Metalloporphyrinic metal-organic frameworks: Controlled synthesis for catalytic applications in environmental and biological media

Synthesis of silver nanoparticles embedded into melamine polyaminal networks as antibacterial and anticancer active agents

Silver nanoparticles were successfully incorporated into a melamine-based polymer, resulting in the synthesis of (Ag NPs@Bipy-PAN) through a reverse double solvent approach. The synthesised Ag NPs@Bipy-PAN polymer underwent extensive characterisation through Powder X-ray Diffraction (PXRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy and Energy Dispersive X-ray (EDX) and Thermal Gravimetric Analysis. PXRD analysis confirmed the successful encapsulation of Ag nanoparticles and provided insights into the amorphous nature of the polymer following encapsulation. SEM and EDX analyses further corroborated the presence and distribution of Ag nanoparticles on the polymer surface. The biological efficacy of the Ag NPs@Bipy-PAN polymer was evaluated through antibacterial, anti-breast cancer, and biocompatibility assays. The results demonstrated notable antibacterial and anticancer activities, with significant efficacy against bacterial strains and breast cancer cells. Biocompatibility assessments indicated acceptable compatibility, particularly at a concentration of 2.5 mg/mL, compared to untreated control cells. These findings suggest that Ag NPs@Bipy-PAN has considerable potential as a candidate for cancer-targeted and antimicrobial drug delivery systems. The incorporation of silver nanoparticles into the melamine-based polymer enhances the safety profile of these systems in in vivo conditions, making them a viable option for advanced therapeutic applications.

A review of biocompatible polymer-functionalized two-dimensional materials: Emerging contenders for biosensors and bioelectronics applications

Bioelectronics, a field pivotal in monitoring and stimulating biological processes, demands innovative nanomaterials as detection platforms. Two-dimensional (2D) materials, with their thin structures and exceptional physicochemical properties, have emerged as critical substances in this research. However, these materials face challenges in biomedical applications due to issues related to their biological compatibility, adaptability, functionality, and nano-bio surface characteristics. This review examines surface modifications using covalent and non-covalent-based polymer-functionalization strategies to overcome these limitations by enhancing the biological compatibility, adaptability, and functionality of 2D nanomaterials. These surface modifications aim to create stable and long-lasting therapeutic effects, significantly paving the way for the practical application of polymer-functionalized 2D materials in biosensors and bioelectronics. The review paper critically summarizes the surface functionalization of 2D nanomaterials with biocompatible polymers, including g-C3N4, graphene family, MXene, BP, MOF, and TMDCs, highlighting their current state, physicochemical structures, synthesis methods, material characteristics, and applications in biosensors and bioelectronics. The paper concludes with a discussion of prospects, challenges, and numerous opportunities in the evolving field of bioelectronics.

Enzyme-loaded manganese-porphyrin metal-organic nanoframeworks for oxygen-evolving photodynamic therapy of hypoxic cells

Photodynamic therapy (PDT) is attracting great attention for cancer treatments, while its therapeutic efficacy is limited by unsatisfactory photosensitizers and hypoxic tumor microenvironment (TME). To address these problems, we have developed catalase-loaded manganese-porphyrin frameworks (CAT@MnPFs) for catalytically-assisted PDT of cancer cells. CAT@MnPFs were constructed by the assembly of Mn2+ ions and PpIX into MnPFs and the subsequent loading of catalase. Under 650 nm light irradiation, the porphyrin (Protoporphyrin IX) within the structure of CAT@MnPFs can convert oxygen (O2) into singlet oxygen (1O2), showing the photodynamic effect. Importantly, the loaded catalase can decompose hydrogen peroxide (H2O2) into O2 with a huge elevation of O2 level (13.22 mg L-1) in 600 s, thus promoting 1O2 generation via PDT. As a result, CAT@MnPFs combined with 650 nm light can effectively ablate cancer cells due to the catalase-assisted oxygen-evolving PDT, showing a high therapeutic efficacy. Meanwhile, after the incubation with CAT@MnPFs, unobvious damage can be found in normal and red blood cells. Thus, the obtained CAT@MnPFs integrate the advantage of photosensitizers and catalase for oxygen-evolving PDT, which can provide some insight for treating hypoxic cells.

