A 2D Co(II) coordination polymer based on 1,3,5-tris(1H-imidazol-1-yl)benzene: photocatalytic properties and theoretical analysis

Abstract

A new 2D Co(II) based coordination polymer (CP), {[Co₂(tib)₂(NO₃)₃(H₂O)₂·NO₃]_n (1), has been synthesized using 1,3,5-tris(1-imidazolyl)benzene (tib) ligand. The single crystal X-ray diffraction study indicates that 1 possesses an infinite 2D layer, which is further extended into a 3D supramolecular network via O–H···O hydrogen bonding interactions. Additionally, the thermogravimetric analysis (TGA) of CP indicates its decomposition temperature was about 268?°C. The UV/Vis diffuse-reflection spectrum of 1 indicates its semiconducting nature on the basis of which the photocatalytic properties of 1 against photodecomposition of organic dyes have been studied. The possible mechanism associated with the photocatalytic activity of 1 against organic dyes is addressed using density of states (DOS) calculations.     

Some MnIII-porphyrins with de-polymerization activity toward humic acid

Four Mn^III-porphyrin complexes, chloro(tetraphenylporphinato)Mn^III(1,6-diaminohexane), bromo(tetraphenylporphinato)Mn^III(1,6-diaminohexane), azido(tetraphenylporphinato)Mn^III(1,6-diaminohexane), and thiocyanato(tetraphenylporphinato)Mn^III(1,6-diaminohexane), have been synthesized. These complexes have been characterized using UV-Vis, IR, ESI-mass spectra, elemental analyses, magnetic susceptibility measurements, and conductivity measurement. The molar conductance values of these complexes in ethanol indicate non-electrolytes. The utility of these complexes in de-polymerization of coal using humic acid as the coal model has been tested by the optical density method.     

Synthesis,structure and properties of aquabis(2,4′-bipyridine)di(propionato-O)copper(II)

The title complex has been synthesized and characterized by elemental and thermal analysis, IR and electronic spectroscopy, conductivity studies and X-ray crystallography. In the crystal, the complex has two-fold symmetry and the copper atom adopts square pyramidal coordination. Bond valences for Cu were computed. Cu–O_(propionate) bonds are slightly stronger than the Cu–N bonds, and the Cu–O_(water) bond is distinctly weaker. Molecules are linked by O–H···O hydrogen bonds to form infinite hydrogen-bonded chains along the y axis.     

Triphenyltin chloride complexes containing bidentate organodiimines as effective antitumor agents

Three triphenyltin chloride complexes, [(Ph₃SnCl)₂?·?(bpy)_1.5] (1), [(Ph₃SnCl)₂.tbpe] (2), and [(Ph₃SnCl)₂?·?bpe] (3), were synthesized by reaction of triphenyltin chloride with 4,4′-bipyridine (bpy), trans-1,2-bis(4-pyridyl)ethylene (tbpe), and 1,2-bis(4-pyridyl)ethane (bpe) in water/acetonitrile. Both 2 and 3 are binuclear; each consists of two Ph₃SnCl molecules bridged by the bidentate ligand. Complex 1 consists of two crystallographically independent and chemically different coordination complexes, mononuclear and binuclear in equal proportion. The structures of these complexes were investigated by single-crystal X-ray analysis, elemental analyses, NMR spectroscopy as well as electronic absorption and emission spectroscopy. The three complexes exhibit in vitro antitumor activity against human breast cancer cell line, MCF7.     

On the critical behavior of the magnetization in high-dimensional Ising models

We derive rigorously general results on the critical behavior of the magnetization in Ising models, as a function of the temperature and the external field. For the nearest-neighbor models it is shown that ind4 dimensions the magnetization is continuous atT _c and its critical exponents take the classical values=3 and=1/2, with possible logarithmic corrections atd=4. The continuity, and other explicit bounds, formally extend tod>3 1/2. Other systems to which the results apply include long-range models ind=1 dimension, with 1/|x–y| couplings, for which 2/(–1) replacesd in the above summary. The results are obtained by means of differential inequalities derived here using the random current representation, which is discussed in detail for the case of a nonvanishing magnetic field.Research supported in part by NSF grant PHY-8301493 A02, and by a John S. Guggenheim Foundation fellowship (M.A.).     

Infrared asymptotic freedom of a hierarchical φ 3 6 lattice theory

For the weakly coupled lattice ₃ ⁶ theory in a hierarchical model approximation a nonperturbative renormalization group analysis in the spirit of Gawedzki and Kupiainen is performed to study the flow of the effective actions. We deduce a domain of attraction to the tricritical (Gaussian) fixed point. The two relevant coupling constants of the problem are controlled by analytic continuation to complex domains, tracing their images under the renormalization group iterations.     

