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Nine new cobalt(II) compounds, trans-[Co(LPAQ)2(Py)2] (1), trans-[Co(LPAQ)2(3-MePy)2] (2), tran s-[Co(LMeAQ)2(Py)2] (3), trans-[Co(LOMeAQ)2(Py)2] (4), trans-[Co(LOEtAQ)2(Py)2]·2(H2O) (5), tran s-[Co(LCAQ)2(Py)2] (6), trans-[Co(LBAQ)2(Py)2] (7), ci s-[Co(LBAQ)2(3-MePy)2] (8a) and tran s-[Co(LBAQ)2(3-MePy)2]·2(3-MePy) (8b) (primary ligand: LXAQ = substituted 5-[(E)-2-(aryl)-1-diazenyl]quinolin-8-olate; secondary ligands: Py = pyridine, 3-MePy = 3-methylpyridine), have been synthesized and characterized by elemental analysis, IR and UV-vis spectroscopy. Magnetic measurements of the cobalt compounds were performed in solution by 1H NMR spectroscopy using the Evans’ method while their redox properties were studied by cyclic voltammetry. Single-crystal X-ray diffraction analysis of the compounds revealed their octahedral geometries and trans configuration, except for 8a, which has a cis configuration. Intermolecular noncovalent interactions were detected, π···π interactions in 5, C – H···π interactions in 2 and C – H···π edge-to-face (T-shaped) arrangements in 3, 4, 6, and 7.

Crystals of plasmonic metal nanoparticles have intriguing optical properties. They reach the regimes of ultrastrong and deep strong light-matter coupling, where the photonic states need to be included in the simulation of material properties. We propose a quantum description of the plasmon polaritons in supercrystals that starts from the dipole and quadrupole excitations of the nanoparticle building blocks and their coupling to photons. Our model excellently reproduces results of finite difference time domain simulations. It provides detailed insight into the emergence of the polariton states. Using the example of a face centered cubic crystals we show that the dipole and quadrupole states mix in many high symmetry directions of the Brilouin zone. A proper description of the plasmon and plasmon-polariton band structure is only possible when including the quadrupole-derived states. Our model leads to an expression of the reduced coupling strength in nanoparticle supercrystals that we show to enter the deep strong coupling regime for metal fill fractions above $0.8$. In addition to the plasmon-polariton energies we analyse the relative contributions of the dipole, quadrupole, and photonic states to their eigenfunctions and are able to demonstrate the decoupling of light in the deep strong coupling regime. Our results pave the way for a better understanding of the quantum properties of metallic nanoparticle supercrystals in the ultrastrong and deep-strong coupling regime., 30 pages, 6 figures

A new (tetrazole-saccharin)nickel complex is shown to be a valuable catalyst for the hydrosilative reduction of aldehydes under microwave radiation at low temperatures. With typical 1 mol% content of the catalyst (microwave power range of 5–15 W) most reactions are complete within 30 min. The Ni(II)-catalyzed reduction of aldehydes, with a useful scope, was established for the first time by using this catalyst, and is competitive with the most effective transition-metal catalysts known for such transformation. The catalyst reveals tolerance to different functional groups, is air and moisture stable, and is readily prepared in straightforward synthetic steps. Supported by experimental data and DFT calculations, a plausible reaction mechanism involving the new catalytic system is outlined.

A series of four new long chain triorganotin(IV) esters containing a diazenyl- and an imino-groups appended with ferrocene scaffold were designed and synthesized. Ferrocene based metallo pro-ligands H'HFcL1 and H'HFcL2 were obtained by reacting isomeric 3-/4-ferrocenylanilines with 2-[(E)-2-(3-formyl-4-hydroxyphenyl)-1-diazenyl]benzoic acid, which upon reactions with appropriate triorganotin(IV) precursors yielded compounds namely, [nBu3Sn(HFcL1)] 1, [Ph3Sn(HFcL1) 2, [nBu3Sn(HFcL2)] 3 and [Ph3Sn(HFcL2) 4. Compounds 1–4 have been characterized by elemental analysis and their spectroscopic properties were investigated using IR, UV-Vis and NMR spectroscopic techniques. The molecular structures of H'HFcL1 and two representative heterobimetallic compounds 3 and 4 have been determined by X-ray crystallography. Compound 3 is a 1D polymer and 4 is a discrete molecule; their structural differences relative to those of H'HFcL1 clearly indicate the influence of the binding of the tin cluster. The redox properties of the metallo pro-ligands and their compounds were also investigated by cyclic voltammetry.