Porphyrin-based covalent organic frameworks from design, synthesis to biological applications

Covalent organic frameworks (COFs) constitute a class of highly functional porous materials composed of lightweight elements interconnected by covalent bonds, characterized by structural order, high crystallinity, and large specific surface area. The integration of naturally occurring porphyrin molecules, renowned for their inherent rigidity and conjugate planarity, as building blocks in COFs has garnered significant attention. This strategic incorporation addresses the limitations associated with free-standing porphyrins, resulting in the creation of well-organized porous crystal structures with molecular-level directional arrangements. The unique optical, electrical, and biochemical properties inherent to porphyrin molecules endow these COFs with diversified applications, particularly in the realm of biology. This review comprehensively explores the synthesis and modulation strategies employed in the development of porphyrin-based COFs and delves into their multifaceted applications in biological contexts. A chronological depiction of the evolution from design to application is presented, accompanied by an analysis of the existing challenges. Furthermore, this review offers directional guidance for the structural design of porphyrin-based COFs and underscores their promising prospects in the field of biology.

Porphyrin Metal-organic Framework Sensors for Chemical and Biological Sensing

Porphyrins and porphyrin derivatives have been intensively explored for a number of applications such as sensing, catalysis, adsorption, and photocatalysis due to their outstanding photophysical properties. Their usage in sensing applications, however, is limited by intrinsic defects such as physiological instability and self-quenching. To reduce self-quenching susceptibility, researchers have developed porphyrin metal-organic frameworks (MOFs). Metal-organic frameworks (MOFs), a unique type of hybrid porous coordination polymers comprised of metal ions linked by organic linkers, are gaining popularity. Porphyrin molecules can be integrated into MOFs or employed as organic linkers in the production of MOFs. Porphyrin-based MOFs are a separate branch of the huge MOF family that combines the distinguishing qualities of porphyrins (e.g., fluorescent nature) and MOFs (e.g., high surface area, high porosity) to enable sensing applications with higher sensitivity, specificity, and extended target range. The key synthesis techniques for porphyrin-based MOFs, such as porphyrin@MOFs, porphyrinic MOFs, and composite porphyrinic MOFs, are outlined in this review article. This review article focuses on current advances and breakthroughs in the field of porphyrin-based MOFs for detecting a variety of targets (for example, metal ions, anions, explosives, biomolecules, pH, and toxins). Finally, the issues and potential future uses of this class of emerging materials for sensing applications are reviewed.

Recent Developments in Porphyrin-Based Metal-Organic Framework Materials for Water Remediation under Visible-Light Irradiation

Access to clean drinking water is a basic requirement, and eliminating pollutants from wastewater is important for saving water ecosystems. The porous structure and surface characteristics of metal-organic frameworks (MOFs) can function as a perfect scaffold for removing toxic compounds from wastewater. Porphyrins are promising building blocks for constructing MOFs. Porphyrin-based metal-organic frameworks (P-MOFs) have been fabricated using porphyrin ligands, metal clusters, or ions. These materials can harvest light from a wide region of the solar spectrum, and their framework morphology and physicochemical properties can be controlled by changing their peripheral subunits or metal ions. These porous crystalline materials have generated interest because of their distinctive characteristics, including large permanent porosity, interesting surface morphology, broad conformational diversity, high photostability, and semiconducting nature. This article discusses the recent progress and usefulness of P-MOFs. The fabrication procedures of P-MOFs are discussed, followed by the adsorptive and photocatalytic removal of contaminants from wastewater. The relationships between the geometries of P-MOFs and their light-harvesting and charge-transfer mechanisms for the photocatalytic degradation of pollutants are highlighted. Finally, some future perspectives and obstacles in the photodegradation usage of P-MOFs are discussed, along with feasible research directions to standardize efficient photocatalysts for improved photodegradation for water treatment.

