Ten-Million-Fold Increase in the Electrical Conductivity of a MOF by Doping of Iodine Into MOF Integrated Mixed Matrix Membrane.

The development of electrically conductive membranes is essential for advancing future technologies like electronic devices, supercapacitors, and batteries. Newly synthesized doubly interpenetrated 3D-Cd-MOF (Metal-Organic-Framework) containing angular tetra-carboxylate is found to display very poor electrical conductivity (10 S cm). However, it exhibits an exceptional ability to adsorb I (I@Cd-MOF) which shows increased electrical conductivity of the order of 10 S cm.

Light-Induced Antiferromagnetic to Ferromagnetic Transition in Halogen Substituted 1,4-Bis(imidazolyl)benzene Systems: An Effect of Spin-Orbit Coupling and π-Stacking in Enhanced Photomagnetism.

Employing the spin-orbit coupling effect by introducing halogen substituents is an excellent strategy to tune the magnetic behavior of organic or metal-organic materials. Light is an alternative tool to modulate the magnetic behavior of a material through a photoinduced electron transfer process, without changing its chemical identity. In this work, three halogen containing 1,4-bis(4,5-diphenyl-1-imidazol-2-yl)benzene (F-BDPI, Cl-BDPI and Br-BDPI) systems have been chosen to exploit the role of halogen substituents on solid-state photoinduced phenomena.

Superprotonic Conductivity by Synergistic Blending of Coordination Polymers with Organic Polymers: Fabrication of Durable and Flexible Proton Exchange Membranes.

Creation of an efficient and cost-effective proton exchange membrane (PEM) has emerged as a propitious solution to address the challenges of renewable energy development. Coordination polymers (CPs) have garnered significant interest due to their multifunctional applications and moldability, along with long-range order. To leverage the potential of CPs in fuel cells, it is essential to integrate microcrystalline CPs into organic polymers to prepare membranes and avoid grain boundary issues.

Proton Conducting Metal-Organic Frameworks (MOFs) via Post Synthetic Transmetallation and Water Induced Structural Transformations.

Post Synthetic Modification (PSM) of Metal-Organic Frameworks (MOFs) is a crucial strategy for developing new MOFs with enhanced functional properties compared to their parent one. PSM can be accomplished through various methods:1) modification of organic linkers; 2) exchange of metal ions or nodes; and 3) inclusion or exchange of solvent/guest molecules. Herein, PSM of bimetallic and monometallic MOFs containing biphenyl dinitro-tetra-carboxylates (NCA) are demonstrated.

Amine Functionalization of Channels of Metal-Organic Frameworks for Effective Chemical Fixation of Carbon Dioxide: A Comparative Study with Three Newly Designed Porous Networks.

Catalytic transformation of CO into value-added chemical products can provide an appropriate solution for the raising environmental issues. To date, various metal-organic frameworks (MOFs) with transition metal ions have been explored for CO capture and conversion, but alkaline earth metal-based MOFs are comparatively less studied. Metal ions like Sr(II) having relatively large radius give rise to a high coordination number resulting in higher stability of the MOFs.

Bimetallic Organic Frameworks via In Situ Solvothermal Sol-Gel-Crystal and Sol-Crystal Transformation as Durable Electrocatalysts for Oxygen Reduction Reaction.

The solvothermal conversion of metal-organic gels (MOGs) to crystalline metal-organic frameworks (MOFs) represents a versatile and ingenious strategy that has been employed for the synthesis of MOF materials with specific morphologies, high yield, and improved functional properties. Herein, we have adopted an solvothermal conversion of bimetallic MOGs to crystalline bimetallic MOFs with the aim of introducing a redox-active metal heterogeneity into the monometallic counterpart. The formation of bimetallic and solvothermal sol-gel-crystal and sol-crystal transformation is found to depend on the solvent systems used.

Differentiating aliphatic and aromatic alcohols using triazine-based supramolecular organogelators: end group-specific selective gelation with chain length of alcohols.

