Lanthanide Doped Complexes and Organometallic Clusters: Design Strategies and their Applications in Biology and Photonics

2019 ◽  
Vol 9 (3) ◽  
pp. 166-217 ◽  
Author(s):  
Gangadharan A. Kumar

In this review, we discuss the rational design of a new class of lanthanide-doped organometallic nanostructured materials called `molecular minerals`. Molecular minerals are nanostructured materials with a ceramic core made from chalcogenide groups and other heavy metals. Part of the central core atoms is replaced by suitable lanthanide atoms to impart fluorescent spectral properties. The ceramic core is surrounded by various types of organic networks thus making the structure partly ceramic and organic. The central core has superior optical properties and the surrounding organic ligand makes it easy to dissolve several kinds of organic solvents and fluoropolymers to make several kinds of active and passive photonic devices. This chapter starts with elaborate design strategies of lanthanidebased near-infrared emitting materials followed by the experimental results of selected near-infrared emitting lanthanide clusters. Finally, their potential applications in telecommunication, light-emitting diodes and medical imaging are discussed.

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 155
Author(s):  
Jian-Xun Liu ◽  
Shi-Lin Mei ◽  
Xian-He Chen ◽  
Chang-Jiang Yao

Near-infrared (NIR) emissive metal complexes have shown potential applications in optical communication, chemosensors, bioimaging, and laser and organic light-emitting diodes (OLEDs) due to their structural tunability and luminescence stability. Among them, complexes with bridging ligands that exhibit unique emission behavior have attracted extensive interests in recent years. The target performance can be easily achieved by NIR light-emitting metal complexes with bridging ligands through molecular structure design. In this review, the luminescence mechanism and design strategies of NIR luminescent metal complexes with bridging ligands are described firstly, and then summarize the recent advance of NIR luminescent metal complexes with bridging ligands in the fields of electroluminescence and biosensing/bioimaging. Finally, the development trend of NIR luminescent metal complexes with bridging ligands are proposed, which shows an attractive prospect in the field of photophysical and photochemical materials.


2015 ◽  
Vol 3 (10) ◽  
pp. 2244-2254 ◽  
Author(s):  
Li-Ming Yang ◽  
Eric Ganz ◽  
Song Wang ◽  
Xiao-Jun Li ◽  
Thomas Frauenheim

We propose a new series of covalent–organic frameworks. These materials have narrow band gaps, leading to strong near infrared optical response. Density functional theory calculations are used to explore their properties. These novel infrared active materials may have potential applications in organic light-emitting devices, chemical and biological sensing, hybrid solar cells, or electroluminescence.


2009 ◽  
Vol 1154 ◽  
Author(s):  
Yixing Yang ◽  
Richard Farley ◽  
Timothy Steckler ◽  
Jonathan Sommer ◽  
Sang Hyun Eom ◽  
...  

AbstractOrganic light-emitting devices (OLEDs) emitting near-infrared (NIR) light have many potential applications, yet the efficiency of these devices remains very low, typically ˜0.1% or less. Here we report efficiency NIR OLEDs based on two fluorescent donor-acceptor-donor oligomers and a phosphorescent Pt-containing organometallic complex. External quantum efficiencies in the range of 0.5–3.8% with emission peak ranging from 700 to 890 nm have been achieved.


2021 ◽  
Vol 8 ◽  
Author(s):  
Partha Kumbhakar ◽  
Chinmayee Chowde Gowda ◽  
Chandra Sekhar Tiwary

In the last several decades, significant efforts have been devoted to two-dimensional (2D) materials on account of their optical properties that have numerous applications in the optoelectronic world in the range of light-emitting diodes, optical sensors, solar energy conversion, photo-electrochemical cells, photovoltaic solar cells, and even the biomedical sector. First, we provide an outline of linear optical properties of 2D materials such as graphene, TMDs, h-BN, MXenes, perovskite oxide, and metal-organic framework. Then, we discuss the optoelectronic properties of the 2D materials. Along with these, we also highlight the important efforts in developing 2D optical materials with intensive emission properties at a broad wavelength from ultraviolet to near-infrared. The origin of this tunable emission has been discussed decoratively. Thickness and layer-dependent optical properties have been highlighted and are explained through surface defects, strain, vacancy, doping, and dangling bonds emerging due to structural change in the material. The linear and nonlinear optical properties in 2D MXene and perovskite oxides are also impressive due to their potential applications in next-generation devices with excellent optical sensitivity. Finally, technological innovations, challenges, and possible tuning of defects and imperfections in the 2D lattice are discussed.


2020 ◽  
Author(s):  
Yunzhong Wang ◽  
Saixing Tang ◽  
Yating Wen ◽  
Shuyuan Zheng ◽  
Bing Yang ◽  
...  