In the past few decades, a generalized awareness and concern for sustainability issues has been gaining increasing relevance. Resources mapping (as well as time and cost) is an important task for decision-making toward sustainable production, and the multilayer stream mapping (MSM) method is an excellent approach to achieve it. Nevertheless, there are two potential barriers to the implementing MSM: (1) a constant feed of raw data from processes and production is required; and (2) the difficulty in decision-making based on the information supplied by MSM (with dozens of performance ratios per board). In this chapter a path is presented to overcome these two barriers. First, by proposing the link of MSM to an existing Internet-of-Things platform, taking advantage of the digitalization advent brought about by the Industry 4.0 revolution. Second, by proposing an optimization algorithm (integrated with discrete event simulation) that supports and facilitates the decision-making based on MSM. In addition to describing the proposed optimization approach, an application case study based on real industrial data from a company is presented and discussed.

Nine new cobalt(II) compounds, trans-[Co(LPAQ)2(Py)2] (1), trans-[Co(LPAQ)2(3-MePy)2] (2), trans-[Co(LMeAQ)2(Py)2] (3), trans-[Co(LOMeAQ)2(Py)2] (4), trans-[Co(LOEtAQ)2(Py)2]·2(H2O) (5), trans-[Co(LCAQ)2(Py)2] (6), trans-[Co(LBAQ)2(Py)2] (7), cis-[Co(LBAQ)2(3-MePy)2] (8a) and trans-[Co(LBAQ)2(3-MePy)2]·2(3-MePy) (8b) (primary ligand: LXAQ = substituted 5-[(E)-2-(aryl)-1-diazenyl]quinolin-8-olate; secondary ligands: Py = pyridine, 3-MePy = 3-methylpyridine), have been synthesized and characterized by elemental analysis, IR and UV-vis spectroscopy. Magnetic measurements of the cobalt compounds were performed in solution by 1H NMR spectroscopy using the Evans’ method while their redox properties were studied by cyclic voltammetry. Single-crystal X-ray diffraction analysis of the compounds revealed their octahedral geometries and trans configuration, except for 8a, which has a cis configuration. Intermolecular non-covalent interactions were detected, π···π interactions in 5, C–H···π interactions in 2 and C–H···π edge-to-face (T-shaped) arrangements in 3, 4, 6 and 7.

Although several strategies have been established to circumvent the limitations of platinum-based chemotherapy, the basic problems still persist. For this purpose, the new series of heterobimetallic formulations [FcLnSnPh3] (1, 3, and 9)], [FcLnSnBu3]n (2, 4 and 8), [FcL3SnCy3] (10), and [FcL3SnR3(MeOH)] (R = Me (5), Et (6), or Pr (7)), where FcLn (n = 1–3) refers to the isomeric 2-/3-/4-ferrocenylbenzoates, was synthesized which can target cancer cells and successively support functional iron deficiencies during chemotherapy. Compounds 1–10 have been characterized by elemental analysis, and their spectroscopic properties were investigated using IR, NMR, electronic, and fluorescence techniques. The molecular structures of metallo proligands FcL1H and FcL3H and the six heterobimetallic compounds 2, 3, 5–7, and 10 have been determined by X-ray crystallography. The redox properties of FcLnH and their compounds 1–10 were also investigated by cyclic voltammetry. In vitro cytotoxic activities of compounds 1–4, ...

