhanced interaction with silver ions, which could lead to the development of advanced catalytic systems and electronic devices. The synthesis of these complexes involves the careful selection of azulene derivatives, optimizing conditions to promote effective Schiff base formation. Characterization techniques such as X-ray crystallography, UV-Vis spectroscopy, and NMR analysis are employed to confirm the structure and purity of the complexes. This comprehensive approach not only elucidates the fundamental aspects of silver-azulene interactions but also explores their potential practical applications in areas such  as gas storage.

Asknowledgment: This study was performed within RO-MD Project: "Redox-active organic and metal-organic cages with azulene derivatives for crystalline engineering" (AZMETCA) Nr. PN-IV-P8-8.3-ROMD-2023-0045, and Moldovan National Project Nr. 010603.

The search for crystalline molecular materials showing interesting and technologically useful properties is one of the most important challenges of crystal engineering. All the synthetic approaches leading to such systems rely on the directionality of the interactions connecting the building-blocks. Apart from the coordination bonds, largely employed to construct molecular solids, other interactions can be useful too: hydrogen and halogen bonds (both directional), metallophilic, and p-p stacking interactions. We currently design new solid-state architectures resulting from the convolution of coordinative and non-covalent interactions. A special emphasis is given to systems containing two different metal ions, as well as to co-crystallization processes. An alternative way towards nanoporous crystals, resulting from the packing of discrete molecules, is discussed. Overall, the integration of various types of interactions—coordinative, hydrogen and halogen bonds, metallophilic, and π–π stacking—provides a versatile toolkit for the rational design of advanced crystalline materials. These materials hold great promise for a wide range of technological applications, from molecular electronics to environmental remediation.

Asknowledgment: This study was performed within RO-MD Project: "Redox-active organic and metal-organic cages with azulene derivatives for crystalline engineering" (AZMETCA) Nr. PN-IV-P8-8.3-ROMD-2023-0045, and Moldovan National Project Nr. 010603.