Supramolecular gels have an extensive range of potential applications, out of which stimuli-responsive materials are a topic of contemporary research. Gels being kinetically entrapped materials can be tuned to different forms using external chemical stimuli. In this context, three different triazine gelators, each containing a unique end group, were examined for gelation in various solvent systems.

Photo-responsive metal-organic gels of rigid phenylene-1,3-di-substituted angular dienes with metal halides: gel-to-gel transformations triggered by [2 + 2] polymerization.

Herein, the first report on gel-to-gel transformations [2 + 2] photopolymerization in MOGs of metal halides and rigid dienes is presented. The MOGs and their xerogels show exceptional ability to undergo [2 + 2] polymerisation upon UV irradiation. Gel-to-gel transformations are very rare as the post-modification of gelators weakens the gel and transforms it to a sol.

conversion of a MOG to a crystalline MOF: a case study on solvent-dependent gelation and crystallization.

Herein, we report transformation of a metal-organic gel (MOG) to a crystalline metal-organic framework (MOF) and solvent-dependent gelation/crystallization solvothermal reactions of a tetracarboxylic acid, namely 4,4'-dinitro-2,2',6,6'-tetracarboxybiphenyl, and ZnSO. The results provide structural insights into MOGs at the molecular level and also help in the synthesis of crystalline MOFs that are otherwise difficult to obtain.

Grown Mn(II) MOF upon Nickel Foam Acts as a Robust Self-Supporting Bifunctional Electrode for Overall Water Splitting: A Bimetallic Synergistic Collaboration Strategy.

The design of highly efficient, cost-effective non-noble metal-based electrocatalysts with superior stability for overall water splitting (OWS) reactions is of great importance as well as of immense challenge for the upcoming sustainable and green energy conversion technologies. Herein, a convenient and simple solvothermal method has been adopted to fabricate a self-supported, binder-free 3D electrode () by the direct growth of a newly synthesized carboxylate-based pristine Mn(II)-metal-organic framework () upon the conducting substrate nickel foam (NF). The binder-free electrode exhibits excellent performances toward OWS with ultralow overpotentials of 280 mV@20 mA cm for the oxygen evolution reaction (OER) and 125 mV@10 mA cm for the hydrogen evolution reaction (HER) with remarkable durability.

Halogen⋅⋅⋅Halogen and Halogen⋅⋅⋅π Interactions Enabled Reversible Photo-oligomerization of Conjugated Dienones: Visible Light Triggered Single-Crystal-to-Single-Crystal Transformation.

The synthesis of reversible oligomer/polymers is fascinating both from the perspective of the fundamental understanding as well as their applications, ranging from biomedical to self-healing smart materials. On the other hand, the reactions that occur in single-crystal-to-single-crystal (SCSC) fashion offer great details of the structure, geometry and stereochemistry of the product. However, SCSC [2+2] oligomerization is rather difficult and rare.

Comparative Study of Nitro- and Azide-Functionalized Zn -Based Coordination Polymers (CPs) as Fluorescent Turn-On Probes for Rapid and Selective Detection of H S in Living Cells.

Selective detection of H S in the cellular systems using fluorescent CPs/MOFs is of great scientific interest due to their outstanding aqueous stability, biocompatibility and real-time detection ability. Fabrication of such materials using complete biologically essential elements and applying them as an efficient biosensor is still quite challenging. In this context, two newly synthesized CPs containing biologically essential metal ion (Zn) and nitro/azido functional groups into the framework to sense extracellular and intracellular H S by reducing into respective amines are presented.

Metal-organic frameworks as proton conductors: strategies for improved proton conductivity.

Recent studies on proton conductivity using pristine MOFs and their composite materials have established an outstanding area of research owing to their potential applications for the development of high performance solid state proton conductors (SSPCs) and proton exchange membranes (PEMs) in fuel cells (FCs). MOFs, as crystalline organic and inorganic hybrid materials, provide a large number of degrees of freedom in their framework composition, coordination environment, and chemically functionalized pores for the targeted design of improved proton carriers, functioning over a wide range of temperature and humidity conditions. Herein, our efforts have been emphasized on fundamental principles and different design strategies to achieve enhanced proton conductivity with appropriate examples.

