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In this study, we report the syntheses of two new coordination polymers (CPs) of Mn(II) and Co(II), [Mn(4-avp)2(adc)(H2O)]·(solvent)x(1) and [Co(4-avp)2(adc)(CH3OH)2] (2), respectively, using relatively less explored linear linker acetylenedicarboxylic acid (H2adc) and polyaromatic hydrocarbon (PAH)–based monodentate N-donor ligand 4-[2-(9-anthryl)vinyl]pyridine (4-avp). CP1creates a two-dimensional (2D) structure in this instance, while CP2is made up of a 1D chain polymer. It is of interest that CP1and CP2exhibit semiconducting behavior and behave as Schottky barrier diodes. However, CP1exhibits higher conductivity and better Schottky diode formation when compared to CP2, which relates to the charge transportation through space via π···π interactions present in CP1. The experimental results are well validated by theoretical density functional theory (DFT) prediction based on band gap and density-of-state (DOS) calculations. It is noteworthy that fabrication of Mn/Co-based Schottky devices appears to be inadequate in the literature. Thus, this work showcases a new direction for the development of electronic device fabrication.

Six coordination polymers of Zn(II)/Cd(II)/Co(II) have been synthesized using the same N,N-donor ligand, namely, N′-(1-(pyridine-3-yl)ethylidene) isonicotinohydrazide (3-pei) and two aromatic dicarboxylates, namely, terephthalate (tp2–) and tetrabromo-terephthalate (tbtp2–). The single-crystal structural analysis reveals a one-dimensional framework interconnected by both sides of the dicarboxylyate linker. Notably, the presence of coordinated water in all compounds prompted an investigation into solvent-dependent structural transformations. The systematic exploration of structural transformations using PXRD confirmed solvent-dependent structural variations. Furthermore, band gap calculations from UV–vis data motivated for an examination of the conductive properties of all compounds. The conductivity study indicates that compared to Zn and Cd complexes, the Co-based complexes (compounds 3and 6) exhibit higher conductance values of 5.76 × 10–4and 1.33 × 10–3Sm–1, respectively, which may be applicable for semiconducting materials. The superior conductance of Co compounds and the solvent-dependent structural transformations of all six compounds are explained by correlating with their respective structures.

The capacity to selectively tune the optical and electrical properties of organic molecules has emerged as an effective strategy for the development of flexible optoelectrical devices. These physical properties are influenced by crystal packing, and as a result, they are expected to vary with polymorphic modifications. Herein, we illustrate the pivotal influence of polymorphism on the optoelectronic traits of the resulting solids, paving the way for prospective applications such as photosensitive Schottky devices. In this study, we isolated two distinct color polymorphs, denoted as Iand II, of a novel Schiff base, (E)-2-methoxy-4-methyl-6-((3-nitrophenyl)iminomethyl)phenol, obtained from the condensation reaction between 2-hydroxy-3-methoxy-5-methylbenzaldehyde and m-nitroaniline. These polymorphs Iand IIwere obtained in pure crystalline forms using different solvents, namely, acetonitrile and methanol, respectively. Analysis via X-ray crystallography unveiled that both forms Iand IIcrystallize within the orthorhombic unit cell, albeit with different space groups of P212121and Pca21, respectively. Notably, the nitro group in these polymorphic forms establishes distinct noncovalent interactions, ensuring the selective stability of each polymorphic form in the solid state with discernible contributions from the solvents. Furthermore, polymorphs Iand IIexhibited reversible thermochromic behaviors between room temperature and low temperature (77 K). Electrical conductivity and photosensitivity studies of the polymorphs revealed that the electrical properties of these polymorphs are significantly different, with notable enhancements observed, particularly for form II, upon illumination with visible light. Our results overall highlight the potential of polymorphic design as a promising avenue for fine-tuning the optoelectrical properties of organic crystalline materials, thereby opening avenues for their utilization in the fabrication of photosensitive devices.

Here, electrical conductivity and explosive sensing properties of multifunctional chromone-Cd(II)-based coordination polymers (CPs) (1–4) have been explored. The presence of different pseudohalide linkers, thiocyanate ions, and dicyanamide ions resulted in 1D and 3D architecture in the CPs. Thin film devices developed from CPs 1–4(complex-based Schottky devices, CSD1, CSD2, CSD3, and CSD4, respectively) showed semiconductor behavior. Their conductivity values increased under photo illumination (1.37 × 10–5, 1.85 × 10–5, 1.61 × 10–5, and 2.01 × 10–5S m–1under dark conditions and 5.06 × 10–5, 8.78 × 10–5, 7.26 × 10–5, and 10.21 × 10–5S m–1under light). The nature of the I–Vplots of these thin film devices under light irradiation and dark are nonlinear rectifying, which has been observed in Schottky barrier diodes (SBDs). All four CPs (1–4) exhibited highly selective fluorescence quenching-based sensing properties toward well-known explosives, 2,4-dinitrophenol (DNP) and 2,4,6-trinitrophenol (TNP). The limit of detection (LOD) values are 55, 28, 27, and 31 µM for TNP and 78, 44, 32, and 41 µM for DNP for complexes 1–4, respectively. A structure property correlation has been established to explain optoelectronic and explosive sensing properties.

Nitroterephthalic acid (NTA)-based supramolecular Co(II)/Cu(II) metallogels were precisely achieved. NTA as the low molecular weight gelator is stoichiometrically combined with respective metal salts to construct Co-NTA and Cu-NTA metallogels in N,N′-dimethylformamide (DMF) medium. The mechanoelastic properties of both metallogels have been meticulously established through the assessment of rheological parameters. The microstructural arrangements within the xerogel samples are intricately elucidated through field emission electron scanning microscopy (FESEM), and this depicts distinct interconnected stacked-like morphological configurations within the supramolecular metallogels. Verification of persisting elements contributing to the metallogel formation is achieved through comprehensive EDX elemental analyses. FTIR spectroscopic analyses dictate the signature of noncovalent interactions for offering an individual stable metallogel network. The possible major repeating unit within the metallogel network is ascertained with the utmost precision through exhaustive ESI mass spectral analyses. The semiconducting behavior of the fabricated metallogels has also been executed. Remarkably, these metallogels exhibit nonlinear J–Vcharacteristics, accompanied by rectification ratios of 102.82 (Co-NTA) and 211.52 (Cu-NTA), underscoring exceptional charge transport attributes for both metallogels. Notably, insights into the Schottky diode parameters of both metallogels and Cu-NTA material display enhanced effective interface mobility, conductivity, and transit time, collectively implying an improved conduction mechanism.

