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Wide bandgap (WBG) semiconductors, such as silicon carbide (SiC) and gallium nitride (GaN), exhibit superior physical properties and demonstrate great potential for replacing conventional silicon (Si) semiconductors with WBG technology, pushing the boundaries of power devices to handle higher blocking voltages, switching frequencies, output power levels, and operating temperatures. However, tradeoffs in switching performance and converter efficiency when substituting GaN devices for Si and SiC counterparts are not well-defined, especially in a cascode configuration. Additional research with further detailed investigation and analysis is necessitated for medium-voltage GaN devices in power converter applications. Therefore, the aim of this research is to experimentally investigate the impact of emerging 650/900 V cascode GaN devices on bidirectional dc-dc converters that are suitable for energy storage and distributed renewable energy systems. Dynamic characteristics of Si, SiC, and cascode GaN power devices are examined through the double-pulse test (DPT) circuit at different gate resistance values, device currents, and DC bus voltages. Furthermore, the switching behavior and energy loss as well as the rate of voltage and current changes over the time are studied and analyzed at various operating conditions. A 500 W experimental converter prototype is implemented to validate the benefits of cascode GaN devices on the converter operation and performance. Comprehensive analysis of the power losses and efficiency improvements for Si-based, SiC-based, and GaN-based converters are performed and evaluated as the switching frequency, working temperature, and output power level are in-creased. The experimental results reveal significant improvements in switching performance and energy efficiency from the emerging cascode GaN devices in the bidirectional converters.

The aerial parts of Artemisia judaica L. (A. judaica) and Artemisia monosperma (Delile) (A. monosperma) were collected from wild plant populations located in the eastern desert of Egypt. The essent...

Five new eight-coordinated Nd(III) mononuclear complexes with the formulae [Nd(ntfa)3(EtOH)2] (1), [Nd(ntfa)3(phen)] (2), [Nd(ntfa)3(bipy)] (3), [Nd(ntfa)3(5,5′-Me2bipy)] (4) and [Nd(ntfa)3(4,4′-Mt2bipy)] (5), where ntfa = 4,4,4-trifluoro-1-(naphthalen-2-yl)butane-1,3-dionate, phen = phenanthroline, bipy = 2,2′-dipyridine, 5,5′-Me2bipy = 5,5′-dimethyl-2,2′-dipyridine, and 4,4′-Mt2bipy = 4,4′-dimethoxy-2,2′-dipyridine, were synthesized and structurally characterized. Magnetic measurements were carried out on complexes 2–5. Dynamic magnetic studies revealed single-molecule magnet (SMM) behavior for complexes 2, 4 and 5 with anisotropy energy barriers and preexponential factors of Ueff = 18 cm−1, τ0 = 2.2 × 10−7 s; Ueff = 31 cm−1, τ0 = 1.0 × 10−9 s and Ueff = 19 cm−1, τ0 = 8.7 × 10−8 s, respectively. The ancillary chelating bipyridyl ligands in complexes 2–5 greatly enhance the solid state luminescence emission in the visible and NIR regions through efficient energy transfer from the ligands to the central Nd3+ ion. This study highlights the bifunctionality of the Nd(III) complexes.

A series of heteroleptic copper(II) complexes of the composition [Cu(L1–5)Cl]X, where X = ClO4 and/or PF6 and [bis(2-ethyl-di(3,5-dimethyl-1H-pyrazol-1-yl))-(6-methyl-(2-pyridylmethyl))]amine (L1), [bis(2-ethyl-di(3,5-dimethyl-1H-pyrazol-1-yl))-(3,4-dimethoxy-(2-pyridylmethyl))]amine (L2), [bis(2-ethyl-di(3,5-dimethyl-1H-pyrazol-1-yl)-(2-quinolymethyl)]amine (L3), [bis(2-ethyl-di(3,5-dimethyl-1H-pyrazolyl)-(di(3,5-dimethyl-1H-pyrazol-1-yl-methyl))]amine (L4) and [bis(2-ethyl-di(3,5-dimethyl-1H-pyrazol-1-yl)-(5-methyl-3-phenyl-1H-pyrazol-1-yl-methyl)]amine (L5), were prepared and thoroughly characterized including single-crystal X-ray diffraction technique. The in vitro cytotoxicity of complexes against A2780, A2780R, HOS and MCF-7 human cancer cell lines was evaluated using the MTT test. The results revealed that complexes [Cu(L1)Cl]PF6 (1-PF6), [Cu(L2)Cl]ClO4 (2-ClO4) and [Cu(L3)Cl]PF6 (3-PF6) are the most effective, with IC50 values ranging from 1.4 to 6.3 μM, thus exceeding the cytotoxic potential of metallodrug cisplatin (IC50 values ranging from 29.9 to 82.0 μM). The complexes [Cu(L4)Cl]PF6 (4-PF6) and [Cu(L5)Cl]PF6 (5-PF6) showed only moderate cytotoxicity against A2780, with IC50 = 53.6 μM, and 33.8 μM, respectively. The cell cycle profile, time-resolved cellular uptake, interactions with small sulfur-containing biomolecules (cysteine and glutathione), intracellular ROS production, induction of apoptosis and activation of caspases 3/7 were also evaluated in the case of the selected complexes. It has been found that the best performing complexes 1 and 2 cause cell arrest in the G2/M phase and induce apoptosis via the increase in production of ROS, dominantly due to the overproduction of superoxide.

