Synthesis and characterization of copper(II), cobalt(II), nickel(II), and iron(III) complexes with two diamine Schiff bases and catalytic reactivity of a chiral diamine cobalt(II) complex

New transition metal complexes of Co(II), Cu(II), Ni(II), and Fe(III) of the ligands 6,6′-(1E,1′E)-(4,5-dimethyl-1,2-phenylene)bis(azan-1-yl-1-ylidene)bis(methan-1-yl-1-ylidene)bis(7-hydroxy-5-methoxy-2-methyl-4H-chromen-4-one) H₂L¹ and 6,6’-(1E,1′E)-cyclohexane-1,2-diylbis(azan-1-yl-1-ylidene)bis(methan-1-yl-1-ylidene)bis(7-hydroxy-5-methoxy-2-methyl-4H-chromen-4-one) H₂L² have been prepared and characterized using physio-chemical and spectroscopic methods. The results obtained for the complexes indicated that the geometries of the metal centres are either square planar or octahedral. Cyclopropanation reactions of unactivated olefins by ethyldiazoacetate (EDA) in the presence of [L¹Cu]·H₂O, [L²Cu]·2H₂O and [L²*Co]·2H₂O as catalysts were examined. The results showed that only [L²*Co]·2H₂O can act as a catalyst for the cyclopropanation reaction of unactivated olefins with very high selectivity (up to 99% based on EDA).     

Intermolecular aza‐wittig reaction: One‐step synthesis of pyrazolo[1,5‐a]pyrimidine and imidazo[1,2‐b]pyrazole derivatives

Pyrazolo[1,5‐a]pyrimidine and imidazo[1,2‐b]pyrazole derivatives were synthesized via intermolecular aza‐Wittig reaction of 5‐(triphenylphosphoranylideneamino)‐3‐phenylpyrazole 3 derived from 5‐amino‐3‐phenylpyrazole with some selected α‐chloroketones.     

A Mathematical Model for Short-Time Filtration in Poroelastic Media with Thermal Relaxation and Two Temperatures

In this work, we derive a set of governing equations for a mathematical model of generalized thermoelasticity in poroelastic materials. This model predicts finite speeds of propagation of waves contrary to the model of coupled thermoelasticity where an infinite speed of propagation is inherent. Next, we prove the uniqueness of solution of these equations under suitable conditions. We also obtain a reciprocity theorem for these equations. A thermal shock problem for a half-space composed of a poroelastic material saturated with a liquid is then considered. The surface of the half-space is assumed to be traction free, permeable, and subjected to heating. The Laplace transform technique is used to solve the problem. Numerical results for the temperature in the elastic body and fluid, displacement of the elastic body, velocity of the fluid, and stresses for both components are obtained and represented graphically.     

On thermodynamic self-consistency of generic axiomatic-nonextensive statistics

Generic axiomatic-nonextensive statistics introduces two asymptotic properties,to each of which a scaling function is assigned.The first and second scaling properties are characterized by the exponents c and d,respectively.In the thermodynamic limit,a grand-canonical ensemble can be formulated.The thermodynamic properties of a relativistic ideal gas of hadron resonances are studied,analytically.It is found that this generic statistics satisfies the requirements of the equilibrium thermodynamics.Essential aspects of the thermodynamic self-consistency are clarified.Analytical expressions are proposed for the statistical fits of various transverse momentum distributions measured in most-central collisions at different collision energies and colliding systems.Estimations for the freezeout temperature(T_(ch)) and the baryon chemical potential(μ_b) and the exponents c and d are determined.The earlier are found compatible with the parameters deduced from Boltzmann-Gibbs(BG) statistics(extensive),while the latter refer to generic nonextensivities.The resulting equivalence class(c,d) is associated with stretched exponentials,where Lambert function reaches its asymptotic stability.In some measurements,the resulting nonextensive entropy is linearly composed on extensive entropies.Apart from power-scaling,the particle ratios and yields are excellent quantities to highlighting whether the particle production takes place(non)extensively.Various particle ratios and yields measured by the STAR experiment in central collisions at 200,62.4 and 7.7 GeV are fitted with this novel approach.We found that both c and d 1,i.e.referring to neither BG-nor Tsallis-type statistics,but to(c,d)-entropy,where Lambert functions exponentially rise.The freezeout temperature and baryon chemical potential are found comparable with the ones deduced from BG statistics(extensive).We conclude that the particle production at STAR energies is likely a nonextensive process but not necessarily BG or Tsallis type.     

Metal-binding effects of sirtuin inhibitor sirtinol

Sirtinol, a Schiff base derived from 2-hydroxy-1-naphthaldehyde, is an inhibitor of sirtuin proteins, a family of deacetylases active in gene regulation and relevant to the study of cancer growth. The formation of copper(II) and zinc(II) complexes of sirtinol is investigated by spectroscopic and structural methods. The molecular structure of this protein inhibitor allows for coordination of first-row transition metals in both tridentate and bidentate fashion. In addition, assays in cultured breast cancer cells reveal that Cu^II(sirtinol?H)₂ and previously reported Fe^III(sirtinol?H)(NO₃)₂ present enhanced cytotoxicity when compared to the free ligand, and that the ferric complex causes an increase in intracellular oxidative stress. Transition metal coordination in the biological milieu could therefore contribute additional effects to the biological profile of sirtinol.     

Application of the aza-Wittig reaction for efficient synthesis of diversely substituted benzo[f]Chromeno[2,3-d]pyrimidine and benzo[f]chromeno[2,3-d][1,2,4]triazolopyrimidine derivatives

An efficient synthesis of novel benzo[f]Chromeno[2,3-d]pyrimidine and unknown benzo[f]chromeno[2,3-d][1,2,4]triazolopyrimidine derivatives is described utilizing ethyl-2-amino-4-phenyl-4H-benzo[f]chromene-3-carboxylate as precursor via aza-Wittig reaction. The process proved to be simple, high-yielding, and efficient.     

