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The synthesis and characterization of the isomeric ruthenium complexes with the general formula cis-and trans-[Ru(trpy)(qc)X]n+(trpy is 2,2′:6′,2″-terpyridine, qc is 8-quinolinecarboxylate, cis-1and trans-1, X = Cl, n= 0; cis-2and trans-2, X=OH2, n= 1) with respect to the relative disposition of the carboxylate and X ligands are reported. For comparison purposes, another set of ruthenium complexes with general formula cis-and trans-[Ru(trpy)(pic)(OH2)]+(pic is 2-picolinate (cis-3, trans-3)) have been prepared. The complexes with a qc ligand show a more distorted geometry compared to the complexes with a pic ligand. In all of the cases, the trans isomers show lower potential values for all of the redox couples relative to the cis isomers. Complexes cis-2and trans-2with six-member chelate rings show higher catalytic activity than cis-3and trans-3. Overall, it was shown that the electronic perturbation to the metal center exerted by different orientation and geometry of the ligands significantly influences both redox properties and catalytic performance.

We demonstrated for the first time without any chemical modification the two-photon absorption (TPA) cross-section can be enhanced and red-shifted to the near-infrared (NIR) region by the ground-state proton-transfer (GSPT) process. Using GSPT, we developed a simple binol-based aggregation-induced emission (AIE)-fluorogenic phototrigger having a large two-photon uncaging cross-section in the “phototherapeutic window”. As a proof of concept, we showed our phototrigger for the release of two different anticancer drugs in the NIR region.

A distributed machine learning technique called federated learning allows numerous Internet of Things (IoT) edge devices to work together to train a model without sharing their raw data. Internet of Vehicular Things (IoVT) are an important tool in smart cities for moving objects, such as knowing the traffic patterns, road conditions, vehicle behavior, etc. To enhance traffic management and optimize routes, federated learning, and IoT must work jointly, which may achieve sustainable development goals (SDG) in many ways. This research outlines a system for federated learning in vehicular networks in smart cities. The suggested architecture considers the difficulties presented by such situations’ restricted network connectivity, privacy issues, and security concerns. The framework employs a hybrid methodology integrating federated learning on a centralized server with local training on individual cars. The proposed framework is assessed based on a real-world dataset from a smart city through IoT devices. The findings demonstrate that the suggested method successfully increases model accuracy while preserving the confidentiality and security of the data. In this investigation, we incorporated the Federated Learning model, which can fetch all the information between arbitrary nodes and derive the Traffic, Fuel Cost, Safety, Parking Cost, and Transportation cost for a better routing approach. The suggested framework can be utilized to increase the effectiveness of the transportation system, decrease congestion in smart cities, and improve traffic management. We employ an improved genetic algorithm (iGA) with generation-dependent even mutation to tackle the emission in the smart environment.

A series of bis-tridentate ruthenium complexes was designed to feature opposite localizations of their lowest metal-to-ligand charge transfer (MLCT) excited states, relative to a carboxylic acid that served as a binding group to mesoporous NiO. The purpose was to study the effect of MLCT direction on the rates of hole injection into NiO and subsequent charge recombination. Surprisingly, femtosecond-transient absorption spectroscopy showed that the two heteroleptic, cyclometalated complexes of this series did not inject holes into NiO, but their excited states were nevertheless quenched in a rapid process (on the time scale of hundreds of picoseconds). An identical result was obtained for the dyes on nonreactive ZrO2and we therefore attribute the short MLCT lifetime to self-quenching, due the high surface concentrations of the dyes. We further show that self-quenching on this time scale can potentially compete with hole injection also for functional NiO sensitizers. A ruthenium polypyridine complex, which has previously been used for NiO-based solar cells, was shown to inject holes only very slowly (τ ≈ 5 ns), in contrast to the common notion that hole injection in dye-NiO systems is ultrafast (predominantly subpicosecond time scale). The hole injection yield was estimated to only ca. 20%, which matches the reported APCE value of the corresponding device [Freys, J. C.; Gardner, J. M.; D’Amario, L.; Brown, A. M.; Hammarström, L.Dalton Trans.2012, 41, 13105]. Therefore, we suggest that slow injection and self-quenching might be a reason for the low photovoltaic performance of some p-type dye-sensitized solar cells.