This work describes the preparation of a series of platinum–aminocarbene complexes [PtCl{C(N=Ca(C6R2R3R4R5CONb))=N(H)R1}(CNR1)]a–b (8–19, 65–75% isolated yield) via the reaction of cis-[PtCl2(CNR1)2] (R1 = Cy 1, t-Bu 2, Xyl 3, 2-Cl-6-MeC6H34) with 3-iminoisoindolin-1-ones HN=Ca(C6R2R3R4R5CONbH) (R2–R5 = H 5; R3 = Me, R2, R4, R5 = H 6; R3, R4 = Cl, R2, R5 = H 7). New complexes 17–19 were characterized by elemental analyses (C, H, N), ESI+-MS, Fourier transform infrared spectroscopy (FT-IR), one-dimensional (1H, 13C{1H}), and two-dimensional (1H,1H correlation spectroscopy (COSY), 1H,13C heteronuclear multiple quantum correlation (HMQC)/1H,13C heteronuclear single quantum coherence (HSQC), 1H,13C heteronuclear multiple bond correlation (HMBC)) NMR spectroscopy, and authenticity of known species 8–16 was confirmed by FT-IR and 1H and 13C{1H} NMR. Complexes 8–19 were assessed as catalysts for hydrosilylation of terminal alkynes with hydrosilanes to give vinyl silanes, and complex [PtCl{C(N=Ca(C6H3(5-Me)CONb))=N(H)(2-Cl-6-MeC6H3)}{CN(2-Cl-6-MeC6H3)}]a−b (18) showed the highest catalytic activity. The catalytic system proposed operates at 80–100 °C for 4–6 h in toluene and with catalyst loading of 0.1 mol %, enabling the reaction of a number of terminal alkynes (PhC≡CH, t-BuC≡CH, and 4-(t-Bu)C6H4C≡CH) with hydrosilanes (Et3SiH, Pr3SiH, i-Pr3SiH, and PhMe2SiH). Target vinyl silanes were prepared in 48–95% yields (as a mixture of α/β isomers) and with maximum turnover number of 8.4 × 103. Hydrosilylation of internal alkynes (PhC≡CPh, Me(CH2)2C≡C(CH2)2Me, and PhC≡CMe) with hydrosilanes (Et3SiH, PhMe2SiH) led to the corresponding trisubstituted silylated alkenes in 86–94% yields. Initial observations on the mechanism of the catalytic action of platinum–ADC catalysts 8–19 suggested a molecular catalytic cycle.

A novel eco-friendly KA oil synthesis at room temperature (up to 25% yield) via solvent-free cyclohexane oxidation using Sn 1 − x Co x O 2 − δ ( x = 0, 0.01 or 0.05) nanoparticles as catalyst (TON up to 2 × 10 3 ) is here reported. These nanoparticles are the first SnO 2 - based material able to catalyze the oxidation of alkanes. The most active nanocatalyst was the Sn 0.95 Co 0.05 O 2 − δ , allowing an easy recovery and reuse, at least for five consecutive cycles, maintaining high selectivity concomitant with 92% of its initial activity.

This paper reports on the single-pot efficient oxidative functionalization of alkanes and alcohols, under mild conditions, catalysed by Au nanoparticles supported on Al2O3, Fe2O3, ZnO and TiO2. The obtained materials were tested for cyclohexane oxidation under mild conditions (60oC, atmospheric pressure), using an environmentally friendly oxidant (H2O2). The materials were also tested in the oxidation of benzyl alcohol and methylbenzyl alcohol, in the presence of t-butyl hydroperoxide as oxidant, under microwave irradiation. Concerning cyclohexane oxidation, all materials were highly selective towards the formation of cyclohexanol and cyclohexanone. No traces of by-products were detected under optimized conditions. Au on Fe2O3 led to the best results (13.5% yield). This system showed an interesting almost exclusive formation of cyclohexanol at 4 h reaction time. Catalyst recycling was tested up to 5 cycles, and the catalyst maintained almost the original level of activity after 3 cycles with no significant leaching. Concerning the oxidation of benzyl alcohol or methylbenzyl alcohol, all materials were highly selective towards the formation of benzaldehyde or acetophenone, respectively. No traces of by-products were detected. Addition of Au increased the alcohol conversion from 5% ( TiO2) to 91% (Au/TiO2), the latter being the best result obtained in this work. Recycling of Au/TiO2 was tested up to 10 cycles and catalytic activity remained at high level in the first 4 cycles.

An ideal plasmonic system for hot-electron generation allows the optical excitation of plasmons, limits radiation losses, exhibits strong non-radiative electron damping, and is made from scalable and cost-effective materials. Here we demonstrate the optical excitation of dark interlayer plasmons in bilayers of colloidal gold nanoparticles. This excitation is created by an antiparallel orientation of the dipole moments in the nanoparticle layers; it is expected to exhibit strongly reduced radiative damping. Despite the vanishing dipole moment, an incoming electromagnetic wave that is propagating normal to the surface will excite the dark mode due to field retardation. We observe a strong peak in the absorption spectrum of a colloidal gold bilayer (nanoparticle diameter = 46 nm); this peak is absent for a nanoparticle monolayer. The full width at half maximum of the dark mode is 230 meV for an ideal nanoparticle crystal and 320 meV for the structure produced by self-assembly out of solution. The position and width of the dark plasmon are efficiently tailored by the interparticle distance within the layer, nanoparticle size and layer number. We present time-resolved pump and probe experiments of hot-electron generation by bright and dark bilayer nanoparticle modes.