P3MOT-decorated metal-porphyrin-based zirconium-MOF for the efficient electrochemical detection of 4-nitrobenzaldehyde

A novel hybrid composite integrating conductive poly-3-methoxythiophene and PCN-222(Fe) (porphyrin-metal-organic frameworks) was synthesized using an in situ polymerization strategy. Leveraging the large specific area of MOFs and the low electrical resistance of conductive polymers, the modified electrode proved to be a promising candidate for the electrochemical detection of 4-nitrobenzaldehyde. The electrocatalytic response was measured using differential pulse voltammetry techniques and cyclic voltammetry, where the linear concentration range of analyte detection was estimated to be 0-900 μM and the detection limit was 0.233 μM with high selectivity toward the analyte. The sensor demonstrated repeatability and stability, allowing the direct electroanalytical measurement of 4-nitrobenzaldehyde in real samples with reliable recovery. This methodology expands the application of porphyrin MOFs for the electroanalytical sensing of environmental contaminants.

Novel electrochemical sensing strategy for ultrasensitive detection of tetracycline based on porphyrin/metal phthalocyanine-covalent organic framework

In this work, a novel two-dimensional semiconducting metal covalent organic framework (CuTAPc-TFPP-COF) was synthesized and used as biosensing platform to construct aptasensor for trace detection of tetracycline (TC). The CuTAPc-TFPP-COF integrates the highly conjugated structure, large specific surface area, high porosity, abundant nitrogen functional groups, excellent electrochemical activity, and strong bioaffinity for aptamers, providing abundant active sites to effectively anchor aptamer strands. As a result, the CuTAPc-TFPP-COF-based aptasensor shows high sensitivity for detecting TC via specific recognition between aptamer and TC to form Apt-TC complex. An ultralow detection limit of 59.6 fM is deduced from the electrochemical impedance spectroscopy within a wide linear range of 0.1-100000 pM for TC. The CuTAPc-TFPP-COF-based aptasensor also exhibits good selectivity, reproducibility, stability, regenerability, and excellent applicability for real river water, milk, and pork samples. Therefore, the CuTAPc-TFPP-COF-based aptasensor will be promising for detecting trace harmful antibiotics residues in environmental water and food samples.

Construction of Porphyrin-Based Bimetallic Nanomaterials with Photocatalytic Properties

The efficient synthesis of nanosheets containing two metal ions is currently a formidable challenge. Here, we attempted to dope lanthanide-based bimetals into porphyrin-based metal-organic skeleton materials (MOFs) by microwave-assisted heating. The results of the EDX, ICP, and XPS tests show that we have successfully synthesized porphyrin-based lanthanide bimetallic nanosheets (Tb-Eu-TCPP) using a household microwave oven. In addition, it is tested and experimentally evident that these nanosheets have a thinner thickness, a larger BET surface area, and higher photogenerated carrier separation efficiency than bulk porphyrin-based bimetallic materials, thus exhibiting enhanced photocatalytic activity and n-type semiconductor properties. Furthermore, the prepared Tb-Eu-TCPP nanomaterials are more efficient in generating single-linear state oxygen under visible light irradiation compared to pristine monometallic nanosheets due to the generation of bimetallic nodes. The significant increase in catalytic activity is attributed to the improved separation and transfer efficiency of photogenerated carriers. This study not only deepens our understanding of lanthanide bimetallic nanosheet materials but also introduces an innovative approach to improve the photocatalytic performance of MOFs.

