Lanthanide coordination polymers – paving the way for optical properties and related applications
Creators: name: Zheng, Min
Publisher: name: figshare
Year: 2022
Subjects: subject: 30301 Chemical Characterisation of Materials
subject: FOS: Chemical sciences
subject: Crystallography
subject: Inorganic Chemistry
subject: 30204 Main Group Metal Chemistry
subject: 30303 Optical Properties of Materials
subject: 30304 Physical Chemistry of Materials
subject: 30206 Solid State Chemistry
subject: 30202 f-Block Chemistry

description: <b>ABSTRACT</b>Lanthanide coordination polymers have attracted the garnered a lot of scientific scrutiny for a number of years because of their intriguing properties, which range from catalytic, magnetic to optical applications. Particularly Through the use of lanthanide emission, which is found in various areas in the spectrum of electromagnetic radiation, these compounds can be used in a wide range of uses that emit light, including television and smartphone screens, LEDs, optical fibers, and even laser applications (e.g. Nd-YAG laser) among other things. Their unique properties are due to their electronic configuration 4f. But, the ligand as well as environment also play an significant role, which is why the coordination the chemistry of 4f cations is in the process of fast development. Today, because of their demonstrated applications, scientists are focusing on the creation of new species as well as the study of their physicochemical characteristics.<br> <b><br></b><b>MAINTEXT</b> <b>Introduction</b> Coordination polymers constructed from lanthanide ions have captivated the research attention from scientists for a number of years because of their intriguing characteristics, like optical, catalytic and magnetic. Through the use of lanthanide emission, which is found in various areas in the spectrum of electromagnetic radiation they can be utilized in a vast range of uses as emission devices like TV smartphones, LEDs, optical fibers, lasers among other things. Their distinctive properties are due to their electronic configuration arising from 4f electron orbitals. The ligand, as well as its environment (solvents, but also nearest molecules) play an significant role, which is why the coordination the chemistry of 4f cations is developing rapidly. Due to their demonstrated applications, scientists are working on the development of new species as well as the study of their physicochemical characteristics. <b><br></b><b>Optical properties and applications</b> Furthermore, due to their unique properties, lanthanide ions, the lanthanide complexes can be interesting as a platform for use in lighting technology. The lanthanide light emission originates from 4f-4f transitions which are characterized by distinct colors of the ultraviolet from the visible to near-infrared region of the spectrum. Unfortunately, the 4f- 4f transitions are hard to trigger directly in accordance with Laporte's law. One method to overcome this limitation is by employing organic chromophores that act as an antenna that sensitizes the lanthanide particles. Phenantroline compounds are well-known in the field of coordination chemistry for lanthanides and are being studied in the full. They are able to excite virtually all spectra of lanthanide's ions to create pure lanthanide light emission colors and also their processing into more intricate matrices offers an opportunity for a vast array of applications, like lighting, optical temperature sensing and so on. There are also applications that arise from many nonlinear optical properties of coordination polymers, which are second harmonic generation (in the case of noncentrosymmetric structures), third harmonic generation, two photon absorption (2PA) as well as multiphoton absorption. To be useful for nonlinear optical applications, organic chromophores in this instance should be appropriately designed either to serve in the role of antennas harvesting radiation, or to perform structural role such as induction on acentric structure, including chirality. Nevertheless, ligands should be able emit on their own to produce the blue component, if white light emission is needed. The design of these white-light emitting lanthanide compounds is usually built around the combination of organic chromophores that emit in the blue area, and a lanthanide-ion that is emitting in the green (Tb<sup>3+</sup>), yellow (Dy<sup>3+</sup>) or red (Eu<sup>3+</sup>) region. <b><br></b><b>Lanthanide complexes</b> In the various lanthanide(III) types that could be found, mononuclear complexes provide a fascinating area because of the flexibility of lanthanide cations, as well as the wide range of linkers that are able to complete the coordination sphere. In order to ensure effective control over the coordination space the macrocyclic linkers could be a good candidate, because of their multiple binding modes and the chelating characteristics. There are a variety of structures of lanthanide complexes were discovered through the condensing of 2,6-diacetylpyridine as well various diamines. The final coordination number in the compounds is determined through the lanthanide cation as well as the coordinating anions as well as solvent species. However, less information is found for the structural characterization of hexaazamacrocyclic lanthanide complexes, derived from 2,6-perylenedicarbaldehyde and a diamine, and the corresponding correlation with their optical properties. Recently, porous coordination polymers a new kind of crystalline solids are being utilized for elimination and detection of anionic pollutants from water. Their luminescent qualities of coordination polymers are able to be modified by adjusting different organic linkers. To achieve high luminescent detection the ability to select coordination polymers the use of electron-rich aromatic linkers were used to create an coordination polymer-based luminescent sensors, since electron transfer of photoexcited electrons of coordination polymers to the analytes lacking electrons generally results in light emission quenching. <b>Synthetic methods</b><br>Today, hydrothermal, solvent-based and ionothermal methods are most commonly used methods for the creation of solid crystals. However, the limitations to the usage of solvents for instance, low boiling point or the high cost has put a limit in exploring new structures. Thus, innovative strategies for synthetic synthesis are required to prepare crystals coordination polymers that have novel designs and intriguing properties. <br> <br>