Reaction of the o-[(o-hydroxyphenyl)methylideneamino]benzenesulfonic acid (H2L) (1) with CuCl2&middot, 2H2O in the presence of pyridine (py) leads to [Cu(L)(py)(EtOH)] (2) which, upon further reaction with 2,2&rsquo, bipyridine (bipy), pyrazine (pyr), or piperazine (pip), forms [Cu(L)(bipy)]&middot, MeOH (3), [Cu2(L)2(&mu, pyr)(MeOH)2] (4), or [Cu2(L)2(&mu, pip)(MeOH)2] (5), respectively. The Schiff base (1) and the metal complexes (2&ndash, 5) are stabilized by a number of non-covalent interactions to form interesting H-bonded multidimensional polymeric networks (except 3), such as zigzag 1D chain (in 1), linear 1D chain (in 2), hacksaw double chain 1D (in 4) and 2D motifs (in 5). These copper(II) complexes (2&ndash, 5) catalyze the peroxidative oxidation of cyclic hydrocarbons (cyclooctane, cyclohexane, and cyclohexene) to the corresponding products (alcohol and ketone from alkane, alcohols, ketone, and epoxide from alkene), under mild conditions. For the oxidation of cyclooctane with hydrogen peroxide as oxidant, used as a model reaction, the best yields were generally achieved for complex 3 in the absence of any promoter (20%) or in the presence of py or HNO3 (26% or 30%, respectively), whereas 2 displayed the highest catalytic activity in the presence of HNO3 (35%). While the catalytic reactions were significantly faster with py, the best product yields were achieved with the acidic additive.

The self-assembly of metallic nanoparticles is a promising route to metasurfaces with unique properties for many optical applications, such as surface-enhanced spectroscopy, light manipulation, and sensing. We present an in-depth theoretical study of the optical properties of mono- and bilayers assembled from gold and silver nanoparticles. With finite-difference time-domain simulations, we predict the occurrence of two plasmon modes, a bright and a dark mode, which exhibit symmetric and antisymmetric dipole configurations between the layers, respectively. The dark mode resonance energy depends sensitively on the size of the particles and the interparticle gaps. Hotspots with a nearfield intensity enhancement of up to 3000 are expected, which, together with the fact that the dark mode is roughly four times narrower than the bright mode, reveals how promising these materials are for spectroscopy purposes., Main Text: 34 pages with 14 Figures Supporting Information: 7 pages with 6 Figures To be published in The Journal of Physical Chemistry C

In this work, we report the synthesis of formamides via solvent free N-formylation of amines using known arylhydrazones of malononitrile including sodium 2-(2-(dicyanomethylene)hydrazinyl)benzenesulfonate (I), 2-(2-(dicyanomethylene)hydrazinyl) benzoic acid (II) and its Cu(II) complex (III) as catalysts at room temperature. These catalysts are highly active and the scope of the method was investigated using several heterocyclic, aromatic and aliphatic amines as substrates, which produced the corresponding formamides in high yields. The remarkable advantages of this method are the elimination of toxic solvents, operational simplicity, easy workup procedure, excellent yields and avoidance of column chromatography.

This paper presents a building block approach to design a reconfigurable discriminator (RD), which is the core circuit in frequency identification receivers. The RD is used to identify an unknown signal; the output of the circuit determines a frequency subband where the unknown signal falls into. The proposed building block design approach is scalable and can be used to produce any multibit RD. This design approach can be used to produce RD circuits with more or less resolution for a fixed band of operation, according to the number of bits used for a given design. The building block approach is demonstrated through the design of a 4-bit RD. This design is a two-port device that provides a series readout and can produce 4 bits for frequency identification. The device operates from 1 to 4 GHz, implemented by microstrip lines and PIN diode switches. Simulated and measured responses are in agreement.

