Modulating photophysical properties in a flexible porous host by regulating guest-assisted charge transfer interactions.

The 1D array of electron donor-acceptor chromophoric organic molecules is of paramount importance for photovoltaic, catalytic and optoelectronic applications. Herein, we report coordination driven 1D arrays of an electron-donor guest (fluorene, carbazole, dibenzofuran, and dibenzothiophene) and -phen chelator as an acceptor in a Zn-based porous coordination polymer, {[Zn(-phen)(ndc)]·DMF} (PCP-1). All the guest-encapsulated PCPs were characterized by performing single-crystal structure determinations and showed emission driven by charge transfer.

A triazole-based covalent organic framework as a photocatalyst toward visible-light-driven CO reduction to CH.

Solar-light driven reduction of CO to CH is a complex process involving multiple electron and proton transfer processes with various intermediates. Therefore, achieving high CH activity and selectivity remains a significant challenge. Covalent organic frameworks (COFs) represent an emerging class of photoactive semiconductors with molecular level structural tunability, modular band gaps, and high charge carrier generation and transport within the network.

Photocatalytic CO Reduction to Solar Fuels by a Chemically Stable Bimetallic Porphyrin-Based Framework.

Porphyrin-based photocatalysts have emerged as promising candidates for facilitating carbon dioxide (CO) reduction due to their exceptional light-harvesting properties. However, their performance is hindered by complex synthesis procedures, limited structural stability, inadequate CO activation capabilities, and a lack of comprehensive structure-property relationships. This study investigates the performance of a porphyrin-based bimetallic framework, [Cu(TPP)CuMoO] (TPP = tetrapyridylporphyrin), termed for photocatalytic CO reduction.

GFP Chromophore Integrated Conjugated Microporous Polymers toward Bioinspired Photocatalytic CO Reduction to CO.

The development of highly active, durable, and low-cost metal-free catalysts for the photocatalytic CO reduction reaction (CORR) is an efficient and environmentally friendly solution to address significant problems like global warming and high energy demand. In the present study, we have demonstrated the design and synthesis of a donor-acceptor based conjugated microporous polymer (CMP), TPA-GFP, by integrating an electron donor, tris(4-ethynylphenyl)amine (TPA), with a green fluorescent protein chromophore analogue ()-4-(2-hydroxy-3,5-diiodobenzylidene)-1-(4-iodophenyl)-2-methyl-1-imidazol-5(4)-one (o-HBDI-I3) (GFP). In comparison to nondonor 1,3,5-triethynylbenzene (TEB) based TEB-GFP CMP, photocatalytic CO reduction using donor-acceptor based TPA-GFP CMP displays a 3-fold increment of CO production yield with a maximum CO yield of 1666 μmol g at 12 h.

An adsorbate biased dynamic 3D porous framework for inverse CO sieving over CH.

Separating carbon dioxide (CO) from acetylene (CH) is one of the most critical and complex industrial separations due to similarities in physicochemical properties and molecular dimensions. Herein, we report a novel Ni-based three-dimensional framework {[Ni(μ-OH)(μ-OH)(1,4-ndc)](3HO)} (1,4-ndc = 1,4-naphthalenedicarboxylate) with a one-dimensional pore channel (3.05 × 3.

Microwave Assisted Fast Synthesis of a Donor-Acceptor COF Towards Photooxidative Amidation Catalysis.

The synthesis of covalent organic frameworks (COFs) at bulk scale require robust, straightforward, and cost-effective techniques. However, the traditional solvothermal synthetic methods of COFs suffer low scalability as well as requirement of sensitive reaction environment and multiday reaction time (2-10 days) which greatly restricts their practical application. Here, we report microwave assisted rapid and optimized synthesis of a donor-acceptor (D-A) based highly crystalline COF, TzPm-COF in second (10 sec) to minute (10 min) time scale.

COF-Topological Quantum Material Nano-heterostructure for CO to Syngas Production under Visible Light.

Efficient solar-driven syngas production (CO+H mixture) from CO and HO with a suitable photocatalyst and fundamental understanding of the reaction mechanism are the desired approach towards the carbon recycling process. Herein, we report the design and development of an unique COF-topological quantum material nano-heterostructure, COF@TI with a newly synthesized donor-acceptor based COF and two dimensional (2D) nanosheets of strong topological insulator (TI), PbBiTe. The intrinsic robust metallic surfaces of the TI act as electron reservoir, minimising the fast electron-hole recombination process, and the presence of 6s lone pairs in Pb and Bi in the TI helps for efficient CO binding, which are responsible for boosting overall catalytic activity.

Pore-Confined π-Chromophoric Tetracene as a Visible Light Harvester toward MOF-Based Photocatalytic CO Reduction in Water.

Integrating photoactive π-chromophoric guest molecules inside the MOF nanopore can result in the emergence of light-responsive features, which in turn can be utilized for developing photoactive materials with inherent properties of MOF. Herein, we report the confining of π-chromophoric tetracene () molecules inside the nanospace of postmodified Zr-MOF-808 () with MBA molecules (MBA = 2-(5'-methyl-[2,2'-bipyridine]-5-yl)acetic acid) for effectively utilizing its light-harvesting properties toward photocatalytic CO reduction. The confinement of the molecules as a photosensitizer and the covalent grafting of a catalytically active [Re(MBA)(CO)Cl] complex, postsynthetically, result in a single integrated catalytic system named .

Confining charge-transfer complex in a metal-organic framework for photocatalytic CO reduction in water.

