Templating Porphyrin Anisotropy via Magnetically Aligned Carbon Nanotubes

Applications of Photoinduced Phenomena in Supramolecularly Arranged Phthalocyanine Derivatives: A Perspective

This review focuses on the description of several examples of supramolecular assemblies of phthalocyanine derivatives differently functionalized and interfaced with diverse kinds of chemical species for photo-induced phenomena applications. In fact, the role of different substituents was investigated in order to tune peculiar aggregates formation as well as, with the same aim, the possibility to interface these derivatives with other molecular species, as electron donor and acceptor, carbon allotropes, cyclodextrins, protein cages, drugs. Phthalocyanine photo-physical features are indeed really interesting and appealing but need to be preserved and optimized. Here, we highlight that the supramolecular approach is a versatile method to build up very complex and functional architectures. Further, the possibility to minimize the organization energy and to facilitate the spontaneous assembly of the molecules, in numerous examples, has been demonstrated to be more useful and performing than the covalent approach.

Self-assembly and spectroscopic fingerprints of photoactive pyrenyl tectons on hBN/Cu(111)

The controlled modification of electronic and photophysical properties of polycyclic aromatic hydrocarbons by chemical functionalization, adsorption on solid supports, and supramolecular organization is the key to optimize the application of these compounds in (opto)electronic devices. Here, we present a multimethod study comprehensively characterizing a family of pyridin-4-ylethynyl-functionalized pyrene derivatives in different environments. UV-vis measurements in toluene solutions revealed absorption at wavelengths consistent with density functional theory (DFT) calculations, while emission experiments showed a high fluorescence quantum yield. Scanning tunneling microscopy (STM) and spectroscopy (STS) measurements of the pyrene derivatives adsorbed on a Cu(111)-supported hexagonal boron nitride (hBN) decoupling layer provided access to spatially and energetically resolved molecular electronic states. We demonstrate that the pyrene electronic gap is reduced with an increasing number of substituents. Furthermore, we discuss the influence of template-induced gating and supramolecular organization on the energies of distinct molecular orbitals. The selection of the number and positioning of the pyridyl termini in tetrasubstituted, trans- and cis-like-disubstituted derivatives governed the self-assembly of the pyrenyl core on the nanostructured hBN support, affording dense-packed arrays and intricate porous networks featuring a kagome lattice.

Design, Synthesis, and Functionalization Strategies of Tailored Carbon Nanodots

Over the past decades, considerable efforts have been devoted to synthesizing nanostructured materials with specific properties that ultimately shape their function. In the carbon nanotechnology era, for nanomaterials such as fullerenes, carbon nanotubes, and graphene, the main focus has been on the organic functionalization of these nanostructures, in order to tailor their processability and applicability. Carbon-based dots, quasi-spherical nanoparticles with a shape under 10 nm, have popped up into this context especially due to their versatile synthesis and intriguing properties, mainly their fluorescence emission. Even though they were discovered through the top-down route of cutting large carbon nanostructures, in recent years the ease and flexibility of the bottom-up synthesis have allowed this carbon-based class of nanomaterials to advance at a striking pace. However, the fast speed of research and publication rate have caused a few issues that affect their classification, purity criteria, and fluorescence mechanisms. As these are being progressively addressed, the true potential and applicability of this nanomaterial has started to unravel. In this Ariticle, we describe our efforts toward the synthesis, purification, characterization, and applications of carbon nanodots. Special attention was dedicated to designing and customizing the optoelectronic properties of these nanomaterials, as well as their applications in hybrid and composite systems. Our approach is centered on a bottom-up, microwave-assisted hydrothermal synthesis. We have successfully exploited a multicomponent synthetic approach, using arginine and ethylenediamine as starting materials. By controlling the reaction conditions, in just 3 min, blue-emitting carbon nanodots become accessible. We have improved this approach by designing and tuning the emissive, electrochemical, and chiroptical properties of these nanoforms. On the other hand, we have used postfunctionalization reactions as a tool for conjugation with suitable partners and for further tuning the surface chemistry. The combination of these two approaches has produced a number of carbon nanodots that can be investigated in fields ranging from biology to materials chemistry and in applications spanning from nanomedicine to energy conversion.