Photocatalytic activity of a novel Bi-based oxychloride catalyst Na0.5Bi1.5O2Cl

A Bi-based oxychloride Na_0.5Bi_1.5O₂Cl with a layered structure as a novel efficient photocatalyst was studied in the present paper. The powder was synthesized by a solid state reaction method. It was characterized by X-ray diffraction, scanning electron microscope and UV–vis diffuse reflectance spectrum. Degradation of methyl orange was used to evaluate the photocatalytic activity. The as-synthesized Na_0.5Bi_1.5O₂Cl has a smaller optical band gap of 3.04 eV than BiOCl (E_g = 3.44 eV). It possesses a fair visible-light-response ability. The UV-induced photocatalytic activity follows the decreasing order of BiOCl > Na_0.5Bi_1.5O₂Cl > TiO₂, different from the order of Na_0.5Bi_1.5O₂Cl > TiO₂ > BiOCl under visible light irradiation. The dispersion of Pt over Na_0.5Bi_1.5O₂Cl leads to an obvious increase in the photocatalytic performance. The internal electric fields between [Na_0.5Bi_1.5O₂] and [Cl] slabs favor the efficient separation of photostimulated electron–hole pairs.     

Vibrational interactions in dimethylgold(III) halides and carboxylates

The far-infrared and Raman spectra of binuclear molecules [Me₂AuX]₂ (X = Cl, Br, I) and [Me₂Au(OOCR)]₂ (R = Me, CF₃, Bu^t, Ph) in the 600–70 cm⁻¹ region are reported. The experimentally measured vibrational frequencies of [Me₂AuX]₂ are in a good agreement with density functional theory predictions. The Au…Au vibrational interactions predicted to be in the 270–60 cm⁻¹ region of [Me₂AuX]₂ far-IR and Raman spectra have been observed. The Raman-active Au…Au vibrations of the [Me₂Au(OOCR)]₂ molecules were found to be in the same region as those of [Me₂AuX]₂. The Au–X stretching modes were observed between 100 and 250 cm⁻¹ in accordance with the DFT predictions. Their frequencies in the IR spectra of [Me₂AuX]₂ increase in the sequence I < Br < Cl while the AuC₂ stretching frequencies decrease in the same order. This fact might be an evidence of the decreasing covalent character of the gold-halogen bridges. The Au–O stretching bands of dimethylgold(III) carboxylates have been observed in the 500–250 cm⁻¹ region, and Au–C stretching frequencies of both [Me₂AuX]₂ and [Me₂Au(OOCR)]₂ compounds have been found between 600 and 500 cm⁻¹.     

Effect of ionic liquid 1-methylimidazolium chloride on the vapour liquid equilibrium of water,methanol, ethanol,and {water + ethanol} mixture

Measurements of vapour pressure data were conducted using a quasi-static ebulliometer for systems containing water, methanol, ethanol, and a mixture of {water + ethanol} in the presence of an ionic liquid (IL), namely, 1-methylimidazolium chloride ([MIm]Cl), wherein the IL-content ranged from w₂ = (0.10 to 0.50). The vapour pressure data of IL-containing binary systems were correlated by the NRTL model with an overall average absolute relative deviation (AARD) of 0.0103, and the resulting binary parameters were used to predict the vapour pressures of a ternary system {water + ethanol + [MIm]Cl} with an AARD less than 0.0077. Further, the isobaric vapour liquid equilibria (VLE) for the ternary system {water + ethanol + IL} with IL-content of w₃ = (0.10, 0.30, and 0.50) for [MIm]Cl and x₃ = 0.15 for [MIm]Cl, [C₄MIm]Cl, and [C₆MIm]Cl were predicted at 101.3 kPa, respectively. It is indicated that [MIm]Cl presents the strongest ability to enhance the relative volatility of ethanol to water in the mixture of {water + ethanol} than that of [C₄MIm]Cl and [C₆MIm]Cl, which is consistent with the cationic sizes and hence the ionic hydration ability. Therefore, distillation separation of the azeotrope of {water + ethanol} can be sufficiently facilitated by the addition of [MIm]Cl at a specified content.     