In the present study of proton-coupled electron transfer (PCET) reactions, the excited-state of a fac-[(CO)3ReI(bpy)(4,4′-bpy)]+(bpy = 2,2′-bipyridine and 4,4′-bpy = 4,4′-bipyridine) complex was reductively quenched by a series of phenols. A variation of substituents on the phenols substantially alters their pKaand E° values and provides an opportunity to study photoinduced PCET as a function of their redox properties. Analyses of absorption spectral changes indicate that the phenols form a weak hydrogen bond with the pyridinic nitrogen of the 4,4′-bpy ligand in the ground-state, and ground-state association constant (KA) values were determined. This H-bonded adduct quenches the excited Re complex by PCET from the phenol, to form the reduced and protonated Re complex. The KAvalues obtained aid quantitative evaluation of the rate constant for the PCET reaction in the H-bonded adduct. Thus, photophysical studies and mechanistic analysis indicate that the reaction occurs via a concerted mechanistic pathway, for the unsubstituted phenol and phenols with electron-withdrawing substituents. Furthermore, the magnitude of the quenching varies systematically with the proton-coupled potentials of the phenols and not their hydrogen-bonding strength (as reflected in KA). This study is one of the first detailed analyses of intermolecular H-bonding between a self-assembling metal complex and a series of substituted phenols in an effort to study their relationship with the kinetic parameters in a photoinduced CPET reaction.

The magnetic field is a promising external stimulus for controlled and targeted delivery of therapeutic agents. Here, we focused on the preparation of a novel magnetically active polymeric micelle (MAPM) for magnetically targeted controlled drug delivery. To accomplish this, a number of superparamagnetic as well as biocompatible hybrid micelles were prepared by grafting four armed pentaerythretol poly(ε-caprolactone) (PE–PCL) onto the surface of Fe3O4magnetic nanoparticles (MNPs) of two different ranges of size (∼5 nm and ∼15 nm). PE–PCL (four-armed) was synthesized by ring-opening polymerization, and it has been subsequently grafted onto the surface of modified MNP through urethane (−NHCO−) linkage. Polymer-immobilized MNP (5 and 15 nm) showed peculiar dispersion behavior. One displayed uniform dispersion of MNP (5 nm), while the other (15 nm) revealed associated structure. This type of size dependent contradictory dispersion behavior was realized by taking the van der Waals force as well as magnetic dipole–dipole force into consideration. The uniformly dispersed polymer immobilized MNP (5 nm) was used for the preparation of MAPM. The hydrodynamic size and bulk morphology of MAPM were studied by dynamic light scattering and high-resolution transmission electron microscopy. The anticancer drug (DOX) was encapsulated into the MAPM. The magnetic field triggers cell uptake of MAPM micelles preferentially toward targeted cells compare to untargeted ones. The cell viabilities of MAMP, DOX-encapsulated MAPM, and free DOX were studied against HeLa cell by MTT assay. In vitrorelease profile displayed about 51.5% release of DOX from MAPM (just after 1 h) under the influence of high frequency alternating magnetic field (HFAMF; prepared in-house device). The DOX release rate has also been tailored by on-demand application of HFAMF.