Abstract Six mixed metal complexes with 3-aminopyridine (3-ampy) as a co-ligand have been synthesized: catena-{[M(μ2-3-ampy)(H2O)4]SO4·H2O} (M=Ni (1) and Co (2)), [Co(3-ampy)4(NCS)2] (3), [Co(3-ampy)2(NCS)2] (4), [Co(3-ampy)4(N3)2] (5) and mer-[Co(3-ampy)3(N3)3] (6), (NCS−=isothiocyanate ion, N3− azide ion), and characterized by physio-chemical and spectroscopic methods as well as single crystal X-ray and powder diffraction. In the isostructural complexes 1 and 2 single μ2-3-ampy links the Ni(II) and Co(II) centers into polymeric chains. The mononuclear Co(II) and Co(III) pseudohalide complexes 3–6 reveal only terminal 3-ampy ligands. The 3-ampy ligands form supramolecular hydrogen bonded systems via their NH2-groups and non-covalent π-π ring-ring interactions via their pyridine moieties. Thermoanalytical properties were investigated for 1–3. Graphic abstract

Introduction Copper oxide nanoparticles (CuO-NPs) are widely used as feed additives for livestock and poultry and implicated in many biomedical applications; however, overload of copper NPs induces various toxicological changes and dysfunction of animal's organs. Thus, this study was designed to evaluate the comparative toxicological effects of biologically and chemically synthesized CuO-NPs on mice. Methods Transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR) were used to characterize the sizes, shapes and functional groups of CuO-NPs. Forty-five mice were randomly allocated into three groups. Control group received distilled water. The second group was administered a single dose of biologically synthesized CuO-NPs (500 mg/kg bw) orally. The third group was administered a single dose of chemically synthesized CuO-NPs (500 mg/kg bw) orally. Results TEM revealed that biologically synthesized NPs were spherical in shape, whereas chemically synthesized NPs were spherical or elongated in shape. XRD showed that the size of biologically synthesized NPs ranged from 4.14 to 12.82 nm and that of chemically synthesized NPs ranged from 4.06 to 26.82 nm. FT-IR spectroscopy indicated that the peaks appeared between 779 cm-1 and 425 cm-1 in biologically synthesized NPs and between 858 cm-1 and 524 cm-1 in chemically synthesized NPs were for Cu-O nanostructure. Four mice died due to administration of biologically synthesized CuO-NPs. Both biologically and chemically synthesized CuO-NPs induced leukocytosis, elevated serum activities of alanine aminotransferase and aspartate aminotransferase and serum levels of urea and creatinine and increased P53 mRNA and caspase-3 protein expressions in hepatic tissues. Moreover, CuO-NPs induced degenerative and necrotized changes in hepatic, renal and splenic tissues. Biochemical, apoptotic and pathological changes were more serious in mice administered with biologically synthesized CuO-NPs. Conclusion This study indicated that a high dose of biologically and chemically synthesized CuO-NPs induced adverse effects on hepatic, renal and splenic tissues. At the same dose level, the biologically synthesized CuO-NPs evoked more potent toxic effects than the chemically synthesized CuO-NPs.

The optimum choice of the ligand that stabilizes the colloidal quantum dots and passivate the surface is crucial for tuning the energy level and remain elusive. The atomic ligand passivation with iodide remains superior over other surface treatments. Herein, we applied the iodide ligand to passivate the CdSe nanocrystals with an excitonic absorption at 2.1 eV by a liquid-liquid extraction process. We took the view of the change in the optical and structural properties upon ligand exchange. Finally, we tested the performance of the iodide treated dots by employing it in an inverted structure polymer solar cell based on P3HT: PCBM.

Two penta-coordinate complexes of the general formula [Co(Ln)(NCS)]ClO4, where L1 = {bis[(3,5-dimethyl-1H-pyrazol-1-yl)ethyl]-[(3,4-dimethoxypyridin-2-yl)methyl]}amine and L2 = {bis[(3,5-dimethyl-1H-pyrazol-1-yl)ethyl]-[(4-methoxy-3,5-dimethylpyridin-2-yl)methyl]}amine, have been synthesized and thoroughly characterized. Each of the cobalt(ii) atoms is penta-coordinated in the {CoN5} donor set with a distorted square-pyramidal geometry in [Co(L1)(NCS)]ClO4·MeOH (1), while the vicinity of the central atom can be described as a distorted trigonal-bipyramidal geometry in [Co(L2)(NCS)]ClO4 (2) as revealed using the SHAPE analysis. Differences in interatomic parameters among the cobalt(ii) and donor atoms in 1 and 2 have definite impact on the magnetic features of both compounds. The complexes show an easy-axis magnetic anisotropy (D = -38.5 cm-1 for 1 and D = -8.5 for 2), and both complexes reveal a large rhombicity with E/D = 0.21 for 1 and E/D = 0.29 for 2. The ZFS parameters (g, D and E) were also calculated using CASSCF/NEVPT2 methods and they are in good agreement with those determined from experimental data. A frequency dependent out-of-phase susceptibility has been observed in external magnetic field (Bdc = 0.1 T) revealing the following parameters of slow relaxation of magnetization for 1: energy of the spin reversal barrier, Ueff = 16.0 cm-1 (Ueff/kB = 23.0 K) and the relaxation time, τ0 = 1.28 × 10-6 s. In the case of complex 2, no maxima of frequency dependent out-of-phase susceptibility have been observed and thus, the value of Ueff = 17 cm-1 has been estimated using the expression Ueff = |D| × (S2 - 1/4). It has been demonstrated that the degree of substitution and the type of substituents on the pyridyl moieties of the tripodal ligands (L1 and L2) used in these penta-coordinate cobalt(ii) complexes have significant impact on structural and magnetic features.