Second-order non-linear optical response in LB films for the metal complexes

The complexes with long alkyl chains {[Fe(C₁₆-trz)₃](ClO₄)₂}_n (1), [Fe(C₁₅-BPT)₂(NCS)₂] (2), [Fe(C₁₆-salen)Cl] (3), [Fe(C₁₆-salmmen)Cl] (4), K[Fe(C₁₆-salen)(CN)₂] (5), K[Fe(C₁₆-salmmen)(CN)₂] (6), Na[Fe(C₁₆-salmmen)(CN)₂] (7), [Mn(C₁₆-salen)Cl] (8), [Ni(C₁₆-salen)] (9), [Cu(C₁₆-salen)] (10) were synthesized (C₁₆-trz = 4-hexadecyl-1,2,4-triazole, C₁₅-BPT = N-(3,5-di-2-pyridinyl-4H-1,2,4-triazol-4-yl)-hexadecanecarboxamide, C₁₆-salen = N,N-bis[4-(hexadecyloxy)salicylidene]ethylenediamine, C₁₆-salmmen = N,N′-bis[4-(hexadecyloxy)salicylidene]-1,2-diaminopropane). Langmuir–Blodgett (LB) films of compounds 1–10 were prepared (Scheme 1). The transfers of the molecules from onto the gas–water surface to glass substrate were confirmed by UV–Vis spectra. The second harmonic generation (SHG) were estimated for the LB films formed by the metal complexes. The SHG was observed for the complexes with the long alkyl chains in LB film. The order of the intensity for the SHG related with the number of unpaired d electrons or the d electron configurations.     

Mesoporous cadmium bismuth niobate (CdBi_2Nb_2O_9) nanospheres for hydrogen generation under visible light

Herein, we report visible light active mesoporous cadmium bismuth niobate(CBN) nanospheres as a photocatalyst for hydrogen(H_2) generation from copious hydrogen sulfide(H_2S). CBN has been synthesized by solid state reaction(SSR) and also using combustion method(CM) at relatively lower temperatures.The as-synthesized materials were characterized using different techniques. X-ray diffraction analysis shows the formation of single phase orthorhombic CBN. Field emission scanning electron microscopy and high resolution-transmission electron microscopy showed the particle size in the range of ~0.5–1 μm for CBN obtained by SSR and 50–70 nm size nanospheres using CM, respectively. Interestingly, nanospheres of size 50–70 nm self assembled with 5–7 nm nanoparticles were observed in case of CBN prepared by CM.The optical properties were studied using UV–visible diffuse reflectance spectroscopy and showed band gap around ~3.0 eV for SSR and 3.1 eV for CM. The slight shift in band gap of CM is due to nanocrystalline nature of material. Considering the band gap in visible region, the photocatalytic activity of CBN for hydrogen production from H_2S has been performed under visible light. CBN prepared by CM has shown utmost hydrogen evolution i.e. 6912 μmol/h/0.5 g which is much higher than CBN prepared using SSR.The enhanced photocatalytic property can be attributed to the smaller particle size, crystalline nature,high surface area and mesoporous structure of CBN prepared by combustion method. The catalyst was found to be stable, active and can be utilized for water splitting.     

Thermodynamic studies of the ionic liquid 1-hexyl-3-methylimidazolium chloride [C6mim][Cl] in polyethylene glycol aqueous solutions

Vapour pressure osmometery (VPO) measurements at T = 308.15 K for {[C₆mim][Cl] + water}, {[C₆mim][Cl] + (0.005, 0.0155, and 0.0263) mol · kg⁻¹ PEG2000 + water} and {[C₆mim][Cl] + (0.0017, 0.0052, and 0.0088) mol · kg⁻¹ PEG6000 + water} systems and isopiestic measurements at T = 298.15 K for {[C₆mim][Cl] + PEG2000 + water} and {[C₆mim][Cl] + PEG6000 + water} systems have been carried out. The VPO measurements were carried out at very low concentrations of PEG and from which the values of the water activities, osmotic coefficients, vapour pressure and activity coefficients were obtained. The data obtained from the VPO method show that over the whole concentration range of the ionic liquid (IL), the activity coefficients of [C₆mim][Cl] in the presence of PEG2000 are increased. Although, at high IL concentrations, the values of the activity coefficient of [C₆mim][Cl] in the presence of PEG6000 are also increased, however for low concentrations of IL the values of the activity coefficient of [C₆mim][Cl] in pure water are larger than those in aqueous PEG6000 solutions. For a known IL concentration, the values of water activity coefficient for the binary {[C₆mim][Cl] + water} system are larger than those for the ternary {[C₆mim][Cl] + PEG + water} systems and decrease by increasing the concentration of PEG or decreasing the molar mass of PEG. The constant water activity lines of the all ternary systems obtained from the isopiestic method show positive deviation from the linear isopiestic relation (Zdanovskii–Stokes–Robinson rule) derived using the semi-ideal hydration model. The results have been interpreted in terms of the solute–water and solute–solute interactions.     