Pyridyl-substituted imidazoquinoline, a potent fluorescent framework, is advantageous to architect multifunctional coordination networks for sensing and fabricating emergent electrical conductors. In this work, a Cd(II)-based one-dimensional (1D) coordination polymer (1D CP), [Cd(glu)2(pbiq)2(H2O)]n(1), [H2glu= glutaric acid and pbiq= 4-(6-(pyridin-4-yl)benzo[4,5]imidazo[1,2-c]quinazoline)], has been structurally confirmed by single-crystal X-ray crystallography. The H-bonding and π···π interactions built a three-dimensional (3D) supramolecular structure that strongly emits at 416 nm in acetonitrile suspension. Potentially intrusive nitroaromatics (NAs) and trinitrophenol (TNP) selectively quench the strong emission of 1, and the highest quenching is noted in the case of TNP. A detection limit (limit of detection (LOD)) of 1.51 × 10–7M for TNP is determined. The band gap (3.31 eV) of 1recognizes semiconducting behavior, and an electronic device is fabricated. The correlation of current vs voltage (I–Vplot) reveals a substantial non-ohmic electrical conductivity of 1(Λ: 1.10 × 10–5S m–1) along with a low energy barrier (ΦB: 0.69), and the series resistance (Rs) becomes 6.21 kΩ.

Two different halides containing chloride- and bromide-assisted dissimilar crystalline supramolecular building blocks of 4′-(1H-imidazol-2-yl)-4,2′:6′,4″-terpyridine (ITP) have been achieved. The dissimilar supramolecular associations with hydrogen-bonded networks have been engineered by the role of halides in the ITP-based crystal systems (i.e., ITP-Cland ITP-Brfor Cl–and Br–, respectively). Hirshfeld surface analyses of these supramolecular assemblies have been performed. The π-systems of protonated pyridine and imidazole rings play a pivotal role in establishing the noncovalent π···π type supramolecular interactions in both the crystals, and the π-system-directed associations certainly assist in forming the 3D supramolecular architectures of ITP-Cland ITP-Brin the solid state. Most intriguingly, the supramolecular association of ITP-Cluniquely stabilizes the cationic unit of hydroxonium hydrate (i.e., H5O2+) in the solid state, and such solid-state stabilization of H5O2+by the imidazole-connected terpyridine-based system is one of the pioneering challenges in crystal engineering. Distinctly, the hydrogen-bonded cluster-like assembly of H5O2+and Cl–has been observed in the ITP-Clsystem through hydrogen donor–acceptor balance. Subsequently, a special drive has been endeavored to unveil the semiconducting features, including the charge transport property and photoresponsive behavior, of these synthesized ITP-Cland ITP-Br-based devices. Fascinatingly, the chloride-mediated ITP-Cl-based device shows remarkably higher electrical conductivity with respect to the ITP-Br-based device under photoirradiation conditions, and this implies the tuning effect of different halides toward the applicability of thin-film-based device performance. The device efficiency-based experimental outcomes have been rationalized through a density functional theory-level analysis.

This work highlights the design, synthesis, structural characterization, electrical conductivities, and hydrogen evolution activities of a new pair of hybrid 3d(Ni)-4f(Ce) block metal complex salts, [Ni(phen)2(NO3)]2[Ce(NO3)6] (1) and [Ni(bpy)3][Ce(NO3)6][Ce(NO3)2(H2O)5]NO3(2) containing phen and bpy ligands; [phen = 1,10-phenanthroline and bpy = 2,2′-bipyridine]. Crystal structural analysis divulges that complex salt 1adopts two units of monocationic Ni(II) complex with one dianionic Ce(IV) complex unit while complex salt 2exists in an association of one unit of dicationic Ni(II) complex with two complex units of Ce along with a counteranionic nitrate. The Ni(II) ions exist in distorted bicapped square pyramidal coordination geometry, while the Ni(II) center in 2exists in an octahedral geometry. The cerium ion in 1exists in dodecahedron geometry while the first and second Ce ions hold dodecahedral and tricapped trigonal prism coordination geometries, respectively. Supramolecular interactions reveal that predominant nonclassical forces like O···H, N···H, π···π, O···π, and O···O are interactive to shape highly ordered crystalline frameworks. Complex salt 2exhibits a unique formation of the supramolecular cage-type framework by the cerium complex units, leading to the inclusion of Ni(II)-complex units into the supramolecular cages. The complex salts (1, 2) were employed to fabricate the Schottky devices to unveil the fate of the hybrid salts in charge transport applications. Carrier mobility (μ) for 1and 2were determined as 3.02 × 10–6and 8.022 × 10–5m2V–1s–1with respective transit time(τ) of 2.60 × 10–7and 9.67 × 10–9s attributing the excellent candidature of complex salt 2in transport properties. The hybrid salts were also found to be highly active electrocatalysts for proton reduction in 1 M aqueous KOH solution at room temperature. The overpotential values of 1and 2were determined to be 730 mV and 687 mV at a current density of 10 mA cm–2with 0.081 s–1and 0.225 s–1as turnover frequencies. The supramolecular interactions–driven crystalline framework sheds light on the electrical conductivities and casting the hydrogen evolution activities for the newly designed hybrid d–f type complex salts.

The two isostructural one-dimensional coordination polymers (1D CPs) [Cu(5-nip)(3-Clpy)2]n(1) and [Cu(5-nip)(3-Brpy)2]n(2) have been synthesized using a 5-nitroisophthalic acid (H25-nip) linker and the meta-substituted 3-chloropyridine (3-Clpy)/3-bromopyridine (3-Brpy) auxiliary ligands. The structural architectures and supramolecular interactions of the CPs have been investigated by single-crystal X-ray diffraction (SCXRD) and density functional theory (DFT) studies, respectively. The SCXRD study reveals that CPs 1and 2form a 1D double-chain structure with carboxylato-bridged cyclic secondary building units (SBUs). Interestingly, both CPs involve type I halogen···halogen (X···X) interactions combined with π···π stacking interactions to generate a three-dimensional (3D) supramolecular network. Moreover, both CPs exhibit interesting X···N π-hole interactions involving a nitro group as the electron acceptor. Both CPs show electrical conductivity in the semiconducting regime and behave as Schottky diodes. However, CP 1has a higher electrical conductivity in comparison to CP 2.

Pyridyl-substituted imidazoquinolines are highly fluorescent probes and are useful for the design of smart materials. A hitherto unknown pyridyl-imidazoquinazoline-coordinated two-dimensional (2D)-Cd(II)-MOF {[Cd2(5-nip)2(pdiq)2(H2O)2(CH3OH)]·H2O}n(CP 1), [H2nip = 5-nitroisophthalic acid and pdiq= 6-(pyridin-4-yl)-5,6-dihydrobenzo[4,5]imidazo[1,2-c]quinazoline] has been designed and structurally confirmed by single-crystal X-ray crystallography. The presence of C–H···π and π···π interactions in CP 1makes it a three-dimensional (3D) supramolecular structure. The excellent luminescent behavior of CP 1is selectively quenched by trinitrophenol (TNP) even in the presence of potentially intrusive nitroaromatic explosives (NAEs). A limit of detection (LOD) of 2.75 × 10–7M for TNP is achieved (3σ/m). In addition, the CP 1displays electrical conductivity on an electronic device with the metal–semiconductor (MS) junction. Current vsvoltage (I–Vplot) correlation reveals the substantial enhancement of electrical conductivity upon illumination (Λ: 1.12 × 10–3S m–1(dark), 6.33 × 10–3S m–1(light)) along with a decrease in energy barrier (ΦB: 0.53 (dark), 0.42 (light)). The plots of log VvslogIshow a non-Ohmic feature at a higher voltage (log V≥ 0) both in the dark and the light phase, which is the characteristic of a Schottky diode barrier (SDB).

