ABSTRACT Advancement in developing smart electronic devices is the need of modern civilization. Schottky diodes, these days, are considered to be one those smart devices due to their enormous applications in diverse field. Metal–ligand coordination compounds having hybrid behavior appeared as an excellent member to serve the field of semiconductor. Structural consistency, unique electronic behavior, and tunable band gap are the key aspects of such compounds. In this perspective, fabrication of Schottky diodes utilizing Zn(II)‐based coordination complexes can be considered as highly significant. Owing to the high abundance of zinc, which makes the implementations of zinc‐based materials cost‐effective, Zn(II)‐complexes can be widely utilized to construct of Schottky diodes. Moreover, coordination complexes based on zinc do not impart high toxicity. Due to these reasons, construction of Schottky diode with Zn(II)‐based coordination complexes can be commercially viable.

Here, we report the synthesis of a binuclear Cd(II) coordination compound, [Cd2(9-aca)4(pyz)(MeOH)3] (1), constructed from the π-conjugated ligand 9-anthracenecarboxylic acid (H-9-aca) and the N-heterocyclic ligand pyrazine (pyz). The compound assembles into a one-dimensional (1D) supramolecular chain through strong π···π stacking interactions. Electrical measurements reveal semiconducting behavior with Schottky diode characteristics, where the enhanced conductivity is attributed to through-space charge transport facilitated by the π···π interactions. The experimental remarks are further corroborated by density functional theory (DFT) calculations with HOMO–LUMO band gap and density of states (DOS) analyses.

The coordination polymers (CPs)/metal-organic frameworks (MOFs) incorporating hetero-bridging ligands have remarkable efficiency and versatility towards fulfilling the objectives of the Sustainable Development Goals (SDGs). In this aspect, two CPs, [Cu2(3-bph)2(adc)4]n (CP1) and [Zn2(3-bph)2(adc)4]n (CP2) (3-bph = (1E,2E)-1,2-bis(pyridin-3-ylmethylene)hydrazine and adc- = 1-adamantanecarboxylate), are characterised, and their significant semiconducting property and selective dye sorption activity are explored. The CPs comprise a secondary building unit (SBU) of a carboxylate-bridging adc- paddle-wheel, [M2(adc)4] (M = Cu(II), Zn(II)), which undergoes pyridyl-N linking by 3-bph to form a 1D chain, where the pyridyl rings undergo π-π interaction to construct a 2D honeycomb-supramolecular network. Interestingly, CP1 demonstrates the selective sorption of methyl red (MR) dye out of four dyes (methylene blue, rhodamine B, methyl red, and methyl orange) with a removal efficiency of 95.37% from aqueous solution within 1 h, whereas CP2 does not show measurable sorption activity. The sorption of CP1 fits the Langmuir isotherm (R2 = 0.9875) and follows pseudo-second-order kinetics, indicating chemisorption on a heterogeneous surface. The DFT calculations using crystallographic parameters determined the band gaps in the semiconducting region (2.39 eV (cal.) and 3.68 eV (exp.) for CP1 and 2.32 eV (cal.) and 3.65 eV (exp.) for CP2). This inspired the measurement of the electrical conductivity from a fabricated Schottky device with thin film electrodes, ITO/CPs/Al. The experiments show that CP2 (5.27 × 10-3 S m-1) has higher electrical conductivity than CP1 (2.72 × 10-3 S m-1) under identical conditions, which explains the superior charge-transport features of CP2 in comparison with CP1. These findings highlight that CP1 serves as a promising material for application as a sustainable MR dye removal agent from wastewater, while both CP1 and CP2 are potential candidates for semiconducting applications.

Achieving self-healing in the photosalient crystals without compromising structural integrity remains a fundamental challenge. So far, self-healing has relied predominantly on a single mechanistic pathway, and systems that integrate multiple cooperative chemical processes are exceedingly rare. Here, we introduce a molecular design strategy that couples the photosalient property with an autogenous self-healing by embedding dynamic covalent disulfide (S–S) linkages into a photoreactive MOF. Using 2-mercaptobenzoic acid, which undergoes in situ oxidation to form S–S bonds during crystallisation, we obtained the 2D MOF. The crystal undergoes cracking followed by a pronounced photosalient motion under UV irradiation. Continued irradiation induces nearly 90% self-healing, acting as a self-healing optical window by restoring optical transparency and single-crystal integrity, as verified by multimodal microscopic techniques and AFM. Comprehensive analysis using single-crystal X-ray diffraction (SXRD), and spectroscopy collectively elucidate the dual mechanisms, such as solid-state [2 + 2] cycloaddition and dynamic covalent chemistry (DCC) (S–S), respectively responsible for the photosalient effect and subsequent autogenous self-healing. This work establishes the first autogenous self-healing in a photosalient MOF with dual chemical phenomenon and demonstrates a rare 2D to 3D transformation operating through an “ SC-crack-heal-SC ” mechanism. This approach opens new avenues for soft robotics, adaptive optics, energy harvesting devices, and resilient next-generation functional materials.