Correlated Markov Quantum Walks

We consider the discrete time unitary dynamics given by a quantum walk on ${\mathbb {Z}^d}$ performed by a particle with internal degree of freedom, called coin state, according to the following iterated rule: a unitary update of the coin state takes place, followed by a shift on the lattice, conditioned on the coin state of the particle. We study the large time behavior of the quantum mechanical probability distribution of the position observable in ${\mathbb {Z}^d}$ for random updates of the coin states of the following form. The random sequences of unitary updates are given by a site-dependent function of a Markov chain in time, with the following properties: on each site, they share the same stationary Markovian distribution and, for each fixed time, they form a deterministic periodic pattern on the lattice. We prove a Feynman–Kac formula to express the characteristic function of the averaged distribution over the randomness at time n in terms of the nth power of an operator M. By analyzing the spectrum of M, we show that this distribution possesses a drift proportional to the time and its centered counterpart displays a diffusive behavior with a diffusion matrix we compute. Moderate and large deviation principles are also proven to hold for the averaged distribution and the limit of the suitably rescaled corresponding characteristic function is shown to satisfy a diffusion equation. An example of random updates for which the analysis of the distribution can be performed without averaging is worked out. The random distribution displays a deterministic drift proportional to time and its centered counterpart gives rise to a random diffusion matrix, the law of which we compute. We complete the picture by presenting an uncorrelated example.     

Synthesis of 4‐amino‐3‐cyano‐2‐ methylsulfanyl‐1H‐[1,5]benzodiazepine,benzo[1,3]azole,and pyrazolobenzo[1,3]azole derivatives via a new utility of bis(methylsulfanyl)methylene derivatives

Novel polysubstituted 1,5‐benzodiazepine 5 , 2,2‐bis(methylthio)benzoxazoles 8a–d , 2,2‐bis‐ (acetyl)benzoxazole 8e , 2‐(3‐methyl‐1‐phenylpyrazolo‐ 4‐yl)benzoazole derivatives 16a–c , as well as the previously reported 2‐di[cyano(acetyl)‐methylene]benzothiazoles 7a,b have been obtained via a new utility of ketene dithioacetals 1a,b and 12 with aniline derivatives 2 . Rationales for the reactions pathways are presented. © 2004 Wiley Periodicals, Inc. Heteroatom Chem 15:407–412, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20031     

Benzofuranyl-pyran-2-ones, -pyridazines,and -pyridones from naturally occurring furochromones (visnagin and khellin)

The novel and versatile enaminones 2a,b were synthesized by treatment of visnaginone methyl ether 1a or khellinone methyl ether 1b with N,N-dimethylformamide dimethylacetal. They were reacted with hippuric acid or N-acetylglycine to yield benzofuran-5-yl-2H-pyran-2-ones 3a–d . The reaction of 2a,b with cyanoacetamide and malononitrile dimer in sodium ethoxide gave benzofuran-5-yl-pyridones 4a,b and [benzofuran-5-yl-1H-pyridine-2-ylidene] malononitrile 5a , respectively. Refluxing 2a,b with hydrazine hydrate or with hydroxyla- mine afforded benzofuran-5-yl-1H-pyrazoles 6a,b and benzofuran-5-yl-isoxazoles 7a,b , respectively. Moreover, 2a,b coupled with aryl diazonium salt in the presence of sodium hydroxide to yield 3-(benzofuran-5-yl)-2-aryl-hydrazono-3-oxo-propanals 8a,b which were excellent precursors for the synthesis of pyridazines 9–12 . © 2003 Wiley Periodicals, Inc. 15:85–91, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10219     

New Ni(II), Pd(II) and Pt(II) complexes coordinated to azo pyrazolone ligand with a potent anti‐tumor activity: Synthesis,characterization, DFT and DNA cleavage studies

The absolute necessity to fight some class of tumor is perceived as serious health concerns, so the discovery and development of effective anticancer agents are urgently needed. (E)‐4‐((2‐hydroxyphenyl)diazenyl)‐3‐phenyl‐1H‐pyrazol‐5(4H)‐one, HL, and its Ni(II), Pd(II) and Pt(II) complexes were synthesized and the biological activity was evaluated for antitumor, antioxidant and antimicrobial activity as well as DNA cleavage. Their structures were assigned depending on the elemental analysis, conductivity, magnetic moment, spectral measurements (IR, ¹HNMR, mass and UV–Vis) and thermal analysis. 3D molecular modeling using DFT method confirmed that the geometrical structures agree well with the suggested experimental ones. The antitumor activity was evaluated against four different cell lines using MTT assay. The ligand HL showed a potent cytotoxic activity compared to 5‐fluorouracil as a reference drug. For metal complexes, the order of activity was: Pd(II) > Ni(II) > Pt(II). A remarkable antioxidant activity for the ligand HL was recorded. It was higher than that of the metal complexes. Results of antimicrobial experiments revealed that all compounds were moderate to highly active against selected bacterial strains but inactive as antifungal except Pd(II) which showed a moderate antifungal activity. Gel electrophoresis showed insignificant nucleases activity for the ligand or its metal complexes even in the presence of H₂O₂ providing protection of DNA from damage. The antitumor activity of our compounds may be not due to DNA cleavage but may be referred to a mechanism similar to that of 5‐fluorouracil which interfere with DNA replication. The present work suggests the use of this ligand in the design and development of new anticancer drugs.