Electrochemical reduction of CO2into C-fuels using metal and metal oxides nanoparticles, molecular complexes, etc. is a challenging task in view of a sustainable environment, renewable energy sources, and transformation of waste-to-wealth. Zn(II), d10redox-innocent coordination complexes have recently been used as efficient and selective catalysts in the electroreduction of CO2. Toward this goal, we have synthesized two complexes, tetranuclear (0D) [Zn4(μ4-O)(DABA)6] (1) and polynuclear (1D) [Zn2(DABA)4(4,4′-BPY)]n(2), in one pot (HDABA = 4-diallylamino-benzoic acid and 4,4′-BPY = 4,4′-bipyridine) and characterized them by single-crystal X-ray diffraction measurements and other spectroscopic data. The electroreduction of CO2(CO2RR) using complexes 1and 2as catalysts produced HCOOH, HCHO, and CH3OH. The reduced products are identified by 13C NMR spectral data. It is observed that compound 1is catalytically more efficient than compound 2; when compound 1demonstrates the current −5.63 mA mg–1, compound 2shows a much lower value (−22.27 mA mg–1). Impedance spectroscopy shows that in complex 2, Z′ decreases with a diminishing frequency compared to that of complex 1; this implies that the dc resistivity of 2is lower than that of 1. The theoretically calculated energy gap values (ΔE(HOMO–LUMO)) are 4.4 eV (1) and 2.81 eV (2), and the conductivity is 2.29 × 10–7S/m (1) and 2.54 × 10–3S/m (2). About 104times enhancement of conductivity of 2is due to not only coordination of 4,4′-BPY to Zn(II) but also to subsidization by the coordination polymer and noncovalent superstructure.

Two new families of the electro-conductive two-dimensional (2D) metal organic framework (2D MOFs) of Zn(II)/Cd(II) with the coordination of H25-NIP (5-nitro-isophthalic acid) and INH (isonicotinic hydrazide) are isolated and characterized by different physicochemical techniques. However, crystalline porous structures of {[Zn(5-NIP)2(INH)2]·(DMF)(H2O)2}n(1) and {[Cd(5-NIP)2(INH)2]·(DMF)2(H2O)]}n(2) are analyzed using single-crystal X-ray diffraction techniques. Fascinatingly, the secondary building units (SBUs) of both 1and 2are supramolecularly aggregated arrays with interactions like hydrogen bonding and π···π. Moreover, the geometrical and topological analysis of 1and 2has been elucidated by the TOPOSPRO program package and it symbolizes dia-topology with 4-c uninodal net for 1whereas, sql-topology with a 4-c uninodal net was exhibited for 2. Both these MOFs exhibit significant electrical conductivity with a Schottky diode nature. Out of them, 2promotes the higher charge mobility than 1, which may be due to the larger cation size (Cd(II) (2), 0.97 Å > Zn(II) (1), 0.74 Å) and stronger π–π stacking (distance, 3.511(3) Å (2) and 3.714(4) Å (1)). Furthermore, the analyzed data of transit time, effective carrier mobility, diffusion length, and carrier concentration reveal that 2is transporting charge more efficiently than 1.

Data gathering in wireless sensor networks (WSNs) using mobile sink (MS) reduces the uneven energy consumption of the sensors. However, the data gathering delay increases due to the slow speed of MS. Different MS-based data gathering methods have been proposed to reduce the data gathering delay, but these approaches failed to reduce the delay significantly. In this article, we present a data gathering scheme for single-hop data collection model. It finds a data gathering tour by considering the sensors’ positions, their communication overlaps, and their data availability. Thereafter, the speed and data receiving schedule of the MS are optimized on the tour to ensure maximum data collection is completed in less time. The proposed article not only reduces the data gathering delay but also ensures maximum data collection from all the sensors. Moreover, the effect of the communication range of the sensors and the speed of the MS on the data-throughput are analyzed. Experimental results show that our solution outperforms existing works in terms of data gathering delay, idle-time, and data-throughput.

Internet of Things (IoT) has provided a new horizon to explore numerous application deployment in the pervasive domain. However, due to power, delay and centralized issues of existing IoT-cloud scenario, novel interventions are getting outperformed in many ways. Edge computing has come up with new aspect to mainly minimize the packet transmission delay between the end user device to the remote cloud. Thus, a new way of delay mitigation has been possible. In this study, we conglomerate both the IoT and edge computing to facilitate a proof-of-concept application to application toward serving an e-healthcare scenario. We deploy our application on top of the newly released IoTSim-Edge simulator to diminish the dependency over the physical use of IoT device, sensor and actuators and increase the time to marketize the prototype. In this study, we propose a novel architecture that deals with the e-healthcare application development by using pulse rate monitoring sensor. We also develop activity diagram, class relationship diagram, and configure the engine of the system. We investigate the application against the shrinking factor of the IoT edge, mean execution time, and overall energy consumption by the novel IoT-edgelet modules.

Network-in-a-box (NIB) aims to provide personalized private network services in mission-critical situations. Innovation in business models in industry 4.0 would require NIB to get positioned anywhere and provision seamless Internet connectivity. However, legacy technologies restrict the vision of NIB to become feasible due to the lack of efficient mobility management, portability, all-dimension network coverage and privacy aware service mitigation. In this study, we elaborate on the significance of NIB upon integration with 6G, that is, 6G-NIB for serving actual use cases in the future. We present a visionary augmentation about 6G-NIB on top of vital aspects, such as key requirements, technological aspects, use cases, deployment schemes, variants, and open research issues and future directions. We learn that 6G-NIB would become feasible, reliable and resilient upon true comprehension of earlier aspects. We recommend that applications related to industry 4.0 might benefit from 6G-NIB when proper connectivity features are sought.

In this article, we first provide the basics of ingestibles. Then, we provide a detailed survey on ingestibles as per their applicability in leveraging gastrointestinal disease detection, management, and treatment. Next, we show how ingestibles could be related with the concept of Internet of body. Lastly, we discuss various key challenges and future directions to mitigate these issues.