The diruthenium(III) compound [(μ‐oxa){Ru(acac)2}2] [1, oxa2−=oxamidato(2−), acac−=2,4‐pentanedionato] exhibits an S=1 ground state with antiferromagnetic spin‐spin coupling (J=−40 cm−1). The molecular structure in the crystal of 1⋅2 C7H8revealed an intramolecular metal–metal distance of 5.433 Å and a notable asymmetry within the bridging ligand. Cyclic voltammetry and spectroelectrochemistry (EPR, UV/Vis/NIR) of the two‐step reduction and of the two‐step oxidation (irreversible second step) produced monocation and monoanion intermediates (Kc=105.9) with broad NIR absorption bands (εca. 2000 M−1cm−1) and maxima at 1800 (1−) and 1500 nm (1+). TD‐DFT calculations support a RuIIIRuIIformulation for 1−with a doublet ground state. The 1+ion (RuIVRuIII) was calculated with an S=3/2 ground state and the doublet state higher in energy (ΔE=694.6 cm−1). The Mulliken spin density calculations showed little participation of the ligand bridge in the spin accommodation for all paramagnetic species [(μ‐oxa){Ru(acac)2}2]n, n=+1, 0, −1, and, accordingly, the NIR absorptions were identified as metal‐to‐metal (intervalence) charge transfers. Whereas only one such NIR band was observed for the RuIIIRuII(4d5/4d6) system 1−, the RuIVRuIII(4d4/4d5) form 1+exhibited extended absorbance over the UV/Vis/NIR range.

Ruthenium nitrosyl complexes have been isolated in the {RuNO}6and {RuNO}7configurations, employing the following reaction pathway for [RutrpybikX]n+: X = Cl–, [1]ClO4 → X = CH3CN, [2]ClO42→ X = NO2–, [3]ClO4 → X = NO+, [4]ClO43→ X = NO·, [4]ClO42. The singlecrystal Xray structures of [1]ClO4·C6H6·H2O, [2]ClO42·H2O, and [3]ClO4·H2O have been determined. The successive NO+NO·reversible and NO·NO–irreversible reduction processes of [4]3+appear at +0.36 and –0.40 V vs. SCE, respectively. While the νC=O frequency of the bik ligand at about 1630 cm–1is largely invariant on complexation and reduction, the νNO frequency for the {RuNO}6state in [4]3+at 1950 cm–1shifts to about 1640 cm–1on oneelectron reduction to the {RuNO}7form in [4]2+, reflecting the predominant NO+→ NO·character of this electron transfer. However, a sizeable contribution from ruthenium with its high spinorbit coupling constant to the singly occupied molecular orbital SOMO is apparent from the enhanced ganisotropy in the EPR spectrum [4]2+g1= 2.015, g2= 1.995, g3= 1.881; gav= 1.965; Δg= 0.134. The {RuNO}6unit in [4]3+reacts with OH–via an associatively activated process ΔS= –126.5 ± 2 J K–1 mol–1 with a secondorder rate constant of k= 3.3 × 10–2M–1 s–1, leading to the corresponding nitro complex [3]+. On exposure to light both {RuNO}6and {RuNO}7in [4]3+and [4]2+undergo Ru–NO photocleavage in CH3CN via the formation of [RutrpybikCH3CN]2+, [2]2+. The rate of photocleavage of the RuII–NO+bond in [4]3+kNO, 8.57 ×10–1s–1, t12= 0.80 s is found to be much faster than that of the RuII–NO·bond in [4]2+, [kNO·, 5.45 × 10–4s–1, t12= 21.2 min = 1272 s]. The photoreleased nitrosyl can be trapped as an MbNO adduct.© WileyVCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009

The quinonoid ligand‐bridged diruthenium compounds [(acac)2Ru(μ‐L2−)Ru(acac)2] (acac−=acetylacetonato=2,4‐pentanedionato; L2−=2,5‐dioxido‐1,4‐benzoquinone, 1; 3,6‐dichloro‐2,5‐dioxido‐1,4‐benzoquinone, 2; 5,8‐dioxido‐1,4‐naphthoquinone, 3; 2,3‐dichloro‐5,8‐dioxido‐1,4‐naphthoquinone, 4; 1,5‐dioxido‐9,10‐anthraquinone, 5; and 1,5‐diimido‐9,10‐anthraquinone, 6) were prepared and characterized analytically. The crystal structure analysis of 5in the racconfiguration reveals two tris(2,4‐pentanedionato)ruthenium moieties with an extended anthracenedione‐derived bis(ketoenolate) π‐conjugated bridging ligand. The weakly antiferromagnetically coupled {RuIII(μ‐L2−)RuIII} configuration in 1–6exhibits complicated overall magnetic and EPR responses. The simultaneous presence of highly redox‐active quinonoid‐bridging ligands and of two ruthenium centers capable of adopting the oxidation states +2, +3, and +4 creates a large variety of possible oxidation state combinations. Accordingly, the complexes 1–6exhibit two reversible one‐electron oxidation steps and at least two reversible reduction processes. Shifts to positive potentials were observed on introduction of Cl substituents (1→2, 3→4) or through replacement of NH by O (6→5). The ligand‐to‐metal charge transfer (LMCT) absorptions in the visible region of the neutral molecules become more intense and shifted to lower energies on stepwise reduction with two electrons. On oxidation, the para‐substituted systems 1–4exhibit monocation intermediates with intervalence charge transfer (IVCT) transitions of RuIIIRuIVmixed‐valent species. In contrast, the differently substituted systems 5and 6show no such near infrared (NIR) absorption. While the first reduction steps are thus assigned to largely ligand‐centered processes, the oxidation appears to involve metal–ligand delocalized molecular orbitals with variable degrees of mixing.