Controlled synthesis of novel PbBiO<Subscript>2</Subscript>I microsphere structure towards photocatalytic degradation of bisphenol A

Novel visible-light-driven PbBiO₂I materials have been successfully synthesized through a one-pot ethylene glycol assisted solvothermal process in the presence of 1-hexyl-3-methylimidazolium iodide ([Hmim]I). The morphologies, compositions and properties of the PbBiO₂I materials were investigated by XRD, XPS, SEM, TEM, DRS and nitrogen adsorption–desorption isotherms. The results of SEM and TEM indicated that the as-prepared PbBiO₂I samples were microspheres with a diameter of about 1.5 μm assembled by nanosheets. The photocatalytic performance of the prepared PbBiO₂I materials was determined by colorless endocrine disrupting chemical bisphenol A (BPA) and antibiotic ciprofloxacin (CIP). PbBiO₂I materials have a very good visible light response with band gap of 1.98 eV, thus result in better photocatalytic degradation activity. Under the visible light irradiation for 3 h, about 72.5% of the BPA could be removed by PbBiO₂I microspheres. The main active species during the photodegradation process were determined to be superoxide radicals and holes.     

Mononuclear ruthenium(III) complexes containing chelating thiosemicarbazones: Synthesis,characterization and catalytic property

Mononuclear ruthenium(III) complexes of the type [RuX(EPh₃)₂(L)] (E = P or As; X = Cl or Br; L = dibasic terdentate dehydroacetic acid thiosemicarbazones) have been synthesized from the reaction of thiosemicarbazone ligands with ruthenium(III) precursors, [RuX₃(EPh₃)₃] (where E = P, X = Cl; E = As, X = Cl or Br) and [RuBr₃(PPh₃)₂(CH₃OH)] in benzene. The compositions of the complexes have been established by elemental analysis, magnetic susceptibility measurement, FT-IR, UV–vis and EPR spectral data. These complexes are paramagnetic and show intense d–d and charge transfer transitions in dichloromethane. The complexes show rhombic EPR spectra at LNT which are typical of low-spin distorted octahedral ruthenium(III) species. All the complexes are redox active and display an irreversible metal centered redox processes. Complex [RuCl(PPh₃)₂(DHA–PTSC)] (5) was used as catalyst for transfer hydrogenation of ketones in the presence of isopropanol/KOH and was found to be the active species.     

Mono- and di-nuclear oxorhenium(V) complexes of 4,7-diphenyl-1,10-phenanthroline

The reactions of [ReOX₃(AsPh₃)₂] (X = Cl, Br) with 4,7-diphenyl-1,10-phenanthroline (dpphen) have been examined and the complexes [ReO(OMe)X₂(dpphen)] and [Re₂O₃X₄(dpphen)₂]·2/3CH₂Cl₂ (X = Cl, Br) have been obtained. They were characterized by IR, UV–Vis spectroscopy, and single crystal X-ray analysis has been performed for [ReO(OMe)Cl₂(dpphen)] and [Re₂O₃Br₄(dpphen)₂]·2/3CH₂Cl₂. The nature of the frontier orbitals of [ReO(OMe)Cl₂(dpphen)] and [Re₂O₃Br₄(dpphen)₂] and the electronic transitions involved in the absorption spectra have been studied by means of the density functional and time-dependent density functional methods.     

Synthesis,characterization and photocatalytic performance of W,N, S-tri-doped TiO2 under visible light irradiation