<div>Persistent room-temperature phosphorescence (p-RTP) from pure organics is attractive </div><div>due to its fundamental importance and potential applications in molecular imaging, </div><div>sensing, encryption, anticounterfeiting, etc.1-4 Recently, efforts have been also made in </div><div>obtaining color-tunable p-RTP in aromatic phosphors5 and nonconjugated polymers6,7. </div><div>The origin of color-tunable p-RTP and the rational design of such luminogens, </div><div>particularly those with explicit structure and molecular packing, remain challenging. </div><div>Noteworthily, nonconventional luminophores without significant conjugations generally </div><div>possess excitation-dependent photoluminescence (PL) because of the coexistence of </div><div>diverse clustered chromophores6,8, which strongly implicates the possibility to achieve </div><div>color-tunable p-RTP from their molecular crystals assisted by effective intermolecular </div><div>interactions. Here, inspirited by the highly stable double-helix structure and multiple </div><div>hydrogen bonds in DNA, we reported a series of nonconventional luminophores based on </div><div>hydantoin (HA), which demonstrate excitation-dependent PL and color-tunable p-RTP </div><div>from sky-blue to yellowish-green, accompanying unprecedentedly high PL and p-RTP </div><div>efficiencies of up to 87.5% and 21.8%, respectively. Meanwhile, the p-RTP emissions are </div><div>resistant to vigorous mechanical grinding, with lifetimes of up to 1.74 s. Such robust, </div><div>color-tunable and highly efficient p-RTP render the luminophores promising for varying </div><div>applications. These findings provide mechanism insights into the origin of color-tunable </div><div>p-RTP, and surely advance the exploitation of efficient nonconventional luminophores.</div>


2020 ◽  
Author(s):  
Alex Stafford ◽  
Dowon Ahn ◽  
Emily Raulerson ◽  
Kun-You Chung ◽  
Kaihong Sun ◽  
...  

Driving rapid polymerizations with visible to near-infrared (NIR) light will enable nascent technologies in the emerging fields of bio- and composite-printing. However, current photopolymerization strategies are limited by long reaction times, high light intensities, and/or large catalyst loadings. Improving efficiency remains elusive without a comprehensive, mechanistic evaluation of photocatalysis to better understand how composition relates to polymerization metrics. With this objective in mind, a series of methine- and aza-bridged boron dipyrromethene (BODIPY) derivatives were synthesized and systematically characterized to elucidate key structure-property relationships that facilitate efficient photopolymerization driven by visible to NIR light. For both BODIPY scaffolds, halogenation was shown as a general method to increase polymerization rate, quantitatively characterized using a custom real-time infrared spectroscopy setup. Furthermore, a combination of steady-state emission quenching experiments, electronic structure calculations, and ultrafast transient absorption revealed that efficient intersystem crossing to the lowest excited triplet state upon halogenation was a key mechanistic step to achieving rapid photopolymerization reactions. Unprecedented polymerization rates were achieved with extremely low light intensities (< 1 mW/cm<sup>2</sup>) and catalyst loadings (< 50 μM), exemplified by reaction completion within 60 seconds of irradiation using green, red, and NIR light-emitting diodes.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Yusaku Hontani ◽  
Mikhail Baloban ◽  
Francisco Velazquez Escobar ◽  
Swetta A. Jansen ◽  
Daria M. Shcherbakova ◽  
...  

AbstractNear-infrared fluorescent proteins (NIR FPs) engineered from bacterial phytochromes are widely used for structural and functional deep-tissue imaging in vivo. To fluoresce, NIR FPs covalently bind a chromophore, such as biliverdin IXa tetrapyrrole. The efficiency of biliverdin binding directly affects the fluorescence properties, rendering understanding of its molecular mechanism of major importance. miRFP proteins constitute a family of bright monomeric NIR FPs that comprise a Per-ARNT-Sim (PAS) and cGMP-specific phosphodiesterases - Adenylyl cyclases - FhlA (GAF) domain. Here, we structurally analyze biliverdin binding to miRFPs in real time using time-resolved stimulated Raman spectroscopy and quantum mechanics/molecular mechanics (QM/MM) calculations. Biliverdin undergoes isomerization, localization to its binding pocket, and pyrrolenine nitrogen protonation in <1 min, followed by hydrogen bond rearrangement in ~2 min. The covalent attachment to a cysteine in the GAF domain was detected in 4.3 min and 19 min in miRFP670 and its C20A mutant, respectively. In miRFP670, a second C–S covalent bond formation to a cysteine in the PAS domain occurred in 14 min, providing a rigid tetrapyrrole structure with high brightness. Our findings provide insights for the rational design of NIR FPs and a novel method to assess cofactor binding to light-sensitive proteins.


2021 ◽  
Vol 23 (12) ◽  
pp. 7495-7503
Author(s):  
Wanlin Cai ◽  
Kai Ren ◽  
Ancong Zhao ◽  
Xiulan Wu ◽  
Rongxing He ◽  
...  

Compared to the PtOO7-based system, the greater EQE of the PtON7-based system is mainly governed by the stronger energy transfer efficiency (ηEET); thus, it is necessary to evaluate ηEET from hosts to guests for the rational design of OLEDs.


2021 ◽  
Vol 9 (36) ◽  
pp. 12068-12072
Author(s):  
Wentao Li ◽  
Jiaxiang Liu ◽  
Baowen Wang ◽  
Siyu Hou ◽  
Xingqiang Lü ◽  
...  

Based on geometrical isomerisation of [Ir(C^N1)(C^N2)((N^O))]-tris-heteroleptic Ir(iii)-complexes, the augmented transition dipole transition (TMD) with a preferential horizontal orientation, which is beneficial for their NIR-phosphorescence, is reported.


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