In the quest for renewable fuel production, the selective conversion of CO to CH under visible light in water is a leading-edge challenge considering the involvement of kinetically sluggish multiple elementary steps. Herein, 1-pyrenebutyric acid is post-synthetically grafted in a defect-engineered Zr-based metal organic framework by replacing exchangeable formate. Then, methyl viologen is incorporated in the confined space of post-modified MOF to achieve donor-acceptor complex, which acts as an antenna to harvest visible light, and regulates electron transfer to the catalytic center (Zr-oxo cluster) to enable visible-light-driven CO reduction reaction.

Confining Molecular Photosensitizer and Catalyst in MOF toward Artificial Photosynthesis: Validating Electron Transfer by DRIFT Study.

Exploration of different chemical systems for photocatalytic CO reduction by using sunlight en route to the achievement of artificial photosynthesis stems from global warming and the energy crisis. In this work, we have covalently grafted the molecular photosensitizer (PS) [Ru(MBA)(bpy)]Cl (bpy: 2,2'-bipyridine) and the catalyst [Mn(MBA)(CO)Br] inside the Zr-MOF-808 () nanopore postmodified with 2-(5'-methyl-[2,2'-bipyridine]-5-yl)acetic acid (H-MBA) and developed a single integrated system named for the CO reduction reaction (CORR). is found to be active toward CO-to-CO conversion, with a maximum production of 1027 μmol g after 26 h of reaction having >99% selectivity in the aqueous medium without any additional hole scavenger.

Complexing Eu/Tb in a Nanoscale Postmodified Zr-MOF toward Temperature-Modulated Multispectrum Chromism.

In recent years, extensive research has been directed toward the successful preparation of nanoscale luminescent thermometers with high sensitivities operative in a broad temperature range. To achieve this goal, we have devised a unique design and facile multistep synthesis of compounds by confining Ln-complexes (Ln = Eu/Tb) into a robust nanoscale (MOF-808) via postsynthetic modification. Covalent grafting of 4-(4'-carboxyphenyl)-2,2':6,2″terpyridine ligand (ctpy) with a high triplet state energy and corresponding immobilization of bimetallic Ln ions resulted in yellow light-emitting to achieve a sensitivity of 5.

Confinement Matters: Stabilization of CdS Nanoparticles inside a Postmodified MOF toward Photocatalytic Hydrogen Evolution.

Insights into developing innovative routes for the stabilization of photogenerated charge-separated states by suppressing charge recombination in photocatalysts is a topic of immense importance. Herein, we report the synthesis of a metal-organic framework (MOF)-based composite where CdS nanoparticles (NPs) are confined inside the nanosized pores of Zr-based MOF-808, namely, CdS@MOF-808. Anchoring l-cysteine into the nanospace of MOF-808 via postsynthetic ligand exchange allows the capture of Cd ions from their aqueous solution, which are further utilized for in situ growth of CdS NPs inside the nanosized MOF pores.

Visible-Light-Driven Photocatalytic CO Reduction to CO/CH Using a Metal-Organic "Soft" Coordination Polymer Gel.

The self-assembly of a well-defined and astutely designed, low-molecular weight gelator (LMWG) based linker with a suitable metal ion is a promising method for preparing photocatalytically active coordination polymer gels. Here, we report the design, synthesis, and gelation behaviour of a tetrapodal LMWG based on a porphyrin core connected to four terpyridine units (TPY-POR) through amide linkages. The self-assembly of TPY-POR LMWG with Ru ions results in a Ru-TPY-POR coordination polymer gel (CPG), with a nanoscroll morphology.

Charge-transfer regulated visible light driven photocatalytic H production and CO reduction in tetrathiafulvalene based coordination polymer gel.

The much-needed renewable alternatives to fossil fuel can be achieved efficiently and sustainably by converting solar energy to fuels via hydrogen generation from water or CO reduction. Herein, a soft processable metal-organic hybrid material is developed and studied for photocatalytic activity towards H production and CO reduction to CO and CH under visible light as well as direct sunlight irradiation. A tetrapodal low molecular weight gelator (LMWG) is synthesized by integrating tetrathiafulvalene (TTF) and terpyridine (TPY) derivatives through amide linkages and results in TPY-TTF LMWG.

Multicolour lanthanide(III) porous 1D coordination polymers: tunable wide spectrum emission and efficient Cu sensing.

Five isostructural 1D porous coordination polymers (PCPs) with a general formula of {[M(L)(DMF)(HO)]·1.5HO} [M = Tb (1), Eu (2), Yb (3), Nd (4) and Er (5)] have been synthesized using a flexible tripodal organic linker (L) and characterized. Tb (1) and Eu (2) PCPs exhibit metal-based green and red emission, respectively, whereas Yb (3), Nd (4) and Er (5) PCPs show near-infrared (NIR) emission.

Metal-Free Catalysis: A Redox-Active Donor-Acceptor Conjugated Microporous Polymer for Selective Visible-Light-Driven CO Reduction to CH.

Achieving more than a two-electron photochemical CO reduction process using a metal-free system is quite exciting and challenging, as it needs proper channeling of electrons. In the present study, we report the rational design and synthesis of a redox-active conjugated microporous polymer (CMP), TPA-PQ, by assimilating an electron donor, tris(4-ethynylphenyl)amine (TPA), with an acceptor, phenanthraquinone (PQ). The TPA-PQ shows intramolecular charge-transfer (ICT)-assisted catalytic activity for visible-light-driven photoreduction of CO to CH (yield = 32.