## 1 Introduction  
Coordination complexes based on d-block metal centres are considered as promising molecular materials for bringing important advancements in applicative fields, such as opto-electronics, photonics, data storage, catalysis, biomedicine, etc., due to unique features imparted by the different nature of the molecular fragments, which, when combined together, contribute to the collective properties of the final material [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]. The redox, magnetic, optical, catalytic, electrical or electrochemical properties of the d-block metal ion centre can cooperatively interact with those of the organic ligands (redox, optic, biologic properties) and/or counterions (solubility in polar solvents, anion coordination) in the case of ionic species, to enhance or modify the overall properties of the architectural ensemble [11, 12, 13, 14, 15, 16, 17, 18, 19]. Indeed, the properties of a d-block-based metal coordination complex are more than the sum of the individual component's properties, and in many cases, synergistic unique physicochemical properties may be engineered this way [4; 5; 20], while the supramolecular arrangement is important due to the sensitivity of the coordination complex to the molecular surroundings, particularly for emission properties [21; 22]. Thus, different soft or crystalline supramolecular architectures built up with the same \"d-block metal containing building block\" through non-covalent interactions can have varied photophysical properties, and small changes in their molecular structure may induce a huge modification of the materials response to external stimuli [5; 15; 16; 21; 22]. Zn(II)-based metallomesogens were mainly designed for application in electro-optics, due to the possibility of obtaining luminescent polarized emission [23; 24; 25; 26; 27; 28]. Recently, a series of pentacoordinated Zn(II) coordination complexes (**Zn_1-4** in Figure 1) self-assembling into 2D hexagonal columnar and 3D mesophases was reported [27; 28]. The symmetry of the mesophases was somehow expected taking into account the bulky coordination sphere around the Zn(II) ion fulfilled by a tridentate chelating N'N'N tperpyridine (tpy) ligand differently substituted in apical position and two monoanionic gallate-based ligands. Indeed, the majority of tetra-, penta- and hexa-coordinated Zn(II) derivatives displayed columnar mesophases [24; 25; 26; 27; 28; 29; 30; 31; 32; 33; 34]; however, some smectic phases [23; 35; 36; 37; 38] or lamello-columnar phases were also reported [39]. The monoanionic ligands decorated with several long alkyl chains were responsible for the induction of liquid crystalline properties, while the terypyridine-based substituents (\(-\)C\({}_{6}\)H\({}_{4}\)R, Figure 1) influenced the supramolecular arrangement by the modification of the interface between antagonistic aromatic and alkyl chains segments and were the determining factor for the photophysical properties: the electron-donating -NE\({}_{2}\) group originated an ILCT excited state and **Zn_2** reaching a record luminescence quantum yield in solution (95%). In electrochemical sensing, the presence of a d-block metal centre brings redox properties, while the organic ligands may act as a separator of the metal centres avoiding close contacts and implicit agglomeration; the separation of the redox active centres may yield micro or even nano-electrode arrays/assemblies, increasing the sensing performances, especially for bioanalysis devices [40; 41; 42]. The electrocatalytic activities of various forms of zinc oxides have been studied for multiple applications, e.g., the oxygen reduction (ORR) reaction that play an important role in renewable energy technologies [43; 44], water electrooxidation for the generation of hydrogen peroxide [45] and for electrochemical sensing of various biologically active compounds [46; 47].