3D Lanthanide Neodymium Porphyrin Metal-Organic Framework for Photocatalytic Oxidation of Styrene

A novel three-dimensional lanthanide porphyrin-based MOF (Nd-PMOFs) was synthesized by using tetracarboxyphenyl porphyrin as the ligand and the lanthanide Nd as the coordination metal. Its specific crystal structure information was obtained by single-crystal diffraction with the space group C2/c and the empirical formula C₇₂H₄₅N₆Nd₂O_15.25. This new Nd porphyrin-based MOF with an organic framework formed by a unique coordination method enables the effective separation of photogenerated electrons and holes under photoluminescence, giving it excellent photocatalytic property which could be verified by the characterization data. The photocatalytic performance was examined by taking tert-butyl hydroperoxide as the oxidant and Nd-PMOFs as the catalyst for photocatalytic oxidation of styrene to benzaldehyde with 91.4% conversion and 81.2% benzaldehyde selectivity under optimal reactions, which surpasses most of the results reported in the literature. Several styrenes with other substituents were screened to explore the general applicability of Nd-PMOF for photocatalysis of styrene, among which Nd-PMOFs also exhibited excellent photocatalytic performance. This work offers the possibility to apply lanthanide organometallic frameworks, which are widely used in fluorescent materials, to photocatalysis. In addition, it also provides a new method for the catalytic generation of benzaldehyde from styrene that is consistent with the needs of modern green development.

Electrocatalytic Porphyrin/Phthalocyanine-Based Organic Frameworks: Building Blocks, Coordination Microenvironments, Structure-Performance Relationships

Metal-porphyrins or metal-phthalocyanines-based organic frameworks (POFs), an emerging family of metal-N-C materials, have attracted widespread interest for application in electrocatalysis due to their unique metal-N4 coordination structure, high conjugated π-electron system, tunable components, and chemical stability. The key challenges of POFs as high-performance electrocatalysts are the need for rational design for porphyrins/phthalocyanines building blocks and an in-depth understanding of structure-activity relationships. Herein, the synthesis methods, the catalytic activity modulation principles, and the electrocatalytic behaviors of 2D/3D POFs are summarized. Notably, detailed pathways are given for modulating the intrinsic activity of the M-N4 site by the microenvironments, including central metal ions, substituent groups, and heteroatom dopants. Meanwhile, the topology tuning and hybrid system, which affect the conjugation network or conductivity of POFs, are also considered. Furthermore, the representative electrocatalytic applications of structured POFs in efficient and environmental-friendly energy conversion areas, such as carbon dioxide reduction reaction, oxygen reduction reaction, and water splitting are briefly discussed. Overall, this comprehensive review focusing on the frontier will provide multidisciplinary and multi-perspective guidance for the subsequent experimental and theoretical progress of POFs and reveal their key challenges and application prospects in future electrocatalytic energy conversion systems.

Solution Adsorption of Fluorinated Zinc Phthalocyanines on Titania: Combined XPS, UV-Vis, and Contact Angle Study

The equilibrium solution adsorption of perfluorinated metal phthalocyanines F_XPcZn (x = 16, 64) on titania was investigated. This method was explored as an alternative to the frequently used vapor deposition technique for the preparation of solid-supported phthalocyanines for applications such as sensitizers, catalysts, and sensors. According to X-ray photoelectron spectroscopy (XPS), UV-vis, and water contact angles, the adsorption of phthalocyanines from acetone solution occurred readily at room temperature resulting in the formation of hydrophobic surfaces of the solid-supported phthalocyanines. The adsorption isotherms (298 K) were of the Langmuir-type with saturation plateau. The effective thickness of the adsorbed layers at the plateau regions was estimated at 0.17 nm (F₁₆PcZn) and 0.47 nm (F₆₄PcZn), which, assuming the face-down orientation of phthalocyanines, corresponded to ∼52 and ∼77% of the complete monolayers, respectively. In the case of F₆₄PcZn, the state of the adsorbed molecules was similar to that of bulk F₆₄PcZn, suggesting only weak adsorption interactions of dispersive type. In contrast, F₁₆PcZn showed strong interactions with the surface of titania including the dissociation of C-F bonds, i.e., chemisorption. The difference in the adsorption interactions of F₁₆PcZn vs F₆₄PcZn was attributed to the presence of eight i-C₃F₇ groups decorating the perimeter of the F₆₄PcZn molecule. These bulky substituents in the peripheral positions sterically protected the nonperipheral fluorine atoms, thereby preventing their substitution and any other specific interactions between the macrocycle and the surface OH groups.