Nitrosylruthenium derivatives having NO+ and NO· states have been synthesized in a stepwise manner starting from [RuII(trpy)(pdt)(Cl)](ClO4) {[1](ClO4)} → [RuII(trpy)(pdt)(CH3CN)](ClO4)2 {[2](ClO4)2} → [RuII(trpy)(pdt)(NO2)](ClO4) {[3](ClO4)} → [RuII(trpy)(pdt)(NO+)](ClO4)3 {[4](ClO4)3} → [RuII(trpy)(pdt)(NO·)](ClO4)2 {[4](ClO4)2} [trpy = 2,2′:6′,2″-terpyridine, pdt = 5,6-diphenyl-3-pyridyl-as-triazine]. The molecular identity of [1](ClO4) and [2](ClO4)2 and the subsequent stereoretentive transformation of [1](ClO4) → [2](ClO4)2 have been authenticated by single-crystal X-ray structures. Electrochemical and spectral features are investigated as a function of the monodentate ligands (Cl–, CH3CN, NO2–, NO+, NO·). The kinetic and thermodynamic aspects of the reaction of the moderately strong electrophilic {RuII–NO+} center [ν(NO): 1944 cm–1] in [4]3+ with a nucleophile such as OH– have been studied. The nitrosyl species [RuII(trpy)(pdt)(NO+)]3+ ([4]3+) can be selectively reduced to [RuII(trpy)(pdt)(NO·)]2+ ([4]2+) electrochemically as well as chemically by hydrazine hydrate. On exposure to light an acetonitrile solution of [RuII(trpy)(pdt)(NO·)]2+ ([4]2+) undergoes slow photocleavage of the RuII–NO bond over a period of 4 h, resulting in the corresponding solvated species [RuII(trpy)(pdt)(CH3CN)]2+ ([2]2+). The rate of photolability of the RuII–NO bond in [4]2+ has been monitored spectrophotometrically. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Valence-state distributions in the ruthenium quinonoid (L) frameworks of [Ru(trpy)(Cl)(L1)]ClO4 (1-ClO4) and [Ru(trpy)(Cl)(L2)]ClO4 (2-ClO4) (L1 = o-iminobenzoquinone, L2 = o-diiminobenzoquinone, and trpy = 2,2′:6′,2″-terpyridine) have been examined by structural, spectroelectrochemical, and density functional studies. The structural data, in corroboration with the DFT-calculated bond lengths, suggest that the primary valence formulation of 1+ and 2+ is a spin-coupled singlet configuration of [RuIII(trpy)(Cl)(LSq)]+ with a minority contribution from diamagnetic [RuII(trpy)(Cl)(LQ)]+. Consequently, the closely spaced successive two oxidation processes of 1+ and 2+ can be assigned to RuIII→RuIV and LSq→LQ, which involve the HOMO and HOMO–3 levels, respectively. The one-electron-oxidized species 12+ and 22+ display sharp EPR signals with g values of 2.011 and 2.014 at 77 K, respectively. The free radical EPR signal (g ≈ 2.0) of the one-electron-reduced species 1 or 2 signifies the preferential involvement of the ruthenium-based orbitals in the first reduction process to yield [RuII(trpy)(Cl)(LSq)], although the LUMO is calculated to be a mixture of dπ(Ru) (≈24 %) and π*(L) (≈ 70 %). The subsequent second (1–/2–) and third (12–/22–) reduction steps in each case are associated simply with the terpyridyl-based orbitals (≥90 %). The lowest energy charge-transfer transitions of 1+ and 2+ at 556 and 509 nm are predicted to be HOMO → LUMO+1 and HOMO–1 → LUMO+1 transitions, respectively. In the successive oxidations 1+/2+ → 12+/22+ → 13+/23+ the lowest energy charge-transfer transitions undergo a blue shift with a substantial reduction in intensity. The lowest energy charge-transfer transitions, however, are red shifted with a reduction in intensity on going from (1+/2+) to 1/2. The origin of the transitions in the 12+/22+ and 1/2 systems is predicted by TDDFT analysis. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

