Elucidation of the structure and function of biomolecules provides us knowledge that can be transferred into the generation of new materials and eventually applications in e.g., catalysis or bioassays. The main problems, however, concern the complexity of the natural systems and their limited availability, which necessitates utilization of simple biomimetic analogues that are, to a certain degree, similar in terms of structure and thus behaviour. We have, therefore, devised a small library of six tridentate N-heterocyclic coordinating agents (L¹–L⁶), which, upon complexation, form two groups of artificial, monometallic non-heme iron species. Utilization of iron(III) chloride leads to the formation of the 1:1 (Fe:L_n) ‘open’ complexes, whereas iron(II) trifluoromethanosulfonate allows for the synthesis of 1:2 (M:L_n) ‘closed’ systems. The structural differences between the individual complexes are a result of the information encoded within the metallic centre and the chosen counterion, whereas the organic scaffold influences the observed properties. Indeed, the number and nature of the external hydrogen bond donors coming from the presence of (benz)imidazole moieties in the ligand framework are responsible for the observed biological behaviour in terms of mimicking phenoxazinone synthase activity and interaction with DNA.

Generation of well-defined organic–inorganic hybrid materials with controllable size and morphology is challenging and an active area of modern research in view of their unique properties and thus multifunctional applications. Specifically polyoxometalates (POMs) were recognized as a very promising group for the construction of those systems, nonetheless there are domains where the profound understanding of hierarchical mutual interactions and assembly are lacking. We present an efficient approach towards the synthesis of a novel group of POM-based nanocomposites that we name Complex-Decorated Surfactant Encapsulated-Clusters (CD-SECs). In the investigated system the organic surfactant may behave as a metal-coordinating agent, thus allowing for derivatization of the synthesized SECs via utilization of the non-covalent interactions. We demonstrate possibilities and limitations of three types of hybrid systems (H1–H3) generated via seven distinct constructing approaches (routes A–G). These systems have the potential to exhibit multiresponsive functions depending on the nature of their building blocks and could find many potential applications in biology or materials science.

The reaction of Fe(iii) ions with a terpyridine ligand L in the presence of chlorides and independent of conditions results in the formation of μ-oxo bridged dinuclear [FeLCl(μ-O)FeCl₃] and the mononuclear complex [FeLCl₂].