1,721,028 research outputs found
Transition metal complexes in ECL: Diagnostics and biosensing
No full textThis chapter addresses the main principles, challenges and achievements in ECL using metal complexes. Selected applications in diagnostics and biosensing are described
Dynamic Reconfiguration of Pt(II) Supramolecular Assemblies via Ligand Exchange
No full textSupramolecular chemistry enables molecules to dynamically adapt and reorganize in response to their environment, providing a key route to achieving high levels of structural and functional complexity. This work explores a particular strategy for the dynamic and programmable self-assembly of luminescent platinum(II) complexes via sequential coordination-driven and hierarchical processes. The aggregation behavior and optical properties of square-planar Pt(II) complexes bearing a chromophoric terdentate NNN ligand and exchangeable monodentate ligands are highly dependent on the nature of the ancillary ligand, resulting in morphologically and photophysically distinct supramolecular structures. We demonstrate that these preassembled aggregates undergo dynamic ligand exchange reactions in solution, leading to metastable supramolecular states, including emissive gels, that are accessible exclusively through in situ exchange. Real-time fluorescence microscopy and NMR spectroscopy reveal both homogeneous and heterogeneous exchange pathways, governed by the identity of the initial complex and the incoming ligand. Remarkably, the system exhibits a degree of reversibility and structural memory. These findings establish a framework for stepwise self-assembly that bridges coordination chemistry with noncovalent interactions, offering a versatile platform for designing responsive nanostructures with tailored properties and a step toward adaptive, life-like materials with potential applications in sensing and optoelectronics
Critical Aspects and Challenges in the Design of Small Molecules for Electrochemiluminescence (ECL) Application
Full text linkElectrochemiluminescence (ECL) has gained renewed interest due to the strong parallel development of luminophores in the field of organic light emitting diodes (OLEDs) with which this technique shares several aspects. In this perspective review we discuss the most relevant advances of the past 15 years in the study of organic and organometallic compounds as ECL emitters, by dividing them in three different classes: i) fluorescent emitters, ii) phosphorescent emitters and iii) Thermally Activated Delayed Fluorescence (TADF) emitters; then, water-soluble organic luminophores will be also discussed. We focus on how their design, their photo- and electrochemical properties and, in particular, the nature of the emitter, affect their efficiency in ECL. Regardless of the type of luminophore or the photoluminescence quantum yield (PLQY), the literature converges on the fact that the most determining aspect is the stability of the oxidized/reduced form of the emitter. Even if phosphorescent emitters can show outstanding efficiency, this often requires the absence of oxygen. In the case of TADFs, there is also a strong dependence of photoluminescence both in terms of PLQY and emission energy on the polarity of the media, so compounds, that appear promising in organic solvents, may be very inefficient in aqueous media.In this perspective review, the most relevant progresses obtained in the last 15 years in the study of organic and organometallic luminophores as ECL emitters were discussed. Examples of fluorescent and phosphorescent emitters, Thermally Activated Delayed Fluorescence (TADF) emitters and finally, water-soluble organic luminophore were reported. imag
Chiral Amplification by Self-Assembly of Neutral Luminescent Platinum(II) Complexes
No full textTwo novel enantiomerically pure chiral ligands and the corresponding neutral PtII complexes have been synthetized and characterized. The self-assembly properties of the complexes have been investigated using different morphological and photophysical techniques. The two enantiomeric complexes, 4 a and 4 b, show high tendency to self-assemble into chiral supramolecular aggregates with right (P) and left-handed (M) helical configurations, respectively, as proven by SEM and absorption circular dichroism. The formation of such organized structures is driven by the formation of metallophilic and π–π interactions between spatially close Pt complexes with an enhancement of the chiro-optical properties in the solid state
Multinuclear PtII Complexes : Why Three is Better Than Two to Enhance Photophysical Properties
Full text linkThe self-assembly of platinum complexes is a well-documented process that leads to interesting changes of the photophysical and electrochemical behavior as well as to a change in reactivity of the complexes. However, it is still not clear how many metal units must interact in order to achieve the desired properties of a large assembly. This work aimed to clarify the role of the number of interacting PtII units leading to an enhancement of the spectroscopic properties and how to address inter- versus intramolecular processes. Therefore, a series of neutral multinuclear PtII complexes were synthesized and characterized, and their photophysical properties at different concentration were studied. Going from the monomer to dimers, the growth of a new emission band and the enhancement of the emission properties were observed. Upon increasing the platinum units up to three, the monomeric blue emission could not be detected anymore and a concentration independent bright-yellow/orange emission, due to the establishment of intramolecular metallophilic interactions, was observed
Copper and silver nanowires for CO2 electroreduction
Full text linkCopper and silver nanowires have been extensively investigated as the next generation of transparent conductive electrodes (TCEs) due to their ability to form percolating networks. Recently, they have been exploited as electrocatalysts for CO2 reduction. In this review, we present the most recent advances in this field summarizing different strategies used for the synthesis and functionalization/activation of copper and silver nanowires, as well as, the state of the art of their electrochemical performance with particular emphasis on the effect of the nanowire morphology. Novel perspectives for the development of highly efficient, selective, and stable electrocatalysts for CO2 reduction arise from the translation of NW-based TCEs in this challenging field
Recent advances in phosphorescent Pt (II) complexes featuring metallophilic interactions: Properties and applications
Full text linkSupramolecular weak interactions can be used for preparing functional self-assembled architectures by powerful bottom-up approaches. In particular, when closed-shell metallophilic and π-π interactions between adjacent transition-metal complexes are established, profound changes in compounds' properties are obtained and novel features often achieved. In this Review, the most recent advances in the field of luminescent platinum(II) complexes aggregating through Pt-Pt interactions are highlighted and their potential application in different fields presented and discussed
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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