Accurate and selective recognition of ions and molecules is crucial in medical and diagnostic research. Cu(II)- and Zn(II)-based coordination polymers (CPs) have been designed in this work to detect trace levels of melatonin and tryptophan and evaluate their anticancer activity. The [Cu2(4-bph)2(adc)4]n (CP1) (4-bph = (1E,2E)-1,2-bis(pyridin-4-ylmethylene) hydrazine; Hadc = 1-adamantanecarboxylic acid) structure shows that 4-bph serves as a bridging pyridyl-N ligand and adc- is a chelating and binuclear bridging ligand, forming an eight-membered Cu(μ-COO)2Cu motif. In Zn(II)-CP, 4-bph is a bridging ligand, while adc- is monodentate, yielding [Zn(4-bph)(adc)2]n (CP2). In CP1, π-π stacking (∼3.875 Å) and hydrogen bonding generate a 3D supramolecular network while CP2 forms pyridyl-N bridging zigzag 1D CP. The BET analysis measures higher pore volume of CP1 (0.06 cm3 g-1) than CP2 (0.018 cm3 g-1). The CP1 is weakly emissive, and upon irradiation at 312 nm, it emits at 392 nm which has been enhanced by the addition of tryptophan (Trp) (LOD, 44.65 nM), in the presence of 19 other amino acids. The CP1 senses melatonin (MEL) (LOD, 38 nM) also in the presence of various proteins, enzymes, and neuroactive metal ions. Blood serum is used for the measurement of melatonin in blood serum (pH 7.4) and also tryptophan measurement in milk. The CP2 is inactive toward sensing performance. DFT computation using crystallographic parameters reveals a stronger binding of CP1 with Trp (-221 kcal mol-1) than that of CP2 (-38.22 kcal mol-1). Anticancer assays show that CP1 is more potent than CP2 against MCF-7 breast cancer cells, IC50 values are 196.8 ± 2.31 nM (CP1) and 258.2 ± 2.08 nM (CP2). Both CPs exhibit minimal toxicity toward normal PBMCs at these doses. Theoretical evaluation has also been used to explain the luminescence and selective sensing behavior to Trp and MEL.

Framework-stabilized metal nanostructures have emerged as a powerful class of catalysts, offering excellent activity, selectivity, and long-term stability. Encapsulation of nanoparticles (NPs) within porous crystalline frameworks such as metal–organic frameworks (MOFs) and covalent organic frameworks (COFs) effectively prevents aggregation, ensures accessibility of active sites, and enables efficient charge separation. This review provides a comprehensive analysis of synthesis protocols: in situ, post-synthetic, and one-pot methods, keeping in mind the crucial factors that dictate structural architectures. The role of reducing agents, solvents, functional groups, temperature, and framework nanoparticle interactions acts as the pivotal role in the structure–activity relationship. The stimulating role of such a catalyst system can be employed in the field of clean energy and sustainable development: hydrogen evolution reaction (HER), CO2 reduction (CO2RR), selective oxidation, and organic transformations are critically discussed to establish active materials in such applications. In particular, the challenges related to uniform encapsulation, framework stabilisation under reaction conditions, scalability, and recyclability are significantly accessed, together with future prospects in defect engineering, hybrid bimetallic systems, and enhanced light-harvesting abilities. Therefore, this review aims to provide an overview of catalysis, energy conversion, and materials science with a consolidated perspective on the fabrication of next-generation hierarchical frameworks.