The catalytic activity of aqua complexes of the group III metals [M(H2O)n]3+ (M = Ga, In, Sc, n = 6; M = Y, n = 8; M = La, n = 9) towards the oxidation of olefins with H2O2 was investigated in detail by theoretical (DFT) methods. It was predicted and then confirmed in a preliminary experiment that these complexes formed from simple soluble salts in aqueous medium are able to efficiently catalyse the olefin oxidation. The reaction occurs via two competitive reaction channels which are realized concurrently, i.e. (i) hydroperoxidation of the allylic C atom(s) via a radical Fenton-like mechanism involving HO˙ radicals and leading to alkyl hydroperoxides ROOH and (ii) epoxidation of the CC bond through a one-step mechanism involving oxygen transfer from the hydroperoxo ligand in an active catalytic form [M(H2O)n−k(OOH)]2+ (M = Ga, In, Y, La, k = 2; M = Sc, k = 1) to the olefin molecule and leading to epoxides and/or trans-diols. Other concerted and stepwise mechanisms of the epoxidation were also considered but found less favourable.

Water-soluble compounds [VOCl2{CH3SO2OCH2C(pz)3}] (pz = pyrazol-1-yl) 1, [FeCl2{CH3SO2OCH2C(pz)3}] 2, [NiCl2{CH3SO2OCH2C(pz)3}] 3 and [Cu{CH3SO2OCH2C(pz)3}2](OTf)24 were obtained by reactions between the corresponding metal salts and 2,2,2-tris(pyrazol-1-yl)ethyl methanesulfonate, CH3SO2OCH2C(pz)3. They were isolated as air-stable solids and fully characterized by IR, FTIR, NMR (for 2), EPR (for 1), ESI-MS(+/−), elemental analysis and (for 4) single-crystal X-ray diffraction. In all, half- (1–3) or full-sandwich (4), compounds the C-scorpionate ligand shows the N,N,N-coordination mode. 3 and 4 appear to provide the first examples of a Ni(II) and a full-sandwich Cu(II) compound respectively, bearing that scorpionate ligand. Compound 3 is the first Ni(II) tris(pyrazol-1-yl)methane type complex to be applied as catalyst for the oxidation of alkanes. Compounds 1–4 exhibit catalytic activity for the peroxidative (with aq. H2O2) oxidation, in water/acetonitrile medium and under mild homogeneous conditions, of cyclooctane to the corresponding alcohol and ketone (yields up to ca. 27%). The effect of the presence of additives, such as nitric acid or pyridine, was studied.

New nickel(II) compounds, viz. trans-[Ni(LHAQ)2(Py)2]·C6H6 (1), cis-[Ni(LHAQ)2(3-MePy)2] (2), cis-[Ni(L2−MeAQ)2(3-MePy)2] (3), trans-[Ni(L4−MeAQ)2(Py)2]·C6H6 (4), trans-[Ni(L4−OMeAQ)2(Py)2]·C6H6 (5), trans-[Ni(L4−OEtAQ)2(Py)2]·C6H6 (6), trans-[Ni(L4−BrAQ)2(Py)2]·C6H6 (7) and trans-[Ni(L4−ClAQ)2(3-MePy)2]·2(3-MePy) (8) (primary ligands: LXAQ = substituted 5-[(E)-2-(aryl)-1-diazenyl]quinolin-8-olate; secondary ligands: Py = pyridine or 3-MePy = 3-methylpyridine) have been synthesized and characterized by elemental analysis, IR, UV–vis spectroscopy. The magnetic susceptibilities of the compounds were also measured. Single-crystal X-ray diffraction analysis of the compounds revealed octahedral geometries with trans configurations for 1, 4–8 and cis configurations for 2 and 3. The occurrence of intramolecular Ni⋅⋅⋅Hpyridine interactions in 2 and in 3, may account for additional stabilization of their assemblies at least in the solid state. The effective magnetic moment (μeff) in the range 3.02–3.40 BM agree with the expected values for octahedral Ni(II) cations with two unpaired electrons. Ni(II) compounds were also screened for their antimicrobial activity.

