Exciton Coupling and Conformational Changes Impacting the Excited State Properties of Metal Organic Frameworks

In recent years, the photophysical properties of crystalline metal-organic frameworks (MOFs) have become increasingly relevant for their potential application in light-emitting devices, photovoltaics, nonlinear optics and sensing. The availability of high-quality experimental data for such systems makes them ideally suited for a validation of quantum mechanical simulations, aiming at an in-depth atomistic understanding of photophysical phenomena. Here we present a computational DFT study of the absorption and emission characteristics of a Zn-based surface-anchored metal-organic framework (Zn-SURMOF-2) containing anthracenedibenzoic acid (ADB) as linker. Combining band-structure and cluster-based simulations on ADB chromophores in various conformations and aggregation states, we are able to provide a detailed explanation of the experimentally observed photophysical properties of Zn-ADB SURMOF-2: The unexpected (weak) red-shift of the absorption maxima upon incorporating ADB chromophores into SURMOF-2 can be explained by a combination of excitonic coupling effects with conformational changes of the chromophores already in their ground state. As far as the unusually large red-shift of the emission of Zn-ADB SURMOF-2 is concerned, based on our simulations, we attribute it to a modification of the exciton coupling compared to conventional H-aggregates, which results from a relative slip of the centers of neighboring chromophores upon incorporation in Zn-ADB SURMOF-2.

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The nanoscaled metal-organic framework ICR-2 as a carrier of porphyrins for photodynamic therapy

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.9.275 ◽

2018 ◽

Vol 9 ◽

pp. 2960-2967 ◽

Cited By ~ 5

Author(s):

Jan Hynek ◽

Sebastian Jurík ◽

Martina Koncošová ◽

Jaroslav Zelenka ◽

Ivana Křížová ◽

...

Keyword(s):

Inorganic Chemistry ◽

Photodynamic Therapy ◽

Photophysical Properties ◽

Metal Organic Framework ◽

Metal Organic Frameworks ◽

Biological Applications ◽

Nanoparticle Surface ◽

Metal Organic ◽

Unsaturated Metal Sites ◽

First Time

Nanosized porphyrin-containing metal-organic frameworks (MOFs) attract considerable attention as solid-state photosensitizers for biological applications. In this study, we have for the first time synthesised and characterised phosphinate-based MOF nanoparticles, nanoICR-2 (Inorganic Chemistry Rez). We demonstrate that nanoICR-2 can be decorated with anionic 5,10,15,20-tetrakis(4-R-phosphinatophenyl)porphyrins (R = methyl, isopropyl, phenyl) by utilizing unsaturated metal sites on the nanoparticle surface. The use of these porphyrins allows for superior loading of the nanoparticles when compared with commonly used 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin. The nanoICR-2/porphyrin composites retain part of the free porphyrins photophysical properties, while the photodynamic efficacy is strongly affected by the R substituent at the porphyrin phosphinate groups. Thus, phosphinatophenylporphyrin with phenyl substituents has the strongest photodynamic efficacy due to the most efficient cellular uptake.

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Anthracene based metal-organic framework showing efficient angle-dependent polarized emission, luminescent thermometry, and photoelectronic response

Dalton Transactions ◽

10.1039/d1dt04077d ◽

2022 ◽

Author(s):

Ji-Rui Zhang ◽

Hao-Yi Zhang ◽

Jia-hui Guo ◽

Zi-Han Liu ◽

Cheng-Yu Ma ◽

...

Keyword(s):

Light Emitting Diodes ◽

Metal Organic Framework ◽

Metal Organic Frameworks ◽

Biological Imaging ◽

Organic Light Emitting Diodes ◽

Photoelectric Device ◽

Light Emitting ◽

Organic Light ◽

Polarized Emission ◽

Metal Organic

The development of luminescent metal-organic frameworks (MOFs) has attracted extensive attention due to their applications in photoelectric device, organic light-emitting diodes (OLEDs), anti-counterfeiting, biological imaging and so on. In this...

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Eu3+/Tb3+ functionalized Bi-based metal–organic frameworks toward tunable white-light emission and fluorescence sensing applications

Dalton Transactions ◽

10.1039/c8dt03474e ◽

2018 ◽

Vol 47 (46) ◽

pp. 16696-16703 ◽

Cited By ~ 24

Author(s):

Lifei Xu ◽

Yan Xu ◽

Xianliang Li ◽

Zhuopeng Wang ◽

Ting Sun ◽

...