Porous Li-MOF as a solid-state electrolyte: exploration of lithium ion conductivity through bio-inspired ionic channels.

A rarely porous Li-MOF (Li-AOIA) with surface area of 605 m2 g-1 was employed for the formation of an emerging class of solid-state lithium ion electrolytes. Infiltration of LiBF4 into Li-AOIA afforded Li-AOIA@BF4 with ionic conductivity of 1.09 × 10-5 S cm-1 at room temperature and an activation energy of 0.

Photochemical [2 + 2] polymerization of metal-organic gels of a rigid and angular diene with silver-salts of diverse anions: selective dye-sorption and luminescence by xerogels.

Two similar types of dienes, one rigid and the other flexible, were explored for their gel formation abilities with Ag(i) salts. The rigid and angular dienes have shown an exceptional ability for gel formation with silver salts of nitrate, triflate, tetrafluoro borate and hexafluorophosphate. These metal-organic gels (MOGs) and their xerogels are found to have an excellent ability to undergo the photochemical [2 + 2] polymerization reaction upon irradiation.

Coordination polymers as heterogeneous catalysts in hydrogen evolution and oxygen evolution reactions.

The efficiency of hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in the process of electrochemical water oxidation will determine the competence for mass distributions of sustainable energy conversion technologies in the future. Recently, coordination polymers (CPs)/metal-organic frameworks (MOFs) have emerged as desirable hybrid materials for catalysing electrochemical energy conversion processes due to their unique advantages, such as crystalline porous structure, high surface area, and diverse and tunable chemical components. This feature article briefly summarizes the recent part of the fast growing literature on electrocatalysis by pristine MOF/CPs, MOF composites, as well as post-synthetically modified materials for HER, OER and overall water splitting reactions.

2D MOFs with Ni(II), Cu(II), and Co(II) as Efficient Oxygen Evolution Electrocatalysts: Rationalization of Catalytic Performance Structure of the MOFs and Potential of the Redox Couples.

Earth-abundant transition-metal-based metal-organic frameworks (MOFs) are of immense interest for the development of efficient and durable heterogeneous water splitting electrocatalysts. This repot explores the design of two-dimensional (2D) MOFs with redox-active metal centers (Ni(II), Co(II), and Cu(II)) containing two types of electron-rich linkers such as bis(5-azabenzimidazole), linear and angular , and aromatic dicarboxylates. The electron-rich linkers are considered to stabilize the higher oxidation state of the redox-active metal centers in the course of the electrocatalytic oxygen evolution reaction (OER) process.

Is the origin of green fluorescence in unsymmetrical four-ring bent-core liquid crystals single or double proton transfer?

The origin of green fluorescence in unsymmetrical four-ring bent-core liquid crystals (BCLCs) is not understood clearly. There is no analysis of the photo-physical properties, in particular, the excited state dynamical behaviour, of these molecules. Because of the availability of two proton transfer sites in these systems, there is no clear explanation of the involvement of single or double proton transfer reactions in the origin of the large Stokes shifted green fluorescence band.

Solid or gel? Which one works better for [2 + 2] photochemical polymerization in pyridine appended flexible phenylene 1, 4-bis-olefins by Ag(i) templation?

Two diene molecules were shown to undergo photopolymerization reactions in their metal-organic gels and xerogels, while their respective crystalline CPs are photostable. These reactions reveal the advantages of the gels and xerogels compared to their crystalline counterparts and also the utility of AgAg interactions in the gels to promote topochemical polymerizations.

Proton-Conducting Hydrogen-Bonded 3D Frameworks of Imidazo-Pyridine-Based Coordination Complexes Containing Naphthalene Disulfonates in Rhomboid Channels.