Metalloporphyrin Metal–Organic Frameworks: Eminent Synthetic Strategies and Recent Practical Exploitations

The emergence of metal–organic frameworks (MOFs) in recent years has stimulated the interest of scientists working in this area as one of the most applicable archetypes of three-dimensional structures that can be used as promising materials in several applications including but not limited to (photo-)catalysis, sensing, separation, adsorption, biological and electrochemical efficiencies and so on. Not only do MOFs have their own specific versatile structures, tunable cavities, and remarkably high surface areas, but they also present many alternative procedures to overcome emerging obstacles. Since the discovery of such highly effective materials, they have been employed for multiple uses; additionally, the efforts towards the synthesis of MOFs with specific properties based on planned (template) synthesis have led to the construction of several promising types of MOFs possessing large biological or bioinspired ligands. Specifically, metalloporphyrin-based MOFs have been created where the porphyrin moieties are either incorporated as struts within the framework to form porphyrinic MOFs or encapsulated inside the cavities to construct porphyrin@MOFs which can combine the peerless properties of porphyrins and porous MOFs simultaneously. In this context, the main aim of this review was to highlight their structure, characteristics, and some of their prominent present-day applications.

Photocatalytic degradation of gaseous benzene using metal oxide nanocomposites

Rapid industrial growth has been accompanied by the pollution of hazardous volatile organic pollutants (VOCs) in air. Among various options available for the treatment of VOCs, the use of metal oxide composites as photocatalysts has been adopted preferably due to their potential to induce the synergistic interactions between the metal nanoparticles (NPs) and metal oxides (especially titanium dioxide (TiO₂)). In this context, an in-depth review is offered to describe the fundamental mechanism of metal oxide-based photocatalysis for the oxidation of gaseous benzene as a model VOC. The discussion has been extended further to evaluate their performances in terms of key performance metrics (e.g., quantum yield (QY), space-time yield (STY), and figure of merit (FOM)). The TiO₂-based metallic bi-component photocatalysts (e.g., Sr₂CeO₄/TiO₂) generally exhibited better photodegradation efficiency with enhanced light absorption capability than monometallic-TiO₂ (e.g., Pd-TiO₂) composites or other modified photocatalysts (e.g., metal-organic framework (MOF)-based composites). Finally, we address the current challenges and future perspectives in this highly challenging research field.

Recent Advances in Porphyrin-Based Systems for Electrochemical Oxygen Evolution Reaction

Oxygen evolution reaction (OER) plays a pivotal role in the development of renewable energy methods, such as water-splitting devices and the use of Zn–air batteries. First-row transition metal complexes are promising catalyst candidates due to their excellent electrocatalytic performance, rich abundance, and cheap price. Metalloporphyrins are a class of representative high-efficiency complex catalysts owing to their structural and functional characteristics. However, OER based on porphyrin systems previously have been paid little attention in comparison to the well-described oxygen reduction reaction (ORR), hydrogen evolution reaction, and CO2 reduction reaction. Recently, porphyrin-based systems, including both small molecules and porous polymers for electrochemical OER, are emerging. Accordingly, this review summarizes the recent advances of porphyrin-based systems for electrochemical OER. Firstly, the electrochemical OER for water oxidation is discussed, which shows various methodologies to achieve catalysis from homogeneous to heterogeneous processes. Subsequently, the porphyrin-based catalytic systems for bifunctional oxygen electrocatalysis including both OER and ORR are demonstrated. Finally, the future development of porphyrin-based catalytic systems for electrochemical OER is briefly prospected.