The present work focuses on energy-neutral, bias-free, scalable galvanic synthesis of highly crystalline thin films of BiOI on a fluorine-doped tin oxide (FTO) electrode (BiOI/FTO). Electrodes as developed were subjected to extensive characterization techniques viz.field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, Raman spectroscopy, atomic force microscopy, X-ray diffractometer, ultraviolet–visible spectroscopy, and other electrochemical techniques to observe physio(electro)chemical correlation between galvanic deposition and electrodeposition. In the next step, these BiOI/FTO electrodes were utilized to develop 3D porous BiVO4/FTO electrodes (termed as g-BiVO4) viaa mild thermochemical process. The g-BiVO4/FTO electrode prepared this way exhibited exceptional photoelectrochemical performance for sulfite oxidation, achieving 1.2 mA cm–2at a bias potential of 1.23 V versusreversible hydrogen electrode (RHE) with the early photocurrent onset (0.21 V vsRHE), as comparable to electrodeposited BiVO4on a FTO electrode (e-BiVO4/FTO). We also fabricated Schottky barrier diode to shed light on the charge-transport mechanism of the g-BiVO4/FTO electrode. In order to improve water oxidation kinetics, we further photodeposited cobalt acetate (CoAc) on the g-BiVO4/FTO electrode. The CoAc-g-BiVO4/FTO electrode, on optimization, showed a photocurrent of 0.73 mA cm–2at 1.23 V under the illumination of 20 mW cm–2blue light-emitting diode with 36 h of sustained water catalytic performance. This demonstrates the importance of galvanic deposition process as an alternative to the high energy-demanding synthesis techniques such as electrodeposition, hydrothermal, and so forth.

The combination of two 8-aminoquinoline-based Schiff base ligands (L1 and L2) with SCN–and Ni(II) has led to the synthesis of two new one-dimensional thiocyanato-bridged coordination polymers: [Ni(L1)(NCS)2]n(1) and [Ni(L2)(NCS)2]n(2). Both compounds are isostructural and consists of regular zigzag thiocyanato-bridged chains with very weak S···S interchain interactions. The measured room-temperature conductivities of compounds 1and 2(7.0 × 10–5and 2.0 × 10–5S m–1, respectively) are indicative of semiconductor behavior which increases in the presence of photoillumination (3.5 × 10–4and 4.9 × 10–4S m–1, respectively). The measured I–Vcharacteristics of compound 1and 2based thin film metal–semiconductor (MS) junction devices under irradiation and nonirradiation conditions show a nonlinear rectifying behavior, typical of a Schottky diode (SD). The rectification ratios (Ion/Ioff) of the SDs in the dark at ±2 V (26.96 and 31.96 for 1- and 2-based devices, respectively) increase to 44.19 and 79.42, respectively, upon light irradiation. The photoinduced behavior has been analyzed by thermionic emission theory, and to determine the diode parameters, the Cheung’s method has been employed. These diode parameters indicate that compound 2has a better performance in comparison to compound 1and that these materials are good candidates for applications in electrochemical devices. Magnetic measurements show that both compounds present ferromagnetic Ni–Ni intrachain and weak antiferromagnetic interchain interactions. The isothermal magnetizations at 2 K show that both compounds are metamagnets with critical fields of ca. 130 mT in 1and 90 mT in 2at 2 K. In the ferromagnetic phase (above the critical field), both compounds exhibit a long-range ferromagnetic order with critical temperatures of around 3.5 K in 1and 3.0 K in 2. DC and AC measurements with different applied DC fields confirm the metamagnetic behaviors and have allowed the determination of the magnetic phase diagram in both compounds.

A heteroporous metal–organic framework, [Cd2(2,2′-DSB)2(INH)2(H2O)2]n(1), is fabricated by the reaction of CdI2, 2-mercaptobenzoic acid (2-MBAH), and isoniazid (INH). The X-ray structure of the compound 1shows the bridging INH and 2,2′-disulfanediyldibenzoic acid (H22,2′-DSBA) around the Cd(II) ion center. 2-MBAH has been in situdimerized to the formation of 2,2′-DSB2–(S–S-bonded dianion), which has further extended to form the 2D network. However, supramolecular assembly via π···π and hydrogen bonds strengthens the structural motif within the 3D array. Optical stimulation generated the thiol radical under an argon environment followed by the electron paramagnetic resonance (EPR) study, but upon exposure to air, the EPR signal gradually disappeared by the formation of the S–S bond, which was commonly known as a self-healing property. Again, compound 1exhibited as a semiconducting material with a band gap of 3.7 eV. The I–Vcharacteristics of 1show that the conductivity is intensified by an optical response. The Schottky diode property of 1shows a lower barrier height, a lower resistance, and a higher conductivity upon illumination at 360 nm.

An intriguing functional supramolecular Tb(III)-metallogel (Tb-OX) is derived through the sonication of terbium(III) chloride hexahydrate and oxalic acid dihydrate in N,N-dimethylformamide (DMF) solvent under ambient conditions. A rheological investigation proves the mechanical stability of the supramolecular Tb-OX metallogel. Field emission scanning electron microscopy (FESEM) microstructural analysis unveils the rocklike morphological pattern of the Tb-OX metallogel having a supramolecular network. Metallogel synthesis, crystallinity, and thermal behavior of Tb-OX are evaluated with the help of IR spectroscopic investigations, powder X-ray diffraction (PXRD), and thermogravimetric analysis (TGA). Exhaustive investigations and analyses of the optical and electrical parameters of Tb-OX establish the semiconducting properties of the Tb-OX metallogel. Based on its conducting properties, the Tb(III)-metallogel is successfully applied to a metal–semiconductor junction-based photosensitive Schottky barrier diode device with excellent charge transport properties.

A newly designed multifunctional two-dimensional coordination polymer (2D CP) {[Cd(suc)(4-nvp)2]·2H2O}n, (1), (H2suc = succinic acid and 4-nvp = 4-(1-naphthylvinyl)pyridine) has been synthesized and characterized by X-ray crystallography. The solid-state structure of the compound 1reveals the formation of three-dimensional supramolecular architecture via C–H···π and π···π stacking interactions. Interestingly, the supramolecular assembly of compound 1exhibits electrical conductivity in the semiconducting nature. A deep insight into the electrical study of compound 1carried out by dielectric characterization reveals the enhancement of conductivity upon light soaking. Thus, the compound has potential applicability in the fabrication optoelectronic devices. On the other hand, compound 1shows sensing activity toward explosive nitroaromatic compounds (epNACs), which threatens devastating terror attacks ultimately responsible for massive loss of life. Besides, the nitroaromatic compound (NAC) 2,4,6-trinitrophenol (TNP) can enter inside the mammalian digestive cycle, wherein it gets metabolized into a mutagenic species, picramic acid, which causes health hazards. Compound 1can detect TNP with the most acceptable fluorescence method. Together with its optoelectronic device fabrication and explosive sensing application, the synthesized material can be used as a potential candidate for sustainability.