Synthesizing nanoparticles (NPs) capable of hindrance the microbial colonization is a global demand. Such NPs can prevent emerging infectious diseases that harm the public health. In this paper, a co-precipitation method is employed to synthesize colloidal of metal iodide, namely copper iodide (CuI), silver iodide (AgI), and lead iodide (PbI2). Subsequently, EDS, XRD, HRSEM with mapping technique are conducted to study the structural properties of the as-synthesized samples. Additionally, their absorption is highlighted using UV/Vis spectroscopy. NPs with average crystallite size equals to 54.98, 57.02, and 23.47 nm for PbI2, CuI, and AgI, respectively are calculated. SEM images show that PbI2 consists of randomly-oriented dense nanoflakes of iodide. CuI NPs have a dense medium with tiny particles adhered to larger particles related to copper. Further, AgI sample contains agglomerated crystallites with a combination of small and large sizes. Antimicrobial activity of the samples against all tested standard pathogens is examined. In particular, AgI NPs have a prominent antimicrobial capability against Escherichia coli, Candida albicans and Staphylococcus aureus (ZOI of 18.0, 16.0 and 15.0 mm, respectively). Therefore, the AgI NPs can be safely used in solving serious industrial, pharmaceutical and medical challenges and particularly in the treatment of surface infectious diseases.

In this paper, an optical modulator design based on a silicon-on-calcium fluoride platform with a layer of Vanadium dioxide (VO2) is proposed. The VO2 as a phase changing material is used to control the modulation process, making use of the phase transition of the VO2 material between dielectric and metallic states. The modal properties of the proposed optical modulator are studied and analyzed using the well-known full vectorial finite element method. Whereas, the light propagation is studied using the 3D finite difference time domain method. The suggested device offers a number of advantages such as low insertion loss of 0.431 dB/µm and high extinction ratio of 14.99 dB/µm at a wavelength of 3.95 µm and device length LD of 2 µm. To the best of the authors’ knowledge, this is the first time to present an infrared optical modulator based on silicon-on-calcium fluoride platform.

Six pseudohalide zinc(II) containing a variety of N-donor auxiliary amines were structurally characterized. These include two mononuclear trigonal bipyramidal [Zn(NTB)(N3)]ClO4·½H2O (3) and [Zn(TPA)(NCS)]ClO4 (4), two distorted octahedral [Zn(1,8-damnph)2(dca)2] (5) and [Zn(8-amq)2(dca)2] (6a) as well as two 1D polymeric chains catena-[Zn(isq)2(μ1,5-dca)2] (7) and catena-[Zn(N,N-Me2en)2(μ1,5-dca)]dca (8), where NTB = tris(2-benzimidazolylmethyl)amine, TPA = tris(2-pyridylmethyl)amine, 1,8-damnph = 1,8-diaminonaphthalene, 8-amq = 8-amino-quinoline, isq = isoquinoline (isq) and N,N-Me2en = N,N-dimethylethylenediamine. In general, with the exception of 6 and 8, the complexes exhibited luminescence emission in MeOH associated with red shift of the emission maxima, and the strongest visible fluorescence peak was detected at 421 nm (λex = 330 nm) in the case of Complex 5.

A highly sensitive 2D Si photonic crystal (PhC) sensor is proposed and analyzed for the detection of gamma-ray doses in the visible light region. The suggested PhC has a cavity infiltrated by poly-vinyl alcohol (PVA) polymer doped with crystal violet and carbol fuchsine dyes. The transmission through the proposed design has a peak at the resonance frequency, which is sensitive to the gamma-ray doses. The geometrical parameters of the suggested PhC are studied to maximize the sensor sensitivity, quality factor, and normalized transmission. The proposed sensor achieves high sensitivity of 150 nm per refractive index unit (nm/RIU) with high linearity and high-quality factor (Q) of 808. The analysis is carried out using full-vectorial finite-element method and the plane wave expansion method. To the best of the author's knowledge, it is the first time to use 2D-PhC technology for gamma-ray detection.

Membrane engineering is currently classified as an eco-friendly cleaning technology in various fields, especially for wastewater treatment, and its use is increasing due to the growing interest in ...

Two coordination polymers of mono-dimensional doubly bridged-azido-cobalt(II) complexes catena-[Co(2,6-lutidine-N-oxide)(μ1,1-N3)2] (1) and catena-{[Co(μ1,1-N3)2(H2O)2](3-picoline-N-oxide)2} (2), where 2,6-lutidine-N-oxide = 2,6-dimethylpyridine-N-oxide and 3-picoline-N-oxide = 3-methylpyridine-N-oxide, were synthesized, and structurally characterized by single crystal X-ray crystallography. The Co(II) cations in complexes 1 and 2 are penta- and hexa-coordinate, respectively with four μ1,1-bridging azido groups and a terminal 2,6-lutidine-N-oxide molecule in 1 or two trans aqua molecules in 2. Magnetic relaxations in the zero field are consistent with single chain magnetic behavior (SCM) and the ac susceptibility measurements revealed that the weak ferromagnetic exchanges in the two complexes are associated with slow relaxation of magnetization. Complex 2 exhibits metamagnetic transition with an antiferromagnetic phase transition at 12 K at the applied field of 200 Oe.