Keyword(s):

White Light ◽

Light Emission ◽

Metal Organic Frameworks ◽

White Light Emission ◽

Fluorescence Sensing ◽

Light Emitting ◽

Light Emitting Devices ◽

Sensing Applications ◽

Metal Organic

Eu3+/Tb3+ singly doped or codoped bismuth-based MOFs were developed to explore white-light emitting devices and construction of supersensitive multifunctional sensors.

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Water-Soluble Metal–Organic Framework Hybrid Electron Injection Layer for Organic Light-Emitting Devices

Journal of Inorganic and Organometallic Polymers and Materials ◽

10.1007/s10904-017-0644-3 ◽

2017 ◽

Vol 27 (6) ◽

pp. 1800-1805 ◽

Cited By ~ 6

Author(s):

Mohammad Janghouri ◽

Hadi Hosseini

Keyword(s):

Metal Organic Framework ◽

Electron Injection ◽

Water Soluble ◽

Light Emitting ◽

Light Emitting Devices ◽

Electron Injection Layer ◽

Organic Light ◽

Metal Organic ◽

Organic Light Emitting Devices ◽

Organic Framework

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Conductive MOFs with Photophysical Properties: Applications and Thin-Film Fabrication

Nano-Micro Letters ◽

10.1007/s40820-020-00470-w ◽

2020 ◽

Vol 12 (1) ◽

Author(s):

Zeyu Zhuang ◽

Dingxin Liu

Keyword(s):

Thin Film ◽

Photophysical Properties ◽

Metal Organic Frameworks ◽

High Quality ◽

Electrically Conductive ◽

Light Emitting ◽

Thin Film Fabrication ◽

Metal Organic ◽

Film Fabrication ◽

Luminescent Sensing

AbstractMetal–organic frameworks (MOFs) are a class of hybrid materials with many promising applications. In recent years, lots of investigations have been oriented toward applications of MOFs in electronic and photoelectronic devices. While many high-quality reviews have focused on synthesis and mechanisms of electrically conductive MOFs, few of them focus on their photophysical properties. Herein, we provide an in-depth review on photoconductive and photoluminescent properties of conductive MOFs together with their corresponding applications in solar cells, luminescent sensing, light emitting, and so forth. For integration of MOFs with practical devices, recent advances in fabrication of photoactive MOF thin films are also summarized.

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Fluorescent Dye-Based Metal–Organic Framework Piezochromic and Multicolor-Emitting Two-Dimensional Materials for Light-Emitting Devices

ACS Applied Nano Materials ◽

10.1021/acsanm.9b00055 ◽

2019 ◽

Vol 2 (3) ◽

pp. 1614-1620 ◽

Cited By ~ 3

Author(s):

Kartik Maity ◽

Devdeep Mukherjee ◽

Mainak Sen ◽

Kumar Biradha

Keyword(s):

Metal Organic Framework ◽

Fluorescent Dye ◽

Two Dimensional ◽

Light Emitting ◽

Light Emitting Devices ◽

Two Dimensional Materials ◽

Metal Organic ◽

Organic Framework

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Magnetic Ordering via Itinerant Ferromagnetism in a Metal-Organic Framework

10.26434/chemrxiv.12330866 ◽

2020 ◽

Author(s):

Jesse Park ◽

Brianna Collins ◽

Lucy Darago ◽

Tomce Runcevski ◽

Michael Aubrey ◽

...

Keyword(s):