Three-dimensional Cd(ii) porphyrin metal–organic frameworks for the colorimetric sensing of Electron donors

Three MOFs with metalloporphyrin lined, large square 1D channels were used as colorimetric sensors for electron donors. Exposure to amine vapours caused a redshift of the Soret absorption bands of the metalloporphyrin.

Coordination framework materials fabricated by the self-assembly of Sn(IV) porphyrins with Ag(I) ions for the photocatalytic degradation of organic dyes in wastewater

Two porphyrin-based coordination frameworks, [Ag2(TPyP)Sn(OH)2](NO3)2●(solv)x (1) and [Ag2(TPyP)Sn(INA)2](OTf)2●(CH3CN)2 (2) (INA = isonicotinato anion, OTf = CF3SO3-), were constructed by the self-assembly of hexacoordinated (meso-tetra-(4-pyridyl)porphyrinato)Sn(IV) building blocks with Ag(I) ions. They...

Porphyrin-Containing MOFs and COFs as Heterogeneous Photosensitizers for Singlet Oxygen-Based Antimicrobial Nanodevices

Visible-light irradiation of porphyrin and metalloporphyrin dyes in the presence of molecular oxygen can result in the photocatalytic generation of singlet oxygen (¹O₂). This type II reactive oxygen species (ROS) finds many applications where the dye, also called the photosensitizer, is dissolved (i.e., homogeneous phase) along with the substrate to be oxidized. In contrast, metal-organic frameworks (MOFs) are insoluble (or will disassemble) when placed in a solvent. When stable as a suspension, MOFs adsorb a large amount of O₂ and photocatalytically generate ¹O₂ in a heterogeneous process efficiently. Considering the immense surface area and great capacity for gas adsorption of MOFs, they seem ideal candidates for this application. Very recently, covalent-organic frameworks (COFs), variants where reticulation relies on covalent rather than coordination bonds, have emerged as efficient photosensitizers. This comprehensive mini review describes recent developments in the use of porphyrin-based or porphyrin-containing MOFs and COFs, including nanosized versions, as heterogeneous photosensitizers of singlet oxygen toward antimicrobial applications.

CO2 hydrogenation over functional nanoporous polymers and metal-organic frameworks

CO₂ is one of the major environmental pollutants and its mitigation is attracting huge attention over the years due to continuous increase in this greenhouse gas emission in the atmosphere. Being environmentally hazardous and plentiful presence in nature, CO₂ utilization as C1 resource into fuels and feedstock is very demanding from the green chemistry perspectives. To accomplish this CO₂ utilization issue, functional organic materials like porous organic polymers (POPs), covalent organic frameworks (COFs) as well as organic-inorganic hybrid materials like metal-organic frameworks (MOFs), having characteristics of large surface area, high thermal stability and tunability in the porous nanostructures play significant role in designing the suitable catalyst for the CO₂ hydrogenation reactions. Although CO₂ hydrogenation is a widely studied and emerging area of research, till date review exclusively focused on designing POPs, COFs and MOFs bearing reactive functional groups is very limited. A thorough literature review on this matter will enrich our knowledge over the CO₂ hydrogenation processes and the catalytic sites responsible for carrying out these chemical transformations. We emphasize recent state-of-the art developments in POPs/COFs/MOFs having unique functionalities and topologies in stabilizing metallic NPs and molecular complexes for the CO₂ reduction reactions. The major differences between MOFs and porous organics are critically summarized in the outlook section with the aim of the future benefit in mitigating CO₂ emission from ambient air.