Three Cd(II) based coordination polymers (CPs) (1–3) are designed using 3-aminoquinoline and 5-aminoquinoline based Schiff base ligands and thiocyanate and dicyanamide as bridging ligands. Pseudohalide linkers play a crucial role in the architecture of the CPs. These compounds are prepared under an ambient condition with high yield. The I–Vcharacteristics of the 1–3based thin film devices (Al/complex interface) under dark and illumination conditions are nonlinear rectifying nature, which is the signature of a Schottky barrier diode (SBD). The rectification ratio (Ion/Ioff) of the SBDs under dark condition at ±2 V has been obtained as 16.41, 15.48, and 14.73 and under illumination conditions; the same has been evaluated as 67.18, 46.23, and 37.69 for 1, 2, and 3, respectively. The photoresponsivity of the device is found to be 5.52, 2.89, and 2.54 for 1, 2, and 3based SBDs, respectively. The enhancement of conductivity under photoilluminated conditions depends on π-electron donor capacity of Schiff base ligands and the length of pseudohalide linkers of 1–3. Again, depending on the binding fashion of the coordinating ligands, three CPs (1–3) exhibit different selectivity toward nitroaromatic sensing. In 2,4,6-trinitrophenol (TNP) sensing, CPs follow the order 3> 2> 1. CP 3has the highest quenching constant among the other two CPs along with a prominent selectivity and lowest detection limit in response to TNP.

We have synthesized carboxylato-bridged paddle-wheel Cu(II) coordination polymers [Cu2(DABA)4(4,4′-BPY)]n(1) and [Cu4(DABA)8(PYZ)(H2O)2] (2) by varying the axial linkers 4,4′-bipyridine (4,4′-BPY) and pyrazine (PYZ) (HDABA = 4-diallylamino-benzoic acid). The single-crystal X-ray structure of 1is a one-dimensional polymer, while 2is a zero-dimensional tetranuclear Cu(II) complex. Upon light irradiation, the thin film of the compounds increases the electrical conductivity with respect to the dark phase, and the conductivity of 1is ∼150 times higher than 2. Magnetic properties were investigated at an applied field 0.5 T in a temperature range 5–300 K. Compound 1exhibited ferromagnetic behavior, compound 2exhibited antiferromagnetic behavior at 300 K, and the effective magnetic moment at 300 K is 1.94 and 0.93 B.M. respectively. The capability to switch photoelectricity and magnetism by changing the crystal structure via the axial linker’s modification has been rationalized through density functional theory calculations.

A one-dimensional coordination polymer (1D CP), [Cd(bpe)(p-brba)2]n(1), has been synthesized by the slow diffusion method keeping the mixture of Cd(NO3)2·6H2O and 1,2-bis(4-pyridyl)ethylene (bpe) ligand along with para-bromobenzoic acid (p-brba) in the dark. Interestingly, the compound 1undergoes a single-crystal to single-crystal (SCSC) photochemical [2 + 2] cycloaddition reaction to generate dimerized 1D CP [Cd(rctt-tpcb)1/2(p-brba)2]n(2) [rctt-tpcb = rctt-tetrakis(4-pyridyl)cyclobutane]. As a result, π···π stacking interactions among p-brba ligands of adjacent chains have been removed in the dimerized product. This structural transformation has a significant effect on the conductivity of the materials.

Coordination polymers are useful materials in different fields of applications, including the development of supramolecular electrical devices for the use of renewable energy sources. In this work, we have designed two new classes of mixed-ligand one-dimensional coordination polymers (1D CPs) [Zn(ADC)(PBT)2(H2O)2]n(1) and [Zn(Succ)(PBT)2(H2O)2]n(2) (ADC2–, acetylenedicarboxylato; Succ2–, succinato; PBT, 2-pyridin-4-ylbenzothiazole) and characterized them by elemental analysis, infrared spectra (IR), single-crystal X-ray diffraction data, powder X-ray diffraction (PXRD), and thermogravimetric analysis (TGA) data. In the structural motif Zn(II) is bridged by an aliphatic dicarboxylato ligand (ADC/Succ) and two axial positions are occupied by pyridyl-Nof PBT along with water coordination. ADC acts as a monodentate carboxylato-Oligand in compound 1, whereas in 2Succ serves as a carboxylato-O,Ochelator. Compounds 1and 2are both isostructural and construct 3D supramolecular networks by hydrogen bonds (bonding) and π···πinteractions along with weak C–H···π interactions. Fascinatingly, compound 1exhibits an ∼700 times higher Schottky barrier diode (SBD) electrical conductivity (1.31 × 10–2S m–1) in comparison to compound 2(1.80 × 10–5S m–1). The impedance electrical conductivities of 1(1.22 × 10–4S m–1) and 2(3.24 × 10–6S m–1) differ significantly; in addition, the direct current conductivities are 1.08 × 10–4S m–1(1) and 5.55 × 10–6S m–1(2). To shed light on the charge transport mechanism of the compounds, the mobility, transit time, and density of states at a quasi-Fermi level have been evaluated. Linear dicarboxylato bridging with an sp-hybrid acetylene motif may be the reason for faster charge flow in 1in comparison to the sp3hybrid nonlinear succinato bridging compound 2.

A metal–organic compound [Cd(quin)2(4-nvp)2] [1; Hquin = quinoline-2-carboxylic acid and 4-nvp = 4-(1-naphthylvinyl)pyridine] undergoes topochemical [2 + 2] cycloaddition by sunlight irradiation to generate a one-dimensional coordination polymer. This reaction is thermally reversible, and switching between two crystalline forms can be monitored by conductivity measurements.

The porous materials are efficient storage and exchange systems of small molecules and ions. Some of the porous materials may be used as an efficient storage system of iodine. Herein, a honeycomb (hcb)-type 2D+2D (2D = two-dimensional), parallel polycatenated Porous Polycatenated Coordination Polymer (PPCP) {[Cd2I2(BDC)2(INH)2]·(2DMF)(H2O)}n, 1(INH, isoniazid; H2BDC, terephthalic acid; DMF, dimethylformamide) is characterized that reversibly uptakes I2from organic medium (more than 98%). The single-crystal X-ray structure determination reveals the CdIN2O3distorted octahedral geometry, and the microporous channel (∼1.7 nm) is generated by polycatenation along with the supramolecular interaction. On thermal treatment at 120 °C the polymer, 1, loses solvents, while the crystalinity is reserved. The solvent-free activated state of the coordination polymer, [Cd2I2(BDC)2(INH)2]n, 1′, adsorbs N2, and the adsorption–desorption analysis displayed the increase in porosity to mesoporous range (∼14.7 nm) with very high specific Brunauer–Emmett–Teller surface area, which may be due to the rise in interparticle void space. Iodine (I2) sorption studies of mesoporous architecture of 1′show high I2removal efficiency (98.9%), which is revealed from the reversible iodine uptake kinetics study. Typically, uptake of three moles of I2per unit cell associated with color change from colorless to brown is discernible from thermal analysis. Interestingly, the iodine-loaded polymer (I2@1′) shows ∼1.5 times enhancement in electrical conductivity compared to 1′only. The optical band gap obtained from density functional theory (DFT) calculation and the experimental values are 1, 3.48 eV (DFT), 3.70 eV (experimental) and I2@1′, 3.19 eV (DFT), 3.50 eV (experimental). The lowering of band gap after I2sorption is presumably due to the interaction of I2with Cd–I (Cd–I···I–I) in hcb core, which was evidenced from Raman spectra analysis.