A new 4-styrylpyridine (4-spy)-based square planar copper(II) complex, [Cu(4-spy)2(NCS)2] {4-spy = 4-styrylpyridine} (1), has been synthesized and characterized by elemental analysis and single-crystal X-ray diffraction study. The complex crystallizes in triclinic space group Pī and forms square planar geometry. Complex 1 is self-assembled to construct 3D supramolecular architecture via π–π interactions. Complex 1 exhibits strong biomimetic phenoxazinone synthase-like activity under mild conditions for the aerial oxidation of o-aminophenol to amino phenoxazinone, i.e. modeling the catalytic function of the copper-containing enzyme phenoxazinone synthase. The turnover number (k cat) for the process in methanol is 50.13 × 10−2 s−1. The mechanism of phenoxazinone synthase-like activity has been proposed for the Cu(II) catalyst with the help of mass spectral analysis. Density functional theory study has also been explored to corroborate the experimental findings.

Five new metal(II) dicyanamido (dca) complexes with 3-aminopyridine (py-NH2) have been synthesized, catena-[M(μ1,5-dca)2(py-NH2)2] {M = Mn (1), Cu (2), Co (3), Zn (4) and Cd (5)}, and characterized by elemental analysis, IR, UV–Vis spectroscopy, single crystal X-ray and powder diffraction, respectively. The isostructural polymeric 1D complexes feature double µ1,5-bridging dicyanamide ligands and two terminal 3-aminopyridine ligands located in a trans-conformation around the distorted M(II) octahedra, which add extra stability through their involvements in the formation of 3D supramolecular hydrogen bonded systems and the constitution of non-covalent π–π ring-ring interactions along the chain direction. The magnetic properties of complexes 1–3 were studied at variable temperature over the range 2–300 K. Luminescence enhancements upon complexation of dca ligands was observed in 4 and 5.

A dimeric [Cu(μ-4-HOMP)(4-HOMP)(NCS)2]2 (1) and three discrete monomeric complexes [Ni(3-HOMP)2(NCS)2(H2O)2] (2), [Co(3-HOMP)3(N3)3]·H2O (3) and [Zn(4-HOMP)2(NCS)2] (4), (3-HOMP = 3-hydroxymethylpyridine, 4-HOMP = 4-hydroxymethylpyridine) have been isolated and structurally characterized by IR, UV–Vis spectroscopy, XRPD, single crystal X-ray crystallography and Hirshfeld surface analysis as well as thermogravimetric analyses for complexes 1, 2 and 4. In dimeric complex 1 each penta-coordinated Cu2+ center is bridged through N,O-4-HOMP ligands, whereas metal ions in 2 and 3 are located in distorted octahedral geometry with mer-configuration in the azido complex 3. Distorted tetrahedral geometry is observed around Zn2+ in complex 4. The variable temperature magnetic susceptibility measurements of 1 showed very weak antiferromagnetic interaction.

The complexes [Cu(TPA)Cl]ClO4·½H2O (1-ClO4), [Cu(6-MeTPA)Cl]ClO4/PF6 (2-ClO4/2-PF6), [Cu(6-Me2TPA)Cl]PF6 (3-PF6), [Cu(BPQA)Cl]ClO4/PF6 (4-ClO4/4-PF6), [Cu(BPQA)Cl]ClO4/PF6 (4-ClO4/4-PF6), [Cu(BQPA)Cl]ClO4/PF6 (5-ClO4/PF6), [Cu(L1)Cl]ClO4/PF6 (6-ClO4/6-PF6), [Cu(L2)Cl]ClO4 (7-ClO4) and [Cu(L3)Cl]ClO4 (8-ClO4) have been synthesized and structurally characterized by spectroscopic techniques and single X-ray crystallography. The in vitro cytotoxicity of the prepared Cu(II) complexes was evaluated against A2780 (ovarian), A2780R (cisplatin-resistant variant) and MCF7 (breast cancer) human cancer cell lines. Overall, the complexes revealed significant-to-moderate cytotoxicity, with the best results obtained for the complexes [Cu(BQPA)Cl]ClO4 (5-ClO4) and [Cu(BQPA)Cl]PF6 (5-PF6), showing IC50 values within the range of 4.7–10.8 μM. The ability of the most cytotoxic complexes to cleave DNA under different conditions and the mechanisms underlying this activity were assessed by means of agarose gel electrophoresis.