The co-crystallization of active pharmaceutical ingredients (APIs) is one of the effective techniques for improving drug efficiency, increasing bioavailability, selective and specific physicochemical challenges associated with solid phase drug formulation and drug action. Pyridine-4-carbaldehyde isonicotinoylhydrazone (PCI) and 2-methylfumaric acid (2MFA), two prominent APIs, create a more stable, lower melting and lower-energy crystalline lattice of the composition, PCI:2MFA, than the individual components. The structural features of the cocrystal conformation, interaction maps, and the extent of non-covalent interactions have been analysed using CSD data. It forms a stable honeycomb-like framework and is sustained by hydrogen bonds and pi-interactions. Comparison with gas-phase calculations revealed charge redistribution during cocrystallization and its effect on intermolecular interactions, bond distances, and electron densities within the hetero-synthon. Because of antimicrobial efficiency of isoniazid and its derivatives the biological activity of PCI, 2MFA and PCI:2MFA have been examined and it has observed that PCI:2MFA is a competent drug against Escherichia coli (zone inhibition diameter, 18.03 +/- 0.15 mm). Therefore, this research supports that cocrystallisation represents a promising policy in drug discovery, enabling the formulation of exploring biologically more potent compounds than that of individual components and expanding applications across diverse biomedical fields.

ABSTRACT In the field of photocatalysis, coordination polymers (CPs) provide a dynamic and promising platform that offers unmatched flexibility in structural design and functioning. Their ability to integrate catalytic activity, charge transport, and light‐harvesting inside a structure they are perfect for a variety of energy and environmental applications due to their architecture. Through regulated architectures that span from 1D chains to 3D frameworks, these materials, which are composed of metal ions or metal clusters joined by organic ligands, offer exact control over their optical and catalytic capabilities. Recent advances in synthetic techniques and ligand design have enabled CPs with greater stability under photocatalytic conditions, efficient charge separation, and enhanced light absorption. These qualities make them attractive options for uses including carbon dioxide reduction, water splitting for hydrogen production, organic transformation and environmental cleanup. Additionally, CPs can be customized for certain photocatalytic reactions because to structural flexibility and the potential to incorporate functional components. The design principles, structure–property correlations, and recent advancements in catalytic performance of CPs as functional structures in photocatalysis are reviewed in this article. The difficulties and opportunities for creating highly effective CP‐based photocatalysts are also covered, with a focus on how they might help with environmental preservation and sustainable energy conversion.

The strategic design of advanced sensing materials for pesticides is increasingly challenged by regulatory restrictions and limited experimental accessibility to several hazardous agrochemicals. This work reports a comprehensive theoretical investigation of a well-characterized Co(II)-based coordination polymer (CP), synthesized using a slow diffusion process, as a potential sensing platform for pesticide recognition. The CP has been thoroughly characterized by X-ray single-crystal diffraction analysis, and its interaction with nine representative pesticides has been systematically explored using density functional theory (DFT) and time-dependent DFT. Optimized host-guest geometries reveal favorable binding affinities driven by a combination of hydrogen bonding, electrostatic interactions, π-interactions, etc., depending on the chemical nature and molecular structure of the pesticide. Optical response, chemical reactivities, charge transfer characteristics, frontier molecular orbital analysis, and noncovalent interaction (NCI) analyses provide molecular-level insights into the recognition mechanism and relative selectivity of the CP toward different pesticides. The results demonstrate that the electronic structure of the Co(II) coordination framework is sensitively modulated upon guest binding, highlighting its potential as a sensing material. This study establishes a predictive computational sensing strategy for environmentally relevant pesticides that are difficult to access experimentally (sometimes banned) and offers valuable guidelines for the future design of CP-based sensors targeting emerging and regulated contaminants.

A new zinc(II) complex [Zn(L)(SCN)2] (1) of NNN donor Schiff base ligand L (where "L" = N-(4,6-dimethyl-pyrimidin-2-yl)-N '-pyridin-2-ylmethylene-hydrazine) is synthesized and characterized by elemental analysis and single crystal X-ray crystallography (XRD). Using the single-crystal X-ray diffraction technique, the structure of Complex 1 exhibits a distorted trigonal bipyramidal geometry. The crystal packing of 1 exhibits intermolecular S & ctdot;H, It & ctdot;It stacking interactions to generate a 1D network. These unique S & ctdot;H interactions significantly affect the stability, arrangement, and prospective functional uses of the Complex. DFT calculations were used to determine the complex's electronic structure, using the pseudo-potential LANL2DZ for the zinc atom and the 6-31G+(d,p) basis set for the remaining atoms, at the B3LYP level. At this computational level, the optimized structure can accurately replicate the crystal structure. To comprehend the complex's reactivity properties, the molecule's electrostatic potential (MEP) and frontier molecular orbital analysis have been assessed. Natural bond orbital (NBO) analysis was used to illustrate the charge transfer between donor and acceptor sites. Additionally, fingerprint plots and Hirshfeld surface analysis are used to examine the complex's intermolecular interactions. Hirshfeld surface analysis, combined with two-dimensional fingerprint plots, provided a comparative visualization of the non-covalent interaction patterns in the synthesized complex.