The new compounds [(acac)2Ru(μ‐boptz)Ru(acac)2] (1), [(bpy)2Ru(μ‐boptz)Ru(bpy)2](ClO4)2(2‐(ClO4)2), and [(pap)2Ru(μ‐boptz)Ru(pap)2](ClO4)2(3‐(ClO4)2) were obtained from 3,6‐bis(2‐hydroxyphenyl)‐1,2,4,5‐tetrazine (H2boptz), the crystal structure analysis of which is reported. Compound 1contains two antiferromagnetically coupled (J=−36.7 cm−1) RuIIIcenters. We have investigated the role of both the donor and acceptor functions containing the boptz2−bridging ligand in combination with the electronically different ancillary ligands (donating acac−, moderately π‐accepting bpy, and strongly π‐accepting pap; acac=acetylacetonate, bpy=2,2′‐bipyridine pap=2‐phenylazopyridine) by using cyclic voltammetry, spectroelectrochemistry and electron paramagnetic resonance (EPR) spectroscopy for several in situ accessible redox states. We found that metal–ligand–metal oxidation state combinations remain invariant to ancillary ligand change in some instances; however, three isoelectronic paramagnetic cores Ru(μ‐boptz)Ru showed remarkable differences. The excellent tolerance of the bpy co‐ligand for both RuIIIand RuIIis demonstrated by the adoption of the mixed‐valent form in [L2Ru(μ‐boptz)RuL2]3+, L=bpy, whereas the corresponding system with pap stabilizes the RuIIstates to yield a phenoxyl radical ligand and the compound with L=acac−contains two RuIIIcenters connected by a tetrazine radical‐anion bridge.

With the development of the internet and the availability of smart phones, online shopping and the number of digital buyers have increased enormously under the present social context (COVID-19). The major pitfall of this marketing system is the random non-availability of/refusal by customers. Nowadays, with the development of infrastructure, there are several route connections among the different locations worldwide. Considering these, we formulate some multi-path routing for goods delivery with refusal problems (MPRfGDwRPs) against online booking having different route connections between nodes (customers) and solved by a novel Type-2 fuzzy logic based fireworks algorithm (T2FLFWA) developed for discrete problems with probability-based selection and generation based prime mutation. In T2FLFWA, inferences are drawn to obtain the amplitude coefficient against the assumed spark number and iteration ratio. Some instances from TSPLIB are solved and supremacy of T2FLFWA is established through ANOVA test. In MPRfGDwRP, a delivery man starts with goods from a warehouse against customers’ online demands under cash-on-delivery or cash-on bookings systems and delivers the appropriate goods to the respective customers located at different locations. The random refusal or non-availability of customers is considered. The optimum travel plan and appropriate routes between the nodes are selected for minimum total cost. The models are illustrated numerically through a real-life problem. Some managerial conclusions are drawn. The novelty of the investigation is that for the first time, T2FLFWA for discrete problems is developed, delivery man’s routing plan with multiple paths between nodes with refusals is formulated and its solution using T2FLFWA is presented.