W–S–N-tri-doped TiO₂ photocatalysts (WSNTiO₂) were prepared by a simple sol–gel method. Tungstic acid, sodium sulfate and urea were used as tungsten, sulfur and nitrogen sources, respectively. The morphology and microstructure characteristics of the photocatalysts were evidenced by means of XRD, BET, TEM, SEM and UV–vis DRS techniques. The XRD results show that the main crystal phase of samples is anatase. It was also found that the tri-doping of TiO₂ increases its BET specific surface area from 95 to 121 m²·g⁻¹. Besides, it was shown that tri-doping narrows the band gap of TiO₂ effectively, which has greatly improved the photocatalytic activity in the visible light region. The photocatalytic activity of tri-doped TiO₂ powders was compared to that of bi-doped ones through the degradation of Congo Red (CR) under visible irradiation. Thus, the prepared 0.5% W–N–S–TiO₂ heat treated at 450 °C showed the best photocatalytic activity compared to the prepared pure TiO₂, Degussa P25, and co-doped samples (WNTiO₂ and WSTiO₂). In particular, a Congo Red degradation rate of approximately 99% was reached after only 35 min of visible light irradiation in the presence of 0.5% of WNSTiO₂. Total organic carbon (TOC) removal of CR was up to 72% and confirmed its significant mineralization in the presence of 0.5% of WNSTiO₂ photocatalyst.     

Photocatalytic activity of nitrogen and copper doped TiO2 nanoparticles prepared by microwave-assisted sol-gel process

Cu and N-doped TiO₂ photocatalysts were synthesized from titanium (IV) isopropoxide via a microwave-assisted sol-gel method. The synthesized materials were characterized by X-ray diffraction, UV-vis diffuse reflectance, photoluminescence (PL) spectroscopy, SEM, TEM, FT-IR, Raman spectroscopy, photocurrent measurement technique, and nitrogen adsorption–desorption isotherms. Raman spectra and XRD showed an anatase phase structure. The SEM and TEM images revealed the formation of an almost spheroid mono disperse TiO₂ with particle sizes in the range of 9-17 nm. Analysis of N₂ isotherm measurements showed that all investigated TiO₂ samples have mesoporous structures with high surface areas. The optical absorption edge for the doped TiO₂ was significantly shifted to the visible light region. The photocurrent and photocatalytic activity of pure and doped TiO₂ were evaluated with the degradation of methyl orange (MO) and methylene blue (MB) solution under both UV and visible light illumination. The doped TiO₂ nanoparticles exhibit higher catalytic activity under each of visible light and UV irradiation in contrast to pure TiO₂. The photocatalytic activity and photocurrent ability of TiO₂ have been enhanced by doping of the titania in the following order: (Cu, N) - codoped TiO₂ > N-doped TiO₂ > Cu-doped TiO₂ > TiO₂. COD result for (Cu, N)-codoped TiO₂ reveals ∼92% mineralization of the MO dye on six h of visible light irradiation.     

Doping level effect on visible-light irradiation W-doped TiO2–anatase photocatalysts for Congo red photodegradation

A series of W-modified TiO₂ (W–TiO₂) photocatalysts were synthesized by a simple sol–gel method. The new photocatalysts were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–vis-diffuse reflectance spectroscopy (DRS), and Brunauer, Emmett and Teller (BET) surface area analyzer. The photoactivity of the W–TiO₂ photocatalysts was evaluated by the photocatalytic oxidation of Congo red (CR) dye. It was found that the average size of the prepared photocatalysts is 10 nm. Moreover, they have high surface areas (∼ 216 m² g⁻¹) and their light-absorption extends to the visible region compared to pure TiO₂. The effects of W-loading and of the calcination temperature of the prepared photocatalysts on their photocatalytic activity were also studied. The obtained results show that the W_0.5–TiO₂ photocatalyst calcined at 350 °C is much highly photoactive than non-doped or highly doped TiO₂. The enhanced photocatalytic activity of the weakly doped TiO₂ may be attributed to the increase in the charge separation efficiency and the presence of surface acidity on the W_0.5–TiO₂ photocatalyst.     

Synthesis of 2-substituted benzofuran derivatives by the palladium-catalyzed intermolecular coupling of 2-fluoroallylic acetates with phenols

We investigated the intermolecular coupling reaction of 2-fluoroallylic acetates with simple phenols by the [Pd(C₃H₅)Cl]₂, DPPF, and KHMDS at 100 °C for 16 h, and succeeded in obtaining 2-substituted benzofuran derivatives in good to high yield through the C–F bond activation and intermolecular cyclization.     