Dynamic photoactuating crystals are making waves for their ability to transform industries, offering groundbreaking possibilities in fields such as medical technology, robotics, and flexible electronics. These crystals respond to light, enabling innovations such as smart devices, artificial muscles, molecular machines, sensors, and microrobots, heralding a new era of highly adaptive and efficient technologies. Herein, we report two iso-structural metal-organic crystals [Cd(quin)2(4-nvp)2] and [Zn(quin)2(4-nvp)2] [Hquin = quinoline-2-carboxylic acid and 4-nvp = 4-(1-naphthylvinyl)pyridine] based on Cd(II) and Zn(II) ions respectively, that undergo solid-state photochemical [2 + 2] cycloaddition reaction accompanied by photosalient (PS) effect, wherein both the crystals show popping, swelling, and splitting upon UV irradiation, explicitly probed by nanoindentation studies. Thus, these findings may pave the way for the fabrication of photoactuating smart materials.

Correction for 'Structure-directing effect of terephthalate in bridging Zn(II)- and Cd(II)-based coordination polymers towards application in the detection of trace quantities of Pd2+ in aqueous media and their electrical conductivities' by Koushik Saha et al., Dalton Trans., 2025, https://doi.org/10.1039/d4dt03075c.

Utilization of different kinds of materials in the fabrication of electronic device is considered as one of their most prominent employments. For modern civilization development of efficient electronic devices is extremely helpful not only due to their technological aspect but also for their laboratory to land applications. Keeping in mind of the above issues, a copper(II)-based zigzag one dimensional coordination polymer [Cu(4-dpds)(4-cba)2]n(where 4-dpds represents 1,2-di(pyridine-4-yl)disulfane and 4-cba represents 4-chloro benzoate anion) has been synthesized and well-characterized through X-ray single crystal diffraction analysis, XPS analysis, SEM analysis, powder X-ray diffraction analysis, thermogravimetric analysis, absorption spectral analysis and infra-red spectral analysis. Structural characterization through single crystal X-ray diffraction analysis reveals that the zigzag wave like architecture has been generated due to the presence of S-S linked ligands (4-dpds) and strong hydrogen bonding interactions play pivotal role in the development of the supramolecular aggregate. Interestingly, the optical band-gap (2.15 eV) obtained from absorption spectra and the electrical conductivity at room temperature (measured as 9.73 x 10-4 S cm- 1 ) revealed the semiconducting nature of the coordination polymer. The theoretical calculation projected HOMO-LUMO energy gap (2.11 eV) and the Fermi level (near to valence band) estimated from DOS also justified the p-type behavior of the derived material. The device fabricated by sandwiching the coordination polymer in between ITO coated glass substrate and metallic aluminum, was observed to exhibit non-linear rectifying nature in current-voltage characteristic plot. Therefore, it is obvious that these kinds of easily synthesizable lower dimensional coordination polymers can be considered as potential candidates in the fabrication of Schottky like devices and also helpful for technological advancement as well as for the up- gradation of future research in the corresponding field.

Energy crisis and environmental pollution are two central themes of contemporary research towards achieving sustainable development goals (SDGs).

Two-dimensional coordination polymers (2D CPs), featuring unique structural architectures and outstanding electrical properties, are being explored for the fabrication of active electronic devices such as Schottky barrier diodes (SBDs), solar cells, light-emitting diodes (LEDs), field-effect transistors (FETs), and electronic sensors. Highly conjugated and redox-active ligands are among the most preferred candidates for constructing conductive 2D CPs because of their ability to facilitate efficient charge transport. Additionally, structural simplicity and long-term crystallinity are critical factors that contribute to the performance and stability of these materials in electronic applications. In this Frontier article, we review the rationality of structure-property relationships that underpin the enhanced electrical conductivity and practical applicability of 2D CPs in electronic devices. The semiconducting properties of these CPs are strongly modulated by secondary interactions, such as π⋯π stacking, layer-to-layer hydrogen and halogen bonding interactions and van der Waals forces. Therefore, this article aims to make significant contributions to the researchers working in the area of 2D materials with electronic interfaces and technological advancements. Additionally, this approach holds significant promise for addressing environmental challenges and the energy crisis aspects that are highlighted in this article.