Iron metal–organic framework, MIL-100(Fe) was prepared by a hydrothermal method and used as a support to incorporate diethylenetriamine (DETA) for the study of CO2 adsorption and separation of CO2/N2. All synthesized adsorbents were characterized by PXRD, N2 adsorption–desorption isotherms, FT-IR, TGA, SEM, and elemental analysis. Structural characterization results have revealed that the structure of MIL-100(Fe) was not changed by the incorporation of diethylenetriamine. The CO2 adsorption capacities were 29 cm3 g−1 and 41 cm3 g−1 at 298 K, 1 bar for MIL-100(Fe) and DETA–MIL-100(Fe), respectively. Adsorption of CO2 on DETA–MIL-100(Fe) was higher than that on MIL-100(Fe). The enhancement was due to the presence of amine groups which could form ammonium carbamate by interaction with CO2. Similarly, the N2 adsorption capacities were 3 cm3 g−1 and 0.9 cm3 g−1 at 298 K, 1 bar for MIL-100(Fe) and DETA–MIL-100(Fe), respectively. The decrease in N2 adsorption capacity was due to the decrease in surface area. The selectivity of CO2/N2 on DETA–MIL-100(Fe) was four times higher than that on MIL-100(Fe). The heat of CO2 adsorption was 74.2 kJ mol−1 at low coverage of CO2 on DETA–MIL-100(Fe) and the CO2 adsorption capacity was constant in each adsorption cycle over the same adsorbent.

The synthesis and structural characterization of six dicyanamido-cadmium(II) complexes are reported: catena-[Cd(μ1,3-dca)(μ1,5-dca)(3-ampy)] (1), catena-[Cd3(μ1,3,5-dca)2(μ1,5-dca)4(pyNO)2(H2O)2] (2), catena-{Cd(H2O)2(μ1,5-dca)2](2,6-lut-NO)} (3), catena-[Cd(Me2en)(μ1,5-dca)2] (4), catena-[Cd(Me4en)(μ1,5-dca)2] (5), and [Cd(1,8-damnp)2(dca)2] (6), where dca = dicyanamide anion, 3-ampy = 3-aminopyridine, pyNO = pyridine-N-oxide, 2,6-lut-NO = 2,6-lutidine-N-oxide, Me2en = N,N-dimethyl-ethylenediamine, Me4en = N,N,N′,N′-tetramethyl-ethylenediamine, and 1,8-damnp = 1,8-diaminonaphthaline. The coordination polymers have different dimensionalities: 1 and 5 form 3D networks structures, 3 and 4 form polymeric 1D chains and 1DD double chains, respectively. Ribbons of three fused polymeric chains are observed in 2. In 6, the mononuclear complex units form a hydrogen-bonded supramolecular 3D network. In the coordination polymer compounds, the dca linkers display three bonding modes: the most common μ1,5-dca and the least popular μ1,3- and μ1,3,5-dca bonding. The luminescence emission and thermal properties of the complexes were investigated.

The characteristics of silicon nanowires (SiNWs) with surface roughness are reported and analyzed for solar cell (SC) applications. The SiNWs are fabricated using a metal-assisted chemical etching process. The effects of the etching time and reaction temperature on the surface roughness and the performance of the SiNWs are investigated. Further, the optical and electrical characteristics of the roughed NW SC are numerically studied and optimized using 3D finite difference time domain and finite element analysis, respectively. The numerically optimized SiNWs with surface roughness offer high optical ultimate efficiency (η) of 32.51% with an enhancement of 15.98% over the smoothed SiNW. This is due to the surface textures of the nanowires which produce multiple light scattering between the NWs’ walls. This will enhance the optical path length through the NW and enrich its light absorption. The doping level of the surface roughness of NWs with p-type/intrinsic/n-type (p-i-n) axial configurations is also simulated to compute the optoelectronic performance of the suggested design. The p-i-n axial doped design offers a power conversion efficiency of 14.92%, whereas the conventional NWs have a power conversion efficiency of 13.16%.

A novel series of mononuclear five-coordinated pseudohalido-Cu(II) complexes displaying distorted square bipyramidal: [Cu(L1)(NCS)2] (1), [Cu(L2)(NCS)2] (2) and [Cu(L3)(NCS)]ClO4 (5) as well as distorted trigonal bipyramidal: [Cu(isp3tren)(N3)]ClO4 (3), [Cu(isp3tren)(dca)]ClO4 (4) and [Cu(tedmpza)(dca)]ClO4&middot, 0.67H2O (6) geometries had been synthesized and structurally characterized using X-ray single crystal crystallography, elemental microanalysis, IR and UV-vis spectroscopy, and molar conductivity measurements. Different N-donor amine skeletons including tridentate: L1 = [(2-pyridyl)-2-ethyl)-(3,4-dimethoxy)-2-methylpyridyl]methylamine and L2 = [(2-pyridyl)-2-ethyl)-(3,5-dimethyl-4-methoxy)-2-methyl-pyridyl]methylamine, and tetradentate: L3 = bis(2-ethyl-di(3,5-dimethyl-1H-pyrazol-1-yl)-[2-(3,4-dimethoxy-pyridylmethyl)]amine, tedmpza = tris[(2-(3,5-dimethyl-1H-pyrazol-1-yl)ethyl]amine and isp3tren = tris[(2-isopropylamino)ethyl)]amine ligands were employed. Molecular structural parameters such as nature of coligand, its chelate ring size and steric environment incorporated into its skeleton, which lead to adopting one of the two limiting geometries in these complexes and other reported compounds are analyzed and correlated to their assigned geometries in solutions. Similar analysis were extended to other five-coordinated halido-Cu(II) complexes.