Coordination complexes of an olefinic molecule (PIP) containing pyridine and imidazopyridine moieties with Zn /Ni metal salts were shown to exhibit appreciable proton conductivity. These complexes form 3D-hydrogen bonded frameworks containing rhomboidal channels that are occupied by uncoordinated 1,5-naphthalenedisulfonate (NDS). The extensive hydrogen bonding between the frameworks and NDS resulted in thermally stable and water-insoluble materials.

Photoinduced Bending of Single Crystals of a Linear Bis-Olefin via Water-Templated Solid-State [2+2] Photopolymerization Reaction.

The single crystals of two structural isomers of bis-olefinic molecules were shown to have contrasting properties in terms of their photoreactivity: one exhibits an excellent ability to form polymers, accompanied with bending of crystals upon irradiation, while the other is photostable. The photoreactive crystal is a first example in which [2+2] polymerization leads to bending of the crystals, with implications for the design of photoactuators. The hydrate formation ability of one of these molecular isomers promotes the solid-state reactivity in its crystal, as the H O molecules act as a template to bring the olefin molecules into the required arrangement for [2+2] polymerization.

Tailoring Coordination Polymers by Substituent Effect: A Bifunctional Co -Doped 1D-Coordination Network with Electrochemical Water Oxidation and Nitroaromatics Sensing.

Three Cd coordination polymers (CPs) were synthesized with a tripodal ligand N,N',N' '-tris(4-pyridinylmethyl)-1,3,5-benzenetricarboxamide in combination with three different substituted isophthalic acids with general formulas {[Cd (L)(NIP) (H O) ].4H O} , (CP-1), {[Cd (L)(AIP) (H O) ].4H O} , (CP-2) and {[Cd(L)(BIP) (H O)].

Isoreticular Expansion of Metal-Organic Frameworks via Pillaring of Metal Templated Tunable Building Layers: Hydrogen Storage and Selective CO Capture.

The deliberate construction of isoreticular eea-metal-organic frameworks (MOFs) (Cu-eea-1, Cu-eea-2 and Cu-eea-3) and rtl-MOFs (Co-rtl-1 and Co-rtl-2) has been accomplished based on the ligand-to-axial pillaring of supermolecular building layers. The use of different metal ions resulted in two types of supermolecular building layers (SBLs): Kagome (kgm) and square lattices (sql) which further interconnect to form anticipated 3D-MOFs. The isoreticular expansion of (3,6)-connected Cu-MOFs has been achieved with desired eea-topology based on kgm building layers.

Isostructural Ni Metal-Organic Frameworks (MOFs) for Efficient Electrocatalysis of Oxygen Evolution Reaction and for Gas Sorption Properties.

Design and synthesis of stable, active and cost-effective electrocatalyst for water splitting applications is an emerging area of research, given the depletion of fossil fuels. Herein, two isostructural Ni redox-active metal-organic frameworks (MOFs) containing flexible tripodal trispyridyl ligand (L) and linear dicarboxylates such as terephthalate (TA) and 2-aminoterphthalate (H NTA) are studied for their catalytic activity in oxygen evaluation reaction (OER). The 2D-layered MOFs form 3D hydrogen bonded frameworks containing one-dimensional hydrophilic channels that are filled with water molecules.

MOF-templated cobalt nanoparticles embedded in nitrogen-doped porous carbon: a bifunctional electrocatalyst for overall water splitting.

Development of cost-effective and efficient non noble metal electrocatalysts has immense importance towards sustainable energy technologies. Herein, a newly constructed porous Co(ii)-metal organic framework (MOF) has been utilized for the synthesis of cobalt nanoparticles embedded in N-doped porous carbon, (Co@NPC), a facile MOF-annealing strategy, at an optimum temperature of 800 °C under an argon atmosphere. DMF molecules present in the form of solvated guests and cations within the 3D-framework serve as a source for N-doping during the formation of the porous graphitic carbon upon carbonization.