We demonstrate the excitation of dark plasmon modes with linearly polarized light at normal incidence in self-assembled layers of gold nanoparticles. Because of field retardation, the incident light field induces plasmonic dipoles that are parallel within each layer but antiparallel between the layers, resulting in a vanishing net dipole moment. Using microabsorbance spectroscopy we measured a pronounced absorbance peak and reflectance dip at 1.5 eV for bi- and trilayers of gold nanoparticles with a diameter of 46 nm and 2 nm interparticle gap size. The excitations were identified as dark interlayer plasmons by finite-difference time-domain simulations. The dark plasmon modes are predicted to evolve into standing waves when further increasing the layer number, which leads to 90% transmittance of the incident light through the nanoparticle film. Our approach is easy to implement and paves the way for large-area coatings with tunable plasmon resonance.

The dependence of the anti-Stokes Raman intensity on the excitation laser energy in carbon nanotubes is studied by resonant Raman spectroscopy. The complete resonant anti-Stokes and Stokes Raman profiles of the high-energy longitudinal phonon (${G}^{+}$) are obtained for (8,3), (7,5), (6,4), and (6,5) single chirality enriched samples. A high asymmetry between the intensity of the incoming and outgoing resonance is observed in the resonant Raman profiles. In contrast to Stokes scattering, anti-Stokes scattering is more intense at the outgoing resonance then at the incoming resonance. The resonance profiles are explained by a Raman process that includes the phonon-mediated interactions with the dark excitonic state. The chirality dependence of the Raman profiles is due to the variation in the exciton-phonon matrix elements, in agreement with tight-binding calculations. Based on the asymmetric Raman profiles we present the resonance factors for the Stokes/anti-Stokes ratios in carbon nanotubes.

A new catalytic system for the anaerobic oxidation of benzyl alcohols using a tetrazole-amino-saccharin organocatalyst has been established. In a solvent-free and microwave assisted process comprising aqueous tert-butyl hydroperoxide (TBHP) as oxidant, a variety of benzyl alcohols has been efficiently converted to aldehydes under mild conditions. Most reactions are complete within 30 min and the catalyst exhibits varied functional group compatibility. A catalytic cycle for the oxidation of the alcohols promoted by the tetrazole-amino-saccharin derivative is outlined involving radical species. DFT calculations performed for the oxidation of benzyl alcohol with and without organocatalyst show that the rate limiting step of the whole reaction is the cleavage of the O-O bond in TBHP with the subsequent hydrogen abstraction from the alcohol. The tetrazole-amino-saccharin organocatalyst assists the H-abstraction from benzyl alcohol by the bound HO center dot radical. The simplicity, selectivity and softness of reaction conditions of the studied organocatalytic protocol suggest a great potential for extensive use in synthetic chemistry. (C) 2017 Elsevier B.V. All rights reserved. Foundation for Science and Technology (FCT), Portugal [IF/01270/2013/CP1163/CT0007] FCT [SFRH/BPD/99851/2014, SFRH/BD/52370/2013, PD/00248/2012]

Theoretical (DFT) calculations predict that soluble Bi salts exhibit catalytic activity toward oxidation of olefins with H2O2. Reaction occurs via two competitive channels: (i) nonradical epoxidation of the C═C double bond and (ii) radical hydroperoxidation of the allylic C atom(s) with involvement of the HO• radicals, realized concurrently and leading to epoxide/diol and alkenylhydroperoxide products, respectively. The most plausible mechanism of epoxidation includes the substitution of a water ligand in the initial Bi aqua complex, hydrolysis of the coordinated H2O2, one-step oxygen transfer through a direct olefin attack at the unprotonated O atom of the OOH– ligand in [Bi(H2O)5(OOH)]2+, and liberation of the epoxide from the coordination sphere of Bi. The main conclusions of the theoretical calculations were confirmed by preliminary experiments on oxidation of cyclohexene, cyclooctene, and 1-octene with the systems Bi(NO3)3/H2O2/CH3CN + H2O and BiCl3/H2O2/CH3CN + H2O.