(Vapour + liquid) equilibria,volumetric and compressibility behaviour of binary and ternary aqueous solutions of 1-hexyl-3-methylimidazolium chloride,methyl potassium malonate,and ethyl potassium malonate

(Vapour + liquid) equilibrium data (water activity, vapour pressure, osmotic coefficient, and activity coefficient) of binary aqueous solutions of 1-hexyl-3-methylimidazolium chloride ([C₆mim][Cl]), methyl potassium malonate, and ethyl potassium malonate and ternary {[C₆mim][Cl] + methyl potassium malonate} and {[C₆mim][Cl] + ethyl potassium malonate} aqueous solutions were obtained through the isopiestic method at T = 298.15 K. These results reveal that the ionic liquid behaves as surfactant-like and aggregates in aqueous solutions at molality about 0.4 mol · kg⁻¹. The constant water activity lines of all the ternary systems investigated show small negative deviations from the linear isopiestic relation (Zdanovskii–Stokes–Robinson rule) derived using the semi-ideal hydration model. The density and speed of sound measurements were carried out on solutions of methyl potassium malonate and ethyl potassium malonate in water and of [C₆mim][Cl] in aqueous solutions of 0.25 mol · kg⁻¹ methyl potassium malonate and ethyl potassium malonate at T = (288.15 to 308.15) K at atmospheric pressure. From the experimental density and speed of sound data, the values of the apparent molar volume, apparent molar isentropic compressibility and excess molar volume were evaluated and from which the infinite dilution apparent molar volume and infinite dilution apparent molar isentropic compressibility were calculated at each temperature. Although, there are no clear differences between the values of the apparent molar volume of [C₆mim][Cl] in pure water and in methyl potassium malonate or ethyl potassium malonate aqueous solutions, however, the results show a positive transfer isentropic compressibility of [C₆mim][Cl] from pure water to the methyl potassium malonate or ethyl potassium malonate aqueous solutions. The results have been interpreted in terms of the solute–water and solute–solute interactions.     

Preparation of anatase phase titanium dioxide film by non-aqueous electrodeposition

The electrodeposition–annealing route to fabricating thin film of the promising photocatalyst material anatase-titanium dioxide (anatase-TiO₂) has been studied. The sample was deposited with a solution of N,N-dimethylformamide containing titanium compound by controlled-potential technique. SEM image showed the annealed sample at 600 °C for 1 h under air provided a continuous film with a thickness of ca. 350 nm. In this sample, X-ray photoelectron spectrum corresponding to the Ti 2p peak assigned to a chemical bond of TiO₂ and X-ray diffraction peaks assigned to the anatase phase were observed, respectively. Electrochemical oxidation in sodium sulfate solution on this annealed film was enhanced in the presence of UV light radiation. These results confirm the successful synthesis of photocatalytic anatase-TiO₂ film by the electrodeposition and annealing process.     

Solar active nano-TiO2 for mineralization of Reactive Red 120 and Trypan Blue: 1st Nano Update

Nano-TiO₂ was synthesized by sol–gel method. The catalyst was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) images, transmission electron microscope (TEM), BET surface area measurement and DRS analysis. The formation of anatase phase nano-TiO₂ was confirmed by XRD measurements and its crystalline size is found to be 15.2 nm. SEM images depict the crystalline nature of prepared TiO₂. The BET surface area of prepared TiO₂ is found to be 86.5 m² g^?1 which is higher than that of commercially available TiO₂–P25. The photocatalytic activity of prepared anatase phase TiO₂ has been tested for the degradation of two azo dyes: Reactive Red 120 (RR 120) and Trypan Blue (TB) using solar light. The photocatalytic activity of nano-TiO₂ is higher than TiO₂–P25 under solar light. The mineralization of dyes has been confirmed by chemical oxygen demand (COD) measurements.     

Mesoporous TiO2−xAy (A = N,S) as a visible-light-response photocatalyst

Mesoporous TiO_2?xA_y (A = N, S) thin films were fabricated using thiourea as a doping resource by a combination of sol-gel and evaporation-induced self-assembly (EISA) processes. The results showed that thiourea could serve two functions of co-doping nitrogen and sulfur and changing the mesoporous structure of TiO₂ thin films. The resultant mesoporous TiO_2?xA_y (A = N, S) exhibited anatase framework with a high porosity and a narrow pore distribution. The formation of the O–Ti–N and O–Ti–S bonds in the mesoporous TiO_2?xA_y (A = N, S) were substantiated by the XPS spectra. A new bandgap in visible light region (520 nm) corresponding to 2.38 eV could be formed by the co-doping. After being illuminated for 3 h, methyl orange could be degraded nearly completely by the co-doped sample under both ultraviolet irradiation and visible light illumination. While pure mesoporous TiO₂ could only degrade 60% methyl orange under UV illumination and showed negligible photodegradation capability in the visible light range. Furthermore, the photo-induced hydrophilic activity of TiO₂ film was improved by the co-doping. The mesoporous microstructure and high visible light absorption could be attributed to their good photocatalytic acitivity and hydrophilicity.     