The present work reports the performance of three types of polyethersulfone (PES) membrane in the removal of highly polluting and toxic lead Pb2+ and cadmium Cd2+ ions from a single salt. This study investigated the effect of operating variables, including pH, types of PES membrane, and feed concentration, on the separation process. The transport parameters and mass transfer coefficient (k) of the membranes were estimated using the combined film theory-solution-diffusion (CFSD), combined film theory-Spiegler-Kedem (CFSK), and combined film theory-finely-porous (CFFP) membrane transport models. Various parameters were used to estimate the enrichment factors, concentration polarization modulus, and P&eacute, clet number. The pH values significantly affected the permeation flux of the Pb2+ solution but only had a slight effect on the Cd2+ solution. However, Cd2+ rejection was highly improved by increasing the pH value. The rejection of the PES membranes increased greatly as the heavy metal concentration rose, while the heavy metal concentration moderately affected the permeation flux. The maximum rejection of Pb2+ in a single-salt solution was 99%, 97.5%, and 98% for a feed solution containing 10 mg Pb/L at pH 6, 6.2, and 5.7, for PES1, PES2, and PES3, respectively. The maximum rejection of Cd2+ in single-salt solutions was 78%, 50.2%, and 44% for a feed solution containing 10 mg Cd/L at pH 6.5, 6.2, and 6.5, for PES1, PES2, and PES3, respectively. The analysis of the experimental data using the CFSD, CFSK, and CFFP models showed a good agreement between the theoretical and experimental results. The effective membrane thickness and active skin layer thickness were evaluated using the CFFP model, indicating that the P&eacute, clet number is important for determining the mechanism of separation by diffusion.

Polyvinyl chloride-graft-poly ethyl acrylate (DHPVC-g-PEA) novel membranes were prepared for highly saline water desalination using DCMD. Free radical graft copolymerization was used to prepare DHPVC-g-PEA by applying an ethyl acrylate (EA) onto a PVC polymer backbone. The influence of the grafting reaction time on the PVC grafting percentage and on the resulting copolymer's characteristics was measured. The DHPVC-g-PEA preparation was affirmed via Fourier-transform infrared (FTIR) and energy-dispersive X-ray (EDX). The use of EDX revealed a new peak associated with oxygen, while the increased carbon percentage confirmed that an ester group was present on the PVC backbone. The best reaction time for obtaining excellent DHPVC-g-PEA membrane properties for membrane distillation (MD) application was 1 h. The following membrane characteristics were investigated: atomic force microscopy (AFM), contact angle (CA), scanning electron microscopy (SEM), thickness and porosity as well as the pore size and how it was distributed. Grafting PVC by the 1-hr reaction time of the EA affected the morphology of the modified membranes and decreased the membrane thickness, whereas the mean and maximum pore size as well as the roughness and contact angle were improved. The DHPVC-g-PEA membrane's upper surface had a very porous structure. The pure water permeate flux of the DHPVC-g-PEA membrane was enhanced by approximately twelvefold. When operated under the specified conditions (i.e., 35, 70, 100, and 200 g/L; 0.6 L/min; and 65 °C), the DCMD results for the DHPVC-g-PEA membrane demonstrated that its salt rejection was greater than 99.9%, with a permeate conductivity below 27 μS/cm.

Three cobalt(II) isothiocyanato complexes with 4-methoxypyridine (4-MOP) as a co-ligand have been synthesized: catena-[Co(4-MOP)2(μ1,3-NCS)2] (1), trans-[Co(4-MOP)4(NCS)2] (2), and [Co(4-MOP)2(NCS)2] (3) and structurally characterized by IR, UV–Vis spectroscopy and single crystal X-ray diffraction. The complexes 2 and 3 are discrete monomeric species with octahedral and tetrahedral geometries, respectively whereas the catena-[Co(4-MOP)2(μ1,3-NCS)2] (1) is featuring a polymeric 1D system with doubly bridging NCS− groups through the terminals N- and S-donor atoms in a trans octahedral geometry. The thermoanalytical behavior of 1–3 is reported. Magnetic susceptibility of the bridged-isothiocyanato coordination polymer 1 was studied down to a temperature of 2 K and at various magnetic dc and ac fields. These measurements indicate a metamagnetic transition in 1.

Metallic phthalocyanines (M-Pcs) have superior structure, electrical and optical properties. Therefore, M-Pcs can be used as alternatives to traditional semiconductors. In the present work, indium phthalocyanine chloride (ClInPc) is compressed to form a bulk structure (pellet). The prepared ClInPc pellet is characterized by differential scanning Calorimetry (DSC), and impedance spectroscopy in the frequency range of 0.15–100 kHz and at different temperatures (293–393 K). The DSC analysis of the ClInPc shows only one order phase transition at 196 °C. Additionally, the impedance spectroscopy reveals that the capacitance, dissipation factor, dielectric constant, and ac electrical conductivity of the ClInPc are temperature and frequency dependent. The ClInPc also exhibits a high capacitance of order 2–12 nF. Further, the dielectric constant of such material increases by increasing the temperature which involves the distribution of relaxation times. Furthermore, the AC conductivity follows Jonscher’s universal power law σac = AωS. The temperature dependent exponents S and m also outweigh the correlated barrier hopping (CBH) model for conduction mechanism.

Substrates with engineered roughness are studied with the aim of achieving broadband and omnidirectional photon harvesting in thin film devices. Light coupling across the interfaces of a photonic device is induced by uniaxial pseudo-periodic gratings formed in a self-organised fashion via de-focused ion beam sputtering (IBS). The optical properties of the textured interfaces are assessed both experimentally and numerically using finite difference time domain (FDTD) algorithm, quantitatively demonstrating the optimal geometries which favour broadband diffuse scattering of radiation across the Vis-NIR spectral range. Thin film amorphous silicon solar cells based on the nanostructured patterns have been numerically studied via FDTD to assess absorption enhancement in comparison to flat reference devices, finding a 25% increase of short-circuit current, in good agreement with the experiment. Similar light trapping experiments performed on prototypical solar cells employing a PTB7:PC61BM organic absorber, allow to extend the general validity of the results to a relevant class of materials in the view of photovoltaic applications.

