Combined experimental and theoretical investigations on the encapsulation of nickel(<scp>ii</scp>)tet-a complex in zeolite Y and its photocatalytic activity

Photocatalytic mechanism of the 5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane [tet-a] nickel(ii) encapsulated in zeolite Y.</p

Investigation on Fluorescence Origin and Spectral Heterogeneity in Carbon Dots: A Dynamic Perspective

International audienceAbstract Heterogeneity in the fluorescence of carbon dots (CDs) has been hard to figure out so far. This could potentially be related to structural factors, size or intermediate fluorophores, especially when employing the bottom‐up synthesis. Herein, we unveil the origin of fluorescence and spectral heterogeneity of CDs using a simple dynamic method. This work reports the room light‐excited green fluorescence and dual‐emissive N‐doped CDs synthesized using a hydrothermal method. Studies were carried out considering the factors of fluorescence phenomena, such as excitation‐independent emission, fluorescent impurities, aggregation and solvation dynamics. The new steady‐state, Excitation‐resolved area‐normalized emission spectroscopy (ERANES) and ensemble measurements, including time‐resolved studies reveal that a heterogeneous environment exists in the ground state. Eventually, the results show the existence of core, edge and surface states in the CDs. Additionally, the fluorescence characteristics depend on the structural functionalization that occurs in both the intrinsic and extrinsic states of the CDs and it is proven that this does not violate the Kasha‐Vavilov rule. Although a highly purified material could still exhibit heterogeneity due to the ensemble emissive states and structural variations. Our results provide insights into the enduring debates about fluorescence and a deeper understanding of the structure‐ property relationship of CDs

Facile Fabrication of Carbon Dots based Fluorescent Strips for Florimetric ON-OFF Sensor

International audienceCarbon dots (CDs) are an emerging smart material that is applied in a wide range of applications including sensors, photocatalysis, bioimaging, and optoelectronic devices. In recent decades, CDs have been an alternative to semiconductor-based quantum dots due to their unique optical properties. CDs are highly fluorescent, zero in dimensional (<10 nm), sp2 and sp3 hybridized carbon core with highly surface-functionalized nanomaterials. While thousands of studies have already been published, carbon dot research is still emerging due to its unique structural and photoluminescent properties. Herein, we report a synthesis of highly fluorescent, amphiphilic, solid-state yellow luminescent, dual emissive carbon dots and their fabrication as strip probes for metal ion sensing. Remarkably, a simple tuning of the stoichiometric ratio of precursors leads to solid-state yellow luminescent and dual emissive CDs. In addition, we investigated, how nitrogen speciation, graphitization and surface functionality of carbon dots (CDs) can impact the structure-optical property relationship of CDs in solution and solid-state. We fabricated CDs-based fluorescent strips and utilized them as an ON-OFF fluorescence sensor to detect Hg2+ metal ions in an aqueous medium with great sensitivity and selectivity. These results would give an approach for tuning the fluorescence and structural characteristics of CDs to develop a simple strip-based probe without a self-quenching issue for sensor applications

Encapsulation of a hexaaza macrocyclic nickel(<scp>ii</scp>) complex in zeolite Y: an experimental and theoretical investigation

In this study, a 1,8-dimethyl-1,3,6,8,10,13-hexaazacyclotetradecane nickel(ii) complex was encapsulated in the supercages of zeolite Y for the photocatalytic removal of methylene blue under visible light.</p

Tetraammine(carbonato-&#954;2O,O&#8242;)cobalt(III) perchlorate

In the title complex, [Co(CO3)(NH3)4]ClO4, both the cation and anion lie on a mirror plane. The CoIII ion is coordinated by two NH3 ligands and a chelating carbonato ligand in the equatorial sites and by two NH3 groups in the axial sites, forming a distorted octahedral geometry. In the crystal, N&#8212;H...O hydrogen bonds connect the anions and cations, forming a three-dimensional network