Helical chains of [MO5Cl] octahedra – Three compounds in the new family AEM2Te3O8Cl2 (AE = Ca,Sr and M = Co,Ni)

The compounds CaCo₂Te₃O₈Cl₂, SrCo₂Te₃O₈Cl₂ and SrNi₂Te₃O₈Cl₂ were synthesized via solid–gas reactions and investigated using single-crystal X-ray diffraction. While the compound CaCo₂Te₃O₈Cl₂ formed large enough single crystals to allow for a detailed structural analysis, crystals of the Sr-containing compounds yielded evidence that they are isostructural. CaCo₂Te₃O₈Cl₂ crystallizes in the monoclinic system, space group P2₁/c, a = 6.537(2) Å, b = 9.088(2) Å, c = 19.500(9) Å, β = 113.36(4)°, Z = 4. It exhibits [CoO₅Cl] helical chains along the [010] direction, connected by [CaO₈] polyhedra, [TeO₃E] tetrahedra and [TeO₄E] trigonal bipyramids (the lone pair of electrons on Te^IV is designated as E) to form a layer. The layers are held together only by weak van der Waals forces; the shortest interlayer distance is a Te?Cl contact of 3.432(4) Å.     

Functionalized N-heterocyclic carbene iridium complexes: Synthesis,structure and addition polymerization of norbornene

Picolyl, pyridine, and methyl functionalized N-heterocyclic carbene iridium complexes [Cp¹Ir(C^N)Cl]Cl (4, C^N = 3-Methyl-1-picolyimidazol-2-ylidene), [Cp¹Ir(C^N)Cl][Cp¹IrCl₃] (5), [Cp¹Ir(C-N)Cl]Cl (6, C-N = 3-Methyl-1-pyridylimidazol-2-ylidene) and [Cp¹Ir(L)Cl₂] (7, L = 1,3-dimethylimidazol-2-ylidene) have been synthesized by transmetallation from Ag(I) carbene species, and characterized by ¹H NMR, ¹³C NMR spectra and elemental analyses. The molecular structures of 5–7 have been confirmed by X-ray single-crystal analyses. The iridium carbene complexes 4 and 6 show moderate catalytic activities (3.03 × 10⁵ g PNB (mol Ir)^?1 h^?1 and 1.70 × 10⁶ g PNB (mol Ir)^?1 h^?1) for the addition polymerization of norbornene in the presence of methylaluminoxane (MAO) as co-catalyst. The produced polynorbornene have been characterized by IR, ¹H NMR and ¹³C NMR spectra, showing it follows the vinyl-addition-type of polymerization.     

Synthesis,physico-chemical and spectral investigations of novel homo-bimetallic mixed-ligand complexes: 57Fe Mössbauer parameters of [Fe2(imda)2(H2O)3Cl]

The newly prepared homo-bimetallic complexes [M₂(imda)₂(H₂O)₄], [M₂(imda)₂(Bipy)₂] (M = Co, Ni or Cu) and [Fe₂(imda)₂(H₂O)₃Cl] (H₂imda = iminodiacetic acid and Bipy = 2,2′-bipyridine) have been studied employing IR, FAB-mass, ¹H and ¹³C NMR, EPR and ligand field spectra, which indicated a high-spin state of metal ion with hexa-coordinate environment. ⁵⁷Fe Mössbauer data of the homo-bimetallic complex [Fe₂(imda)₂(H₂O)₃Cl] confirm a high-spin configuration with Fe (±3/2 → 1/2) nuclear transitions and the presence of Kramer's double degeneracy. At RT, the spin–spin interactions of the neighbouring nuclei (Fe³⁺–Fe³⁺ = S_5/2–S_5/2) are anti-ferromagnetically coupled. However, at LNT, the complex acquires a mixed-valent [Fe^III–Fe^II] composition corroborated from the X-band EPR data. CV studies indicated the presence of quasi-reversible redox Cu^II/I, Cu^II/III, Fe^III/II, Fe^III/I and Fe^II/I couples.