Four different coordination compounds have been synthesized and structurally characterized in the reaction of aqueous solution of Mn(NO3)2 with pyridine-N-oxide co-ligands in the presence of KNCS, namely: [Mn(2-methylpyridine-N-oxide)(NCS)2]n (1); [Mn(3-methylpyridine-N-oxide)2(NCS)2]n (2), [Mn(4-methylpyridine-N-oxide)2(NCS)2(H2O)2] (3) and [Mn(4-cyanopyridine-N-oxide)2(NCS)2(H2O)]2 (4). Single crystal X-ray crystallography revealed the polymeric nature of the complexes as 2-D and 1-D for 1 and 2, respectively, with doubly μ(N,S) isothiocyanato bridging and μ(O,O) bridging methylpyridine-N-oxide ligands. The metal centers in the dinuclear complex 4 are linked by doubly μ(N,S) isothiocyanato bridges, whereas only terminal ligands are observed in the mononuclear complex 3. The magnetic properties of the complexes 1, 2 and 4 were investigated over the temperature range 2–300 K.

A series of pentacoordinate Co(II) complexes of the composition [Co(bpdmpz)Cl]ClO4 (1), [Co(bpdmpz)Cl]PF6 (2), [Co(bdmpzp)Cl]ClO4·H2O (3), [Co(bdmpzp)Cl]PF6 (4), [Co(tdmpza)Cl]ClO4 (5) and [Co(tdmpza)Cl]PF6 (6) (bpdmpz = bis[(2-pyridylmethyl)-(di(3,5-dimethyl-1H-pyrazolyl)methyl)]amine, bdmpzp = bis[(di(3,5-dimethyl-1H-pyrazolyl)methyl))-(2-pyridylmethyl)]amine and tdmpza = tris[di(3,5-dimethyl-1H-pyrazolyl)methyl)]amine) was prepared and thoroughly characterized. Single-crystal X-ray analyses of complexes 1–5 revealed that they possess very close molecular structures with a distorted trigonal bipyramidal geometry. The static DC magnetic experiments revealed the ZFS parameters pointing out small magnetic anisotropy (with the |D| values lying in a relative narrow range of 4.4–5.7 cm−1) and rhombicity (with the E/D parameters in the range of 0–0.26). The dynamic magnetic data revealed that AC susceptibility is temperature and frequency-dependent for 1, 2 and 3, and thus, these compounds belong to a group of field-induced pentacoordinate Co(II) single-molecule magnets (SMMs). The evaluation of magnetic data was also supported by the CASSCF/NEVPT2 calculations.

Five new metal(II) dicyanamide (dca) complexes with 4-hydroxymethylpyridine (4-OMP) and 4-methoxypyridine (4-MOP) have been synthesized, [Co(dca)2(4-OMP)2]n (1), [Cu(dca)2(4-OMP)2]n (2), [Cu(dca)2(4-MOP)2]n (3), [Cd(dca)2(4-MOP)2]n (4), [Zn(dca)2(4-MOP)2]n (5) and characterized by IR, UV–Vis spectroscopy and single crystal X-ray diffraction. The isostructural polymeric 1-D complexes feature double µ1,5-bridging dicyanamide ligands and terminal 4-OMP or 4-MOP ligands in trans-conformation around the distorted M(II) octahedra. The magnetic properties of complexes 1 and 2 are reported.

Four 1D coordination polymers catena -[Cu(4-HOCH 2 py)(μ 1,1 -N 3 )(μ 1,3 -N 3 )] ( 1 ), catena -[Cu(3-MeOpy) 2 (µ 1,1 -N 3 ) 2 ] ( 2 ), catena -[Cu(2-Br-4-Mepy)(µ 1,1 -N 3 ) 2 ] ( 3 ) and catena -[Cu(μ O,O -2-Cl-6-Menic)(μ 1,1 -N 3 )(MeOH)] ( 4 ) where 4-HOCH 2 py, 3-MeOpy, 2-Br-4-Mepy and 2-Cl-6-Menic represent 4-pyridylmethanol, 3-methoxypyridine, 2-bromo-4-methylpyridine and 2-chloro-6-methyl nicotinate anion, respectively have been synthesized, and structurally and magnetically characterized. Variable temperature magnetic susceptibility measurements over the temperature range 4.5–300 K revealed weak to moderate ferromagnetic coupling on going from complexes 1 ( J = 10.1 cm −1 ) and 3 ( J = 16 cm −1 ) to 4 ( J = 51.1) cm −1 . On the other hand, complex 2 displayed weak antiferromagnetic coupling ( J = −3.82 cm −1 ). The magnetic properties of the complexes are discussed in relation to the structural parameters of the bridging ligands.