Charge Transport ◽

Magnetic Order ◽

Metal Organic Framework ◽

Metal Organic Frameworks ◽

Magnetic Ordering ◽

Double Exchange ◽

Itinerant Ferromagnetism ◽

Organic Solids ◽

Metal Organic ◽

Organic Framework

Materials that combine magnetic order with other desirable physical attributes offer to revolutionize our energy landscape. Indeed, such materials could find transformative applications in spintronics, quantum sensing, low-density magnets, and gas separations. As a result, efforts to design multifunctional magnetic materials have recently moved beyond traditional solid-state materials to metal–organic solids. Among these, metal–organic frameworks in particular bear structures that offer intrinsic porosity, vast chemical and structural programmability, and tunability of electronic properties. Nevertheless, magnetic order within metal–organic frameworks has generally been limited to low temperatures, owing largely to challenges in creating strong magnetic exchange in extended metal–organic solids. Here, we employ the phenomenon of itinerant ferromagnetism to realize magnetic ordering at TC = 225 K in a mixed-valence chromium(II/III) triazolate compound, representing the highest ferromagnetic ordering temperature yet observed in a metal–organic framework. The itinerant ferromagnetism is shown to proceed via a double-exchange mechanism, the first such observation in any metal–organic material. Critically, this mechanism results in variable-temperature conductivity with barrierless charge transport below TC and a large negative magnetoresistance of 23% at 5 K. These observations suggest applications for double-exchange-based coordination solids in the emergent fields of magnetoelectrics and spintronics. Taken together, the insights gleaned from these results are expected to provide a blueprint for the design and synthesis of porous materials with synergistic high-temperature magnetic and charge transport properties.

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Engineering Porosity Through Defects in a Giant Pore Metal–Organic Framework

10.26434/chemrxiv.12847574.v1 ◽

2020 ◽

Author(s):

Adam Sapnik ◽

Duncan Johnstone ◽

Sean M. Collins ◽

Giorgio Divitini ◽

Alice Bumstead ◽

...

Keyword(s):

Distribution Function ◽

Ball Milling ◽

Local Structure ◽

Pair Distribution Function ◽

Function Analysis ◽

Metal Organic Framework ◽

Metal Organic Frameworks ◽

Defect Engineering ◽

Metal Organic ◽

Unsaturated Metal Sites

Defect engineering is a powerful tool that can be used to tailor the properties of metal–organic frameworks (MOFs). Here, we incorporate defects through ball milling to systematically vary the porosity of the giant pore MOF, MIL-100 (Fe). We show that milling leads to the breaking of metal–linker bonds, generating more coordinatively unsaturated metal sites, and ultimately causes amorphisation. Pair distribution function analysis shows the hierarchical local structure is partiallyretained, even in the amorphised material. We find that the solvent toluene stabilises the MIL-100 (Fe) framework against collapse and leads to a substantial rentention of porosity over the non-stabilised material.

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Metal-Organic Frameworks vs. Buffers: Case Study of UiO-66 Stability

10.26434/chemrxiv.12588269.v1 ◽

2020 ◽

Author(s):

Daniel Bůžek ◽

Slavomír Adamec ◽

Kamil Lang ◽

Jan Demel

Keyword(s):

Inductively Coupled Plasma ◽

Buffer Capacity ◽

Metal Organic Framework ◽

Metal Organic Frameworks ◽

Analytical Techniques ◽

Aqueous Dispersions ◽

Inductively Coupled ◽

Plasma Mass Spectrometry ◽

Metal Organic

<div>UiO-66 is a zirconium-based metal-organic framework (MOF) that has numerous applications. Our group recently determined that UiO-66 is not as inert in aqueous dispersions as previously reported in the literature. The present work therefore assessed the behaviour of UiO-66 in buffers: 2-amino-2-(hydroxymethyl)-1,3-propanediol (TRIS), 4-(2-hydroxyethyl)piperazine-1-ethane sulfonic acid (HEPES), N-ethylmorpholine (NEM) and phosphate buffer (PB), all of which are commonly used in many UiO-66 applications. High pressure liquid chromatography and inductively coupled plasma mass spectrometry were used to monitor degradation of the MOF. In each buffer, the terephthalate linker was released to some extent, with a more pronounced leaching effect in the saline forms of these buffers. The HEPES buffer was found to be the most benign, whereas NEM and PB should be avoided at any concentration as they were shown to rapidly degrade the UiO-66 framework. Low concentration TRIS buffers are also recommended, although these offer minimal buffer capacity to adjust pH. Regardless of the buffer used, rapid terephthalate release was observed, indicating that the UiO-66 was attacked immediately after mixing with the buffer. In addition, the dissolution of zirconium, observed in some cases, intensified the UiO-66 decomposition process. These results demonstrate that sensitive analytical techniques have to be used to monitor the release of MOF components so as to quantify the stabilities of these materials in liquid environments.</div>

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