scholarly journals Femto- to Millisecond Time-Resolved Photodynamics of a Double-Functionalized Push–Pull Organic Linker: Potential Candidate for Optoelectronically Active MOFs

2020 ◽  
Vol 21 (12) ◽  
pp. 4366
Author(s):  
Mario Gutiérrez ◽  
Lucie Duplouy-Armani ◽  
Lorenzo Angiolini ◽  
Mercedes Pintado-Sierra ◽  
Félix Sánchez ◽  
...  

The design of improved organic linkers for the further engineering of smarter metal–organic framework (MOF) materials has become a paramount task for a wide number of material scientists. In this report, a luminescent double-functionalized push–pull (electron donor–acceptor) archetype organic molecule, dimethyl 4-amino-8-cyanonaphthalene-2,6-dicarboxylate (Me2CANADC), has been synthesized and characterized. The optical steady-state properties of Me2CANADC are strongly influenced by the surrounding environment as a direct consequence of its strong charge transfer (CT) character. The relaxation from its first electronically excited singlet state follows a double pathway: (1) on one side deactivating from its local excited (LE) state in the sub-picosecond or picosecond time domain, and (2) on the other side undergoing an ultrafast intramolecular charge transfer (ICT) reaction that is slowing down in viscous solvents. The deactivation to the ground state of these species with CT character is the origin of the Me2CANADC luminescence, and they present solvent-dependent lifetime values ranging from 8 to 18 ns. The slow photodynamics of Me2CANADC unveils the coexistence of a non-emissive triplet excited state and the formation of a long-lived charge separated state (2 µs). These observations highlight the promising optical properties of Me2CANADC linker, opening a window for the design of new functional MOFs with huge potential to be applied in the fields of luminescent sensing and optoelectronics.

2018 ◽  
Vol 20 (40) ◽  
pp. 25772-25779 ◽  
Author(s):  
Pavel M. Usov ◽  
Chanel F. Leong ◽  
Bun Chan ◽  
Mikihiro Hayashi ◽  
Hiroshi Kitagawa ◽  
...  

Donor–Acceptor Metal–Organic Frameworks display redox and pressure dependent charge transfer properties.


2018 ◽  
Vol 9 (13) ◽  
pp. 3282-3289 ◽  
Author(s):  
S. Yamamoto ◽  
J. Pirillo ◽  
Y. Hijikata ◽  
Z. Zhang ◽  
K. Awaga

Using the “crystal sponge” approach, weak organic electron donor molecules were impregnated and evenly distributed in a crystal of a metal–organic framework (MOF), with the self-assembly of the donor–acceptor pairs with electron acceptor ligands. The nanopores of the MOF confined them and induced a charge transfer phenomenon, which would not occur between donor and acceptor molecules in a bulk scale.


2014 ◽  
Vol 5 (12) ◽  
pp. 4724-4728 ◽  
Author(s):  
C. F. Leong ◽  
B. Chan ◽  
T. B. Faust ◽  
D. M. D'Alessandro

Donor–acceptor charge transfer interactions in a tetrathiafulvalene–naphthalene diimide-based metal–organic framework (MOF) are interrogated using a complementary suite of solid state spectroscopic, electrochemical and spectroelectrochemical methods along with computational calculations.


2014 ◽  
Vol 2 (10) ◽  
pp. 3389-3398 ◽  
Author(s):  
Kirsty Leong ◽  
Michael E. Foster ◽  
Bryan M. Wong ◽  
Erik D. Spoerke ◽  
Dara Van Gough ◽  
...  

A metal–organic framework serves as a multifunctional host for donor and acceptor molecules, enabling energy harvesting and transfer without phase segregation.


2020 ◽  
Vol 124 (39) ◽  
pp. 21635-21640
Author(s):  
Ting-Hsun Yang ◽  
Shao-Heng Yang ◽  
Yu-Chuan Chen ◽  
Darwin Kurniawan ◽  
Wei-Hung Chiang ◽  
...  