Phosphate rock is the main source for production of phosphoric acid, which in most cases is associated with rare earth elements (REEs) and valuable actinoid element (U) that eventually enter and build up in the soil and could lead to environmental harm. So, their separation is the crucial task to purify the wet process phosphoric acid (WPPA). The extractant N-Propylpropan-1-amine was used for the first time in the extraction and separation of U and REEs from WPPA. The REEs have also been selectively stripped from U. A traditional log DM-log [Extractant] analysis shows that the Extractant has removed U and REEs as a complex of 2:1 (extractant: metal ion) ratio. The extraction of U (95.3%) and REEs (98.7%) was achieved using 1 M N-Propylpropan-1-amine in kerosene utilizing an aqueous-organic-phase ratio of one at room temperature for about 7 min. The selectivity or separation factor (SF) REEs /M > 74 and SF of U/M > 35 was obtained for all interfering metal ions examined. Additionally, over 98.8% REEs were stripped selectively from loaded N-Propylpropan-1-amine using 6.0 M HCl in three stages. The thermodynamic analysis demonstrated that U and REEs extraction by N-Propylpropan-1-amine is an exothermic process. Finally, phosphoric acid produced from Abu-Tartour phosphate rock was treated with optimum parameters of solvent extraction for U and REEs separation.

Monazite mineral is the main source of uranium and thorium, which are mainly associated with rare earth elements (REEs). So, their separation is the crucial task to satisfy their application for nuclear fuel. Dipropylamine was used for the first time in the selective extraction and separation of uranium and thorium from Monazite sulfate leach liquor. The extraction of thorium (98%) was achieved using dipropylamine in kerosene at pH 1; it was followed by selective extraction of uranium (97%) by Dipropylamine at pH 3. The thermodynamic analysis demonstrated that uranium (VI) and thorium (IV) extraction by dipropylamine is an exothermic process. From the stripped liquor (1 M H2SO4), Th and U were precipitated as oxalate and peroxide, respectively, for technological application. Thus, marketable pure thorium and uranium products were prepared in addition to rare earth concentrate.

Ten mononuclear rare earth complexes of formula [La(btfa)3(H2O)2] (1), [La(btfa)3(4,4′-Mt2bipy)] (2), [La(btfa)3(4,4′-Me2bipy)2] (3), [La(btfa)3(5,5′-Me2bipy)2] (4), [La(btfa)3(terpy)] (5), [La(btfa)3(phen)(EtOH)] (6), [La(btfa)3(4,4′-Me2bipy)(EtOH)] (7), [La(btfa)3(2-benzpy)(MeOH)] (8), [Tb(btfa)3(4,4′-Me2bipy)] (9) and (Hpy)[Eu(btfa)4] (10), where btfa = 4,4,4-trifuoro-1-phenylbutane-1,3-dionato anion, 4,4′-Mt2bipy = 4,4′-dimethoxy-2,2′-bipyridine, 4,4′-Me2bipy = 4,4′-dimethyl-2,2′-bipyridine, 5,5′-Me2bipy = 5,5′-dimethyl-2,2′-bipyridine, terpy = 2,2′:6′,2′-terpyridine, phen = 1,10-phenathroline, 2-benzpy = 2-(2-pyridyl)benzimidazole, Hpy = pyridiniumH+ cation) have been synthesized and structurally characterized. The complexes display coordination numbers (CN) eight for 1, 2, 9, 10, nine for 5, 6, 7, 8 and ten for 3 and 4. The solid-state luminescence spectra of Tb-9 and Eu-10 complexes showed the same characteristic bands predicted from the Tb(III) and Eu(III) ions. The Overall Quantum Yield measured (ϕTOT) at the excitation wavelength of 371 nm for both compounds yielded 1.04% for 9 and up to 34.56% for 10.

Three metal(II) dicyanamide (dca) complexes have been synthesized in presence of 2,6-lutidine-N-oxide (2,6-lut-NO): catena-{[M(μ1,5-dca)2(H2O)2](2,6-lut-NO)} (M = Mn(II) (1) , Co(II) (2), Ni(II) (3)), and characterized by IR, UV–Vis spectroscopy, single crystal and powder X-ray diffraction. The isostructural polymeric 1-D complexes feature double µ1,5-bridging dicyanamide ligands and terminal aqua ligands in trans-conformation around the distorted M(II) octahedra, whereas the 2,6-lutNO molecules are not ligated to the metal centers. The magnetic and thermal properties of the title complexes are reported.

In this study, commercial poly(propylene) (PP) hollow fiber membrane was used for desalination of highly saline water via VMD. The effect of operational conditions, such as feed temperature (i.e., 45–64 °C), feed flow rate (i.e., 0.4–0.6 L/min), feed concentration (i.e., 35–100 g/L), and vacuum pressure (i.e., 12.7–28 kPa (abs)), on hollow fiber performance was studied. The hot brine was circulated through the lumen side of the hollow fibers. The results demonstrated that the water permeate flux of about 66 (kg/m 2 h) was achieved at the operating conditions defined by 35 g/L, 65 °C, 0.6 L/min (pertaining to feed concentration, temperature, and flow rate, respectively) under 12.7 kPa (abs) vacuum pressure, whereas salt rejection was 99.99% and the conductivity of the permeate was less than 10 (μS/cm). In order to minimize the number of experiments and optimize the influence of operating conditions on permeate flux, Taguchi method was used and ANOVA was implemented to determine the contribution of each factor to the observed output. The findings revealed that the feed temperature was the most influential factor in determining the permeation flux, followed by vacuum pressure, feed concentration and feed flow rate.