A novel mixed ligand one-dimensional coordination polymer (1D CP), {[Cd2(adc)2(4-nvp)6]·(MeOH)·(H2O)}n(1; H2adc = 9,10-anthracenedicarboxylic acid, and 4-nvp = 4-(1-naphthylvinyl)pyridine), has been synthesized and structurally characterized by single crystal X-ray crystallography. The 1D polymer undergoes supramolecular aggregation via hydrogen bonding, C–H···π, and π···π interactions. Interestingly, compound 1shows increasing conductivity upon irradiation of light. Therefore, it has the potential to be used in optoelectronic devices. Moreover, the supramolecular assembly of 1specifically detects Cr3+cation in the presence of other competitive analytes. Most importantly, compound 1exhibits fascinating turn-on Cr3+sensing, which seems to be an ornament in the field of sensing application.

A pair of 4-(1-naphthylvinyl)pyridine (4-nvp) ligands has been successfully aligned in head-to-tail fashion in a one-dimensional (1D) double chain ladder polymer [Cd(adc)(4-nvp)2(H2O)]n(1; H2adc = acetylenedicarboxylic acid) that undergoes a photochemical [2 + 2] cycloaddition reaction accompanied by single-crystal to single-crystal (SCSC) structural transformation from a 1D chain to a 2D layer structure. These structural changes have a significant impact on the conductivity and Schottky nature of the compound.

Two zinc(II) based metal complexes, [Zn(Pymox)Cl2] (1) and [Zn6(Pymox)6(μ2-O)3] (2), where Pymox = 3-[(4,6-dimethyl-pyrimidine-2-yl)-hydrazono]-butan-2-one oxime, have been synthesized and characterized by elemental analysis, IR, and single crystal X-ray diffraction studies. Single crystal X-ray analysis confirms that one of the synthesized products (1) is a mononuclear complex and another (2) is a hexanuclear Zn complex. The optical band gap energy in both the complexes (3.43 eV in 1and 2.36 eV in 2) from solid state UV measurement explores semiconductor behavior of the synthesized materials. The dielectric parameters such as charge transfer resistance, room temperature dc conductivity and electron lifetime measurement shows the superiority of complex 2over complex 1. Therefore, the Schottky barrier diode (SBD) electronic devices were fabricated by using these two complexes with aluminum (Al) and indium tin oxide (ITO) in sandwich configuration—ITO/1or 2/Al. Both the devices exhibit sound rectification behavior with better photosensing property for complex 2based SBD under irradiation of light, in comparison to dark conditions. The electric current measurement for complex 2based SBD also exhibits enhanced photoconduction properties under irradiation of light when current is measured several times under a constant bias voltage by putting light on and off with successive repetitions. The detailed discussion of photo response properties of both the complexes in the solid state device have been reported along with their applicability in photosensitive devices. Finally, DFT calculations have been carried out to rationalize the experimental differences in band gap and conductivity observed for compounds 1and 2.

Syntheses, structural characterizations, photoluminescence, and adsorption properties of three new azo-functionalized Cd(II)-MOFs, namely, {[Cd(azbpy)(msuc)]·2.5(H2O)}n(2), {[Cd(azbpy)(mglu)]·5(H2O)}n(3), and {[Cd1.5(azbpy)2(glu)]·(NO3)·MeOH}n(4) [where msuc2−= methylsuccinate; mglut2−= methylglutarate; glut2−= glutarate; azbpy = 4,4′-azobispyridine] have been reported. The compounds show different structures only with the variation of aliphatic dicarboxylates. The photoswitching behavior for the above-mentioned newly synthesized Cd(II)-MOFs along with one of our previously reported other azo-functionalized Cd(II)-MOF, namely, {[Cd(azbpy)(suc)]·2(H2O)}n(1), has been studied extensively. At photoilluminated condition, the conductivity values can draw a clear structure–property relationship among the structures of compounds 1–4. Single crystal structural analysis reveals that all the compounds exhibit a three-dimensional (3D) framework connected by azbpy linker and respective aliphatic dicarboxylate through their bis-chelating mono/bis oxo-bridging fashion. Compounds 1–3exhibit an iso-structural honeycomb like 3D framework showing the same coordination environments, where the metal-carboxylate 2D sheets of compounds 1–3are pillared by N,N′-donor azbpy linkers. On the other hand, compound 4exhibits a 2-fold interpenetrated 3D framework with a little difference in its coordination environment and the pillaring of 1D metal-carboxylate ladder by azbpy linkers. All the compounds significantly demonstrate their enhanced sensitivity under light rather than the dark condition. The gas and solvent vapor sorption studies have been performed for the synthesized compounds 2–4. Moreover, compound 2exhibits an enhanced type IV selective CO2adsorption isotherm over N2along with the appearance of gate opening phenomena in that.

Metal–organic frameworks (MOFs) are mostly electrically insulating systems. Only recently have there been reports of MOFs showing high conductivity. However, a large void still remains in the fabrication of photoconducting MOFs, which can function under extreme conditions for advanced optoelectronic applications. This issue was addressed by self-assembling an electrically active and luminescent bola-amphiphilic organic linker, dialkoxydodecyl-oligo-(p-phenyleneethynylene)dicarboxylate (OPE-C12), with ZnII, which led to a self-cleaning and semiconducting nanoscale MOF Zn(OPE-C12)·2H2O (NMOF-1). The fabricated device using NMOF-1 showed Schottky barrier behavior along with a 1000- and 1400-fold increase in current at +0.2 V in the absence and presence of light, respectively. A high rectification ratio of 47 and 83 was also observed under dark and photoirradiated condition. Along with high thermal stability, moisture resistance, and luminescence, NMOF-1 can be used in advanced optoelectronics probably even under water, being the first porous MOF material showing such properties.

The advent of Internet of Things (IoT) has shown a new direction of innovative research in agricultural domain. Being at nascent stage, IoT needs to be widely experimented so as to get widely applied in various agricultural applications. In this paper, I review various potential IoT applications, and the specific issues and challenges associated with IoT deployment for improved farming. To focus on the specific requirements the devices, and wireless communication technologies associated with IoT in agricultural and farming applications are analyzed comprehensively. Investigations are made on those sensor enabled IoT systems that provide intelligent and smart services towards smart agriculture. Various case studies are presented to explore the existing IoT based solutions performed by various organizations and individuals and categories according to their deployment parameters. Related difficulties in these solutions, while identifying the factors for improvement and future road map of work using the IoT are also highlighted.