A simple catalytic system based on a soluble bismuth(III) salt, Bi(NO3)3/H2O2/HNO3/CH3CN + H2O, exhibits pronounced activity towards the homogeneous oxidation of inert alkanes with the yield of oxygenate products up to 32% and TON up to 112. The experimental selectivity parameters and kinetic data together with theoretical DFT calculations indicate that the reaction occurs via a free radical mechanism involving the formation of the HO˙ radicals which directly react with alkane molecules. The mechanism of the HO˙ generation (which is the rate limiting step of the whole process) includes the substitution of a water ligand for H2O2 in the initial aqua complex [Bi(H2O)8]3+, hydrolysis of the coordinated H2O2, second H2O-for-H2O2 substitution and the homolytic HO–OH bond cleavage in complex [Bi(H2O)4(H2O2)(OOH)]2+ (6). The relatively low overall activation energy for this process (ca. 20 kcal mol−1) is accounted for by the high lability and acidity of the Bi aqua complexes and tremendous activation of coordinated H2O2 in 6 towards homolysis.

This paper presents the design and simulated results of a Phase Shifter where the delay lines have been designed using the Hilbert's Fractal Line. Simulated results for fractal lines' group delay and PIN diode switch are also presented. Using the fractal lines allowed for a much more compact design when compared to traditional delay lines. Phase shift simulated results are in good accordance with theory.

Cyber-physical systems are characterised by a massive and tight interaction between computer systems and physical components. Hybrid systems provide an abstraction for modelling cyber-physical systems by featuring the integration of discrete and continuous behavioural aspects. Simulation is an important tool for validating hybrid system models, which are often too complex to be treated using other validation and verification techniques. Motivated by the industrial need for such tools, we propose a strategy (h-NAT2TEST) for simulation of hybrid systems from natural-language requirements. Using the proposed approach, one writes the system specification using a controlled natural language, from which an informal semantics is automatically inferred based on the case grammar theory. Then, a formal representation is built considering a model of hybrid data-flow reactive systems (h-DFRS). Finally, in order to allow for rigorous simulation, an Acumen specification is derived from the h-DFRS model. Simulation is supported by the Acumen modelling environment. A DC-DC boost converter is used as a case study to illustrate the overall approach.

Aminocarbene complexes cis-[PtCl2{ C (N(H)N = CR2R3)=N(H)R1}(CNR1)] (7–15) prepared via the nucleophilic addition of hydrazones H2N–N=CR2R3 [R2, R3 = Ph 4; R2/R3 = 9H-fluorenyl 5; R2 = H, R3 = 2-(OH)C6H4 6] to cis-[PtCl2(CNR1)2] [R1 = cyclohexyl (Cy) 1, 2,6-Me2C6H3 (Xyl) 2, 2-Cl-6-MeC6H3 3] were evaluated as catalysts for the hydrosilylation of terminal alkynes with trisubstituted silanes giving vinyl silanes. The optimized catalytic system runs at 80–100 °C in dry toluene for 3–6 h with a typical catalyst loading of 0.1 mol%. A range of substrates with different steric hindrance and activity (Et3SiH, Pr3SiH, iPr3SiH, and PhMe2SiH as silanes; PhC CH, tBuC CH, and 4-(tBu)C6H4C CH as alkynes) were successfully transformed into the target silylated products in 83–99% yields attesting the versatility of our catalytic system. Decreasing the catalysts loading to 10−3 mol% guaranteed the maximum TONs of 4.0 × 104 and TOFs of 1.7 × 103 (h−1) that were accomplished within 24 h of the reaction.

The Ni(II) and Zn(II) complexes [MCl(Tpms(Ph))] (Tpms(Ph) = SO3C(pz(Ph))3, pz = pyrazolyl; M = Ni 2 or Zn 3) and the Cu(II) complex [CuCl(Tpms(Ph))(H2O)] (4) have been prepared by treatment of the lithium salt of the sterically demanding and coordination flexible tris(3-phenyl-1-pyrazolyl)methanesulfonate (Tpms(Ph))(-) (1) with the respective metal chlorides. The (Tpms(Ph))(-) ligand shows the N3 or N2O coordination modes in 2 and 3 or in 4, respectively. Upon reaction of 2 and 3 with Ag(CF3SO3) in acetonitrile the complexes [M(Tpms(Ph))(MeCN)](CF3SO3) (M = Ni 5 or Zn 6, respectively) were formed. The compounds were obtained in good yields and characterized by analytic and spectral (IR, (1)H and (13)C{(1)H} NMR, ESI-MS) data, density functional theory (DFT) methods and {for 4 and [(n)Bu4N](Tpms(Ph)) (7), the latter obtained upon Li(+) replacement by [(n)Bu4N](+) in Li(Tpms(Ph))} by single crystal X-ray diffraction analysis. The Zn(II) and Cu(II) complexes (3 and 4, respectively) act as efficient catalyst precursors for the diastereoselective nitroaldol reaction of benzaldehydes and nitroethane to the corresponding β-nitroalkanols (up to 99% yield, at room temperature) with diastereoselectivity towards the formation of the anti isomer, whereas the Ni(II) complex 2 only shows a modest catalytic activity.