Ligands as copper and nickel ionophores: Applications and implications on wastewater treatment

Modern society depends on many finite natural resources, from which metals are of great importance. Copper and nickel's relevance is due to their vast applications, resulting in high market value and demand. As such, their polluting emissions are also significant and their removal from wastewaters is imperative. Moreover, effluent treatment techniques can be used to recover the metallic cations, via selective processes. In this review, copper and nickel selective ligands in the literature are surveyed. These are most commonly Schiff bases, along with crown ethers and porphyrins. They are usually employed in ion sensing (colorimetric chemosensors or electrodes) with great success - the disruption in response of colorimetric sensors is up to 7% and binding constants are usually at least one order of magnitude greater with the desired cation than with interferents. However, modified adsorbents are also reported. The possibilities of using ionophores in wastewater cleaning, allowing the treatment of effluents and the selective recovery of valuable materials, and their implications on new green policies is discussed.

Porphyrin and phthalocyanine-based metal organic frameworks beyond metal-carboxylates

Given the ubiquitous role of porphyrins in natural systems, these molecules and related derivatives such as phthalocyanines are fascinating building units to achieve functional porous materials. Porphyrin-based MOFs have been developed over the past three decades, yet chemically robust frameworks, necessary for applications, have been achieved much more recently and this field is expanding. This progress is partially driven by the development of porphyrins and phthalocyanines bearing alternative coordinating groups (phosphonate, azolates, phenolates…) that allowed moving the related MOFs beyond metal-carboxylates and achieving new topologies and properties. In this perspective article we first give a brief outline of the synthetic pathways towards simple porphyrins and phthalocyanines bearing these complexing groups. The related MOF compounds are then described; their structural and textural properties are discussed, as well as their stability and physical properties. An overview of the resulting nets and topologies is proposed, showing both the similarities with metal-carboxylate phases and the peculiarities related to the alternative coordinating groups. Eventually, the opportunities offered by this recent research topic, in terms of both synthesis pathways and modulation of pore size and shape, stability and physical properties, are discussed.

MOF/COF-based materials using 3D printing technology: applications in water treatment, gas removal, biomedical, and electronic industries

We have considered the newest outcomes in the uses of 3D-printed COF- and MOF-based materials for diverse applications.

Porphyrin-based frameworks for oxygen electrocatalysis and catalytic reduction of carbon dioxide

The recent progress made on porphyrin-based frameworks and their applications in energy-related conversion technologies (e.g., ORR, OER and CO₂RR) and storage technologies (e.g., Zn–air batteries).

Coordination Polymers Based on Highly Emissive Ligands: Synthesis and Functional Properties

Coordination polymers are constructed from metal ions and bridging ligands, linking them into solid-state structures extending in one (1D), two (2D) or three dimensions (3D). Two- and three-dimensional coordination polymers with potential voids are often referred to as metal-organic frameworks (MOFs) or porous coordination polymers. Luminescence is an important property of coordination polymers, often playing a key role in their applications. Photophysical properties of the coordination polymers can be associated with intraligand, metal-centered, guest-centered, metal-to-ligand and ligand-to-metal electron transitions. In recent years, a rapid growth of publications devoted to luminescent or fluorescent coordination polymers can be observed. In this review the use of fluorescent ligands, namely, 4,4'-stilbenedicarboxylic acid, 1,3,4-oxadiazole, thiazole, 2,1,3-benzothiadiazole, terpyridine and carbazole derivatives, naphthalene diimides, 4,4',4''-nitrilotribenzoic acid, ruthenium(II) and iridium(III) complexes, boron-dipyrromethene (BODIPY) derivatives, porphyrins, for the construction of coordination polymers are surveyed. Applications of such coordination polymers based on their photophysical properties will be discussed. The review covers the literature published before April 2020.

Synthesis and structure of iron–copper/hollow magnetic/metal–organic framework/coordination sites in a heterogeneous catalyst for a Fenton-based reaction

Preparation of novel hybrid catalysts with highly stable properties was conducted for wastewater remediation.