The design of an energy-harvesting unit with superior output characteristics, i.e., high power density, is a great technological challenge in the present time. Here, simple, lightweight, flexible, and cost-effective piezoelectric nanogenerators (PENGs) have been fabricated by integrating the aluminum electrodes onto Er3+/Fe3+stimulated electroactive, visible-light-emitting, and large dielectric PVDF films in which ErCl3·6H2O and Fe(NO3)3·9H2O act as the catalytic agents for electroactive β polymorph nucleation and the enhancement of dielectric properties. The developed PENGs exhibit excellent energy-harvesting performance with very high power density and very fast charging ability compared with the previously reported PVDF-assisted prototype nanogenerators. The PENGs lead to very large power density (∼160 and ∼55.34 mW cm–3) under periodic finger imparting for Er3+- and Fe3+-stimulated PVDF-film-based energy-harvester units, respectively. The fabricated self-powered PENG is also able to light up 54 commercially available light-emitting diodes.

We have investigated the origin of ionic conductivity in methylammonium lead iodide (MAPbI3) by positron annihilation lifetime spectroscopy (PALS), supplemented by coincidence Doppler broadening spectroscopic (CDBS) techniques which reveal the presence of methylammonium (MA+) defects in the perovskite crystal lattice. Crystallinity and the defect concentration vary with the perovskite synthesis process, which in turn governs the magnitude of ionic conductivity. Single-crystalline perovskite contains lesser defects with equal probability of developing both cationic and anionic (halide) vacancies, whereas the polycrystalline perovskite sample developed through mechanical process carries mainly cationic, i.e., MA+vacancy (V′MA) in its crystal lattice as indicated by direct current (dc) polarization experiment.

Internet of Things (IoT) envisages overall merging of several “things” while utilizing internet as the backbone of the communication system to establish a smart interaction between people and surrounding objects. Cloud, being the crucial component of IoT, provides valuable application specific services in many application domains. A number of IoT cloud providers are currently emerging into the market to leverage suitable and specific IoT based services. In spite of huge possible involvement of these IoT clouds, no standard cum comparative analytical study has been found across the literature databases. This article surveys popular IoT cloud platforms in light of solving several service domains such as application development, device management, system management, heterogeneity management, data management, tools for analysis, deployment, monitoring, visualization, and research. A comparison is presented for overall dissemination of IoT clouds according to their applicability. Further, few challenges are also described that the researchers should take on in near future. Ultimately, the goal of this article is to provide detailed knowledge about the existing IoT cloud service providers and their pros and cons in concrete form.

We report herein two multifunctional metal–organic frameworks (MOFs) that exhibit excellent mutually inclusive electrical and magnetic properties. Accordingly, two cobalt and nickel based MOFs (Co-MOF, Ni-MOF) were generated using a flexible bispyrazole based ligand and 2-sulphono terephthalic acid. The idea is to generate paramagnetic metal ion based magnetic MOFs, which can also be used to fabricate electrical devices by utilizing the immobilized free sulfonic groups and encapsulated H-bonded water clusters for active charge species generation and transportation. Further support comes from the intriguing structural features of the MOFs that include extensive H-bonded water clusters, free sulfonic acid moiety, or syn-antibridged carboxylates, which make them highly suitable candidates for generating electrical and magnetic materials. Further complementary support for their candidature comes from the high thermal, chemical, and physical stability of the MOFs. The impedance spectroscopy data and I–Vresults unequivocally support the suitability of the MOFs for electronic device fabrication showing a befitting conductivity value of 1.80 × 10–4S/m with an ideality factor of 1.06 for Ni-MOF. Interestingly, the Co-MOFshows a light-dependent behavior with conductivity values of 9.09 × 10–5S/m (dark) and 6.31 × 10–4S/m (light) and ideality factors of 0.78 (dark) and 0.92 (light). The MOFs, fitted with a free sulfonic acid moiety and extensive H-bonded water clusters, show high potential for proton exchange membrane fuel cells (PEMFCs) development with corroborating proton conductivity values of 1.95× 10–3S/cm and 5.80 × 10–4S/cm for Ni-MOFand Co-MOF, respectively, at 95% relative humidity and 85 °C. Moreover, the interesting structural aspects like syn-antibridged carboxylates prompt us to explore the magnetic behavior of the MOFs. The Ni-MOFshows some interesting antiferromagnetic behavior. The Co-MOFreveals intriguing single molecule magnet behavior with a Ueffvalue of 34 K and moderate relaxation time of 3.5× 10–8s.

The importance of three synthesized metallogels of suberic acid distinctly with nickel, zinc, and cadmium acetate salts has been uncovered. For the creation of these soft materials, N,N′-dimethyl formamide was utilized as a source of the trapped solvent. The synthesized metallogels display intriguing viscoelasticity, and the interpretation of experimental parameters obtained from rheological results advocates the gel behavior. Microstructural analysis combined with energy-dispersive X-ray confirms the occurrence of individual gel-developing constituents as observed in different hierarchical microstructural patterns. Significant variations in microstructural arrangements with diverse extent of supramolecular non-covalent patterns inside gel networks were perceived through field emission scanning electron microscopy, atomic force microscopy, and transmission electron microscopy analyses. Fourier transform infrared and electrospray ionization-mass spectral analyses and powder X-ray diffraction analysis of metallogel samples of different gel-establishing ingredients help to investigate the possible supramolecular interactions dictating the metallogel scaffolds. Thermogravimetric analysis of xerogel samples was collected from the synthesized metallogels to understand the thermal stability. These gel materials were characterized by their potential antibacterial efficiency. The potency of metallogels against selective Gram-positive and Gram-negative bacteria was visualized via a spectrophotometer. Human pathogens like Klebsiella pneumoniae(MTCC 109), Salmonella typhi(MTCC 733), Vibrio parahaemolyticus, Bacillus cereus(MTCC 1272), Lactobacillus fermentum(NCDO 955), and Staphylococcus aureus(MTCC 96) are employed in this study. Apart from the biological significance, our metallogels demonstrate as incredible diode performance of fabricated semiconducting systems, which exhibit a considerable amount of non-linearity demonstrating a non-ohmic conduction mechanism at room temperature in dark conditions. Device fabrication was achieved from these metallogels employing the sandwich model with indium tin oxide-coated glass substrates/metallogel/Al structure.

The simple and small organic compound bis((quinolin-4-yl)methylene)benzene-1,4-diamine (BQD) has been synthesized by a one-step Schiff-base condensation reaction, and it has been characterized by elemental analysis, some standard spectroscopic methods, and the X-ray single crystal diffraction technique. It shows the unique property of photosensitivity with about 10 times increase in electrical conduction under irradiation of visible light of a specific wavelength (700 nm), in comparison to dark conditions. However, UV light (350 nm) or visible light of different wavelength (500 or 600 nm) cannot cause an enhancement in its electrical conduction. The electric current measurement of BQD exhibits its response ability toward visible light but not to UV illumination when current is measured several times under a constant bias voltage by putting light on and off with successive repetitions. Theoretical calculations indicate that a slight conformational change in the CN bond and dihedral angle leading to the increase in planarity in the molecule caused under visible light of a specific wavelength (700 nm) is responsible for its photosensitivity and electrical conductivity. A new molecule (Me2-BQD) with two methyl groups in the central phenyl ring shows lower conductivity in comparison to BQD under visible (700 nm), UV (350 nm) light, and dark conditions.