2017 ◽  
Vol 56 (6) ◽  
pp. 060307 ◽  
Author(s):  
Kouji Taniguchi ◽  
Keisuke Narushima ◽  
Kayo Yamagishi ◽  
Nanami Shito ◽  
Wataru Kosaka ◽  
...  

Author(s):  
Lin Ren ◽  
Xudong Zhao ◽  
Baosheng Liu ◽  
Hongliang Huang

Abstract Rapid removal of radioactive strontium from nuclear wastewater is of great significance for environment safety and human health. This work reported the effective adsorption of strontium ion in a stable dual-group metal-organic framework, Zr6(OH)14(BDC-(COOH)2)4(SO4)0.75 (Zr-BDC-COOH-SO4), which contains strontium-chelating groups (-COOH and SO4) and strongly ionizable group (-COOH). Zr-BDC-COOH-SO4 exhibits very rapid adsorption kinetics (<5 min) and a maximum adsorption capacity of 67.5 mg g−1. The adsorption behaviors can be well evaluated by pseudo-second-order model and Langmuir isotherm model. Further investigations indicate that the adsorption of Sr2+ in Zr-BDC-COOH-SO4 would not be interfered by solution pH and adsorption temperature obviously. Feasible regeneration of the adsorbent was also demonstrated through a simple elution method. Mechanism investigation suggests that free -COOH contributes to the rapid adsorption based on electrostatic interaction while introduction of -SO4 can enhance the adsorption capacity largely. Thus, these results suggest that Zr-BDC-COOH-SO4 might be a potential candidate for Sr2+ removal and introducing dual groups is an effective strategy for designing high-efficiency adsorbents.


2019 ◽  
Author(s):  
Barbara Souza ◽  
Lorenzo Dona ◽  
Kirill Titov ◽  
Paolo Bruzzese ◽  
Zhixin Zeng ◽  
...  

Nanocomposites comprising metal-organic frameworks (MOFs) embedded in a polymeric matrix are promising carriers for drug delivery applications. While understanding the chemical and physical transformations of MOFs during the release of confined drug molecules is challenging, this is central to devising better ways for controlled release of therapeutic agents. Herein we demonstrate the efficacy of synchrotron microspectroscopy to track the in situ release of 5-fluorouracil (5-FU) anticancer drug molecules from a drug@MOF/polymer composite (5-FU@HKUST-1/polyurethane). Using experimental time-resolved infrared spectra jointly with newly developed density functional theory calculations, we reveal the detailed dynamics of vibrational motions underpinning the dissociation of 5-FU bound to the framework of HKUST-1 upon water exposure. We discover that HKUST-1 creates hydrophilic channels within the hydrophobic polyurethane matrix hence helping to tune drug release rate. The synergy between a hydrophilic MOF with a hydrophobic polymer can be harnessed to engineer a tunable nanocomposite that alleviates the unwanted burst effect commonly encountered in drug delivery.<br>


2020 ◽  
Author(s):  
Bikash Garai ◽  
Volodymyr Bon ◽  
Francesco Walenszus ◽  
Azat Khadiev ◽  
Dmitri Novikov ◽  
...  

Variation in the metal centres of M-M paddle-wheel SBU results in the formation of isostructural DUT-49(M) frameworks. However, the porosity of the framework was found to be different for each of the structures. While a high and moderate porosity was obtained for DUT-49(Cu) and DUT-49(Ni), respectively, other members of the series [DUT-49(M); M= Mn, Fe, Co, Zn, Cd] show very low porosity and shapes of the adsorption isotherms which is not expected for op phases of these MOFs. Investigation on those MOFs revealed that those frameworks undergo structural collapse during the solvent removal at the activation step. Thus, herein, we aimed to study the detailed structural transformations that are possibly occurring during the removal of the subcritical fluid from the framework.


Sign in / Sign up

Export Citation Format

Share Document