The experimental conditions (solvent, base, temperature and oxidant) for allylic and benzylic oxidation reactions catalyzed by dirhodium(II)/N-heterocyclic carbene (NHC) complexes were optimized for the first time in this work. The oxidations of cyclohexene and fluorene were used as model reactions. Two optimized experimental conditions for both types of oxidations were found, which resulted in their ketone [aerobic conditions, 40 °C, 1 equiv. tBuOOH (TBHP)] or tert-butyl peroxide derivatives (anaerobic conditions, 25 °C, 2 equiv. TBHP). The dirhodium(II) complexes undergo a single-electron reversible oxidation by cyclic voltammetry in CH2Cl2, which is assigned to the Rh24+/Rh25+ redox couple at an oxidation potential that is lowered upon sequential axial coordination of further ligands to the Rh–Rh centre. The oxidation potential is discussed in terms of the electron-donor character of the NHC ligand, which was shown to act as an effective electron-releaser to the Rh24+ centre, and the electrochemical behaviour is compared to the observed catalytic activity.

Synthesis and spectroscopic properties of seven new dibutyltin(IV) compounds of 2-{(E)-4-hydroxy-3-[(E)-4-(aryl)iminomethyl]phenyldiazenyl}benzoic acids (LnHH'; n=2-8) with general formula {[Bu2Sn(LnH)]2O}2 (1-7) are reported. The compounds were characterized by elemental analysis and by UV-Visible, fluorescence, IR, 1H, 13C and 119Sn NMR spectroscopies. Solid state structures of dibutyltin(IV) compounds 1-3, 6 and 7 were accomplished from single crystal X-ray crystallography which reveal the common ladder-type structure with two endo- and two exo-Sn atoms. The redox properties of LnHH' (n=2-4, 7 and 8) and their diorganotin(IV) compounds 1-3, 6 and 7 were also investigated by cyclic voltammetry. In general, the dibutyltin(IV) derivatives exhibited significant in vitro cytotoxic potency towards A375 (melanoma) and HCT116 (colon carcinoma) cell lines as determined by several experiments, like Live and Dead assay, MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) cell viability assay, LDH (lactate dehydrogenase), cleavage of caspases and PARP (poly(ADP-ribose)polymerase), and DNA fragmentation. Dibutyltin(IV) compounds increase cell death without cytolysis and decreases membrane fluidity, without interfering with p53. Among the dibutyltin(IV) compounds, compound 6 was found to be the most potent, with an IC50 value of 78nM. A mechanism of action for tumor cell death is proposed.

Reaction of the tris(3-phenylpyrazolyl)methane sulfonate species (Tpms Ph )Li with the copper(I) complex [Cu(MeCN) 4 ][PF 6 ] affords [Cu(Tpms Ph )(MeCN)] 1 . The latter, upon reaction with equimolar amounts of cyclohexyl- (CyNC) or 2,6-dimethylphenyl (XylNC) isocyanides, or excess CO, furnishes the corresponding Cu(I) complexes [Cu(Tpms Ph )(CNR)] (R = Cy 2 , Xyl 3 ) or [Cu(Tpms Ph )(CO)] 4 . The ligated isocyanide in 2 or 3 (or the acetonitrile ligand in 1 ) is displaced by 3-iminoisoindolin-1-one to afford 5 , the first copper(I) complex containing an 3-iminoisoindolin-1-one ligand. The ligated acetonitrile in 1 undergoes nucleophilic attack by methylamine to give the amidine complex [Cu(Tpms Ph ){MeC(NH)NHMe}] 6 , whereas only the starting materials were recovered from the attempted corresponding reactions of 2 and 3 with methylamine. Complexes 1 or 6 form the trinuclear hydroxo-copper(II) species [(μ-Cu){Cu(μ-OH) 2 (Tpms Ph )} 2 ] 7 upon air oxidation in moist methanol. In all the complexes the scorpionate ligand facially caps the metal in the N , N , O -coordination mode.