Over the last few years, there are several methodical and productive ongoing research based on the development of high performing, sustainable, non-hazardous energy harvesting nanogenerators. It is a substantial challenge to construct an energy harvester that has a superior output performance as well as an eco-friendly character. In this work, the utilization of naturally available, biodegradable mud volcano clay from Andaman and Nicobar Islands, India was done to design two simple, portable, cost-effective, biocompatible, eco-friendly piezoelectric nanogenerators (PENGs). In the first place, we developed two types of multifunctional poly-(vinylidene fluoride) (PVDF) thin film incorporated with mortar pestle ground clay nanoparticles (average size of 600–700 nm) for 3 mass% (MP1, MP5, MP10) and ball mill ground nanoparticles (average size of 200–300 nm) for 3 mass% (BM0.5, BM1.0, BM1.5), with large electroactive β crystallinity. The incorporation of clay NPs into the PVDF matrix led to notable nucleation of piezoelectric β crystallite {F(β)} of 80.7% and 84.8% for mortar pestle ground (5% doping) and ball mill ground (1% doping) clay NPs respectively. Using these two multifaceted composite thin films we designed two devices using MP5 (MPENG) and using BM1 (BPENG), which possess good energy harvesting potency, commendable power density values and very fast charging capability. Our MPENG and BPENG generate output voltage of ~ 85 V with a short circuit current of ~ 1.6 μA and output voltage of ~ 125 V with a short circuit current of ~ 1.9 μA, respectively and power densities of 4115 μW/cm3and 7187 μW/cm3respectively, on the application of periodic force by hand. The calculated piezoelectric coefficient d33of MP5 and BM1.0 were 39.75 pC/N and 50.10 pC/N at 50 Hz, respectively. To check the real-life applications, MPENG and BPENG were used to lighten up 25 and 40 no. of blue LEDs when connected a series connection and we charged a 2.2 μF capacitor within few seconds. These nanogenerators could also generate a notable voltage from various body movements like heel pressing, jogging or from vibrations or air flow from various instruments. On further advancement, our proposed devices can be used to power up various self-chargeable portable gadgets in our daily lives and in biomedical fields.

In this paper, we have reported the synthesis of FeS2 of higher band gap energy (2.75 eV) by using capping reagent and its successive application in organic--inorganic based hybrid solar cells. Hydrothermal route was adopted for preparing iron pyrite (FeS2) nanoparticles with capping reagent PEG-400. The quality of synthesized FeS2 material was confirmed by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, Fourier transform infrared, thermogravimetric analyzer, and Raman study. The optical band gap energy and electro-chemical band gap energy of the synthesized FeS2 were investigated by UV--vis spectrophotometry and cyclic voltammetry. Finally band gap engineered FeS2 has been successfully used in conjunction with conjugated polymer MEHPPV for harvesting solar energy. The energy conversion efficiency was obtained as 0.064% with a fill-factor of 0.52. [ABSTRACT FROM AUTHOR]

Tactile internet (TI) has emerged as a new possibility into revolutionizing whole society by involving human beings, communication aspects, and industrial operation. Main purpose of TI is to disseminate perceptual, that is, haptic information to remote industry machines for pouring skills and expertise as if it were actually accomplished by a person in reality. Internet of things is an established tool to serve various smart application development that mainly depends on sensors, actuators, communication technology, and cloud‐based services. Existing studies do not clearly mention the key requirements, architectural standardization and TI enabled functions to transfer haptic information via a suitable communication media. Although 5G has been considered as a valuable core of TI infrastructure, lack of actual implementation and related evidence has raised a dilemma about its effectiveness for industry applications leaving with no direction. In this article, we present architectural and system model‐wise development of tactile internet of things for possible industry application realization. We also present key requirements, functional and optimal aspects of tactile internet of things. Study of potential communication technologies and state‐of‐the‐art study on recent works on TI‐based approaches are paved. Lastly, we present key open challenges and future direction to augment this problem. Tactile IoT architecture ecosystem.

Four new Cu(II)-based hexagonal complexes with the metallomacrocycle formulae [Cu6(5-nip)6(3-py)6(H2O)12] (1), [Cu6(5-nip)6(3-Clpy)6(H2O)12] (2), [Cu6(5-nip)6(3-Brpy)6(H2O)12] (3), and [Cu6(5-nip)6(3-Ipy)6(H2O)12] (4) have been synthesized using 5-nitroisophthalic acid (H25-nip) and pyridine (py)/3-halopyridine (3-Xpy; X = Cl, Br, and I) ligands. The structural features and supramolecular interactions of compounds 1–4have been investigated using the single-crystal X-ray diffraction (SCXRD) technique. Interestingly, the hexagonal complexes undergo hydrogen bonding and π···π stacking interactions to form fascinating two-dimensional (2D) honeycomb-like structures. The synthesized complexes exhibit high electrical conductivity, arising from charge transport through space via π···π contacts. However, complexes containing 3-Brpy (3) and 3-Ipy (4) exhibit photosensitivity due to the presence of halogens with a larger size and lower ionization energy. The conductivity results are also in accordance with the theoretical prediction calculated by density functional theory (DFT) study.

Intriguing properties exhibited by porous coordination polymers (PCPs) have been discussed for a very long time, and the peak of the journey has been reached. Many ways have been introduced side by side to explore in the domain of PCPs with further progress to achieve various functionalities. Multifunctionality by these types of frameworks is one of those interesting features which has also been challenged to produce proper frameworks for exhibiting multiple properties by a single structure. Thus, after judicial choice of two different types of ligands, three coordination polymers {[Cd(1,4-(2-Me)-bix)(glu)]·5(H2O)}n(1), {[Cd2(1,4-(2-Me)-bix)(msuc)]·(H2O)}n(3), and {[Zn(1,4-(2-Me)-bix)(msuc)]·(solvent)x}n(4) have been synthesized and characterized. These three compounds along with one previously reported structurally similar complex {[Zn(1,4-(2-Me)-bix)(glu)]·4(H2O)}n(2) have been used to study gas sorption, electrical properties in dark and light, and luminescence. All the PCPs display different gas adsorptions (CO2, N2, H2) and electrical conductance in both dark and illuminated conditions, which is an indication of multifunctionality shown by these structures. This designed structure and the measured properties of the synthesized complexes have been correlated with each individual framework of the four complexes based on the dicarboxylate flexibility/substitution and the size of the metal ion.