Study of electron solvation in polar solvents using path integral calculations

A path-integral Monte Carlo algorithm for the simulation of electrons solvated in polar liquids is briefly outlined, and results are presented for the electron solvated in liquid water.     

Density functional theory for a model of nonuniform liquid metal in partially ionized states

Summary The problem of the electronic, ionic and atomic density profiles in a nonuniform liquid metal which can locally exist in partially ionized states is examined using the density functional formalism. Ions and electrons are allowed to bind into atoms through a ?reaction? governed by the mass action law. Formally exact equations for the density profiles are given in terms of the inverse response matrix of the nonuniform system, which consists of two terms: the first corresponding to to a mixture of ions, electrons and structureless atoms and the other to the atomic internal degrees of freedom. Approximate schemes are proposed for both contributions, stressing, in partieular, i) how ionization of the atoms arises with increasing density and the relation with Mott’s criterion for the metal-insulator transition, and ii) the usefulness of a weak-coupling assumption for interspecies correlations. This formalism used together with properly parametrized trial functions for the density profiles should be particularly useful for studying the liquid-vapour interface of alkali metals.

---

Riassunto Il lavoro usa il formalismo del funzionale di densità per discutere la determinazione dei profili di densità in un fluido non omogeneo che può trovarsi localmente in stati di ionizzazione parziale. Con riferimento specifico ai metalli alcalini, la formazione di atomi per legame di ioni ed electtroni è descritta come una ?reazione? governata dalla legge di azione di massa. Le condizioni di equilibrio microscopico del fluido sono espresse tramite una matrice di risposta in cui appaiono due contributi, associati rispettivamente ai gradi di libertà interni degli atomi e ad una miscela di tre specie di particelle senza struttura interna. Si propongono quindi schemi approssimati per il calcolo di questi due contributi, con attenzione particolare all’uso di teorie perturbative e alla relazione tra grado di ionizzazione locale e densità localle, in connessione col criterio di Mott per la transizione isolante-metallo. Il formalismo proposto è in particolare appropriato per lo studio dell’interfaccia liquido-vapore in metalli alcalini.

---

Резюме Используя функционала плотности, исследуется проблема профилей электронной, ионной и атомой ллотностей В неоднодном зидком металле, которий мозет локалщно существоватщ в частично иониэированных состояних. Ионы и электроны могут şвяэыватщся в атомщ череэ ?реакцию, определяемую эаконом дейşтвуюших масс. Приводятся формалщно точные уравнения для профнлеи плотности в термина⇆ обратной матрици отклика для неоднородной системы, которая состоит иэ двух чуленов: первий соответствует ссмеси ионов, электронов и бесстрктурных атмов и второй член соответствует атомным внутренним степеням свобды. Предлагаются приближенные схемы для обоых вкладов, обрашая особое бнмание, в частности, 1) как иониэация атомов воэликает бри увеличени влотности, на свяэы с критерием Мота для берехода ?металл-иеолятор?, и 2) на полеэносты предположения слабой свяэи для межвидовых кореляций. Предложенный Формалиэм, исполыеовалный вместе с параметриэованными пробными функциями для профилей плотнорти, окаэываетця оробенне полеэным для исследования грраницы ?жидкостъ-пар? в шелочлых металлах.

     

Return to equilibrium in theXY model

We prove that the locally perturbedXY model returns to equilibrium under the unperturbed evolution but the unperturbed model does not necessarily approach equilibrium under the perturbed evolution. In fact this latter property is false for perturbation by a local magnetization. The failure is directly attributable to the formation of bound states. If the perturbation is quadratic these problems are reduced to spectral analysis of the one-particle Hamiltonian. We demonstrate that the perturbed Hamiltonian has a finite set of eigenvalues of finite multiplicity together with some absolutely continuous spectrum. Eigenvalues can occur in the continuum if, and only if, the perturbation dislocates the system. Singular continuous spectrum cannot occur.     

Asymptotic behavior of fluctuations for the 1D Ising model in zero-temperature limit

Fluctuation of the average spin for one-dimensional Ising spins with nearest neighbor interactions are studied. The distribution function for the average spin is calculated for a finite volume, finite temperature, and finite magnetic field. As the volume increases and the temperature diminishes at zero magnetic field, there are two limits in which the probability distribution shows quite different behaviors: in the thermodynamic limit as the volume goes to infinity for finite temperature, small deviations of the fluctuations are described by a Gaussian distribution, and in the limit as the temperature vanishes for a finite volume, the ground states are realized with probability one. The crossover between these limits is analyzed via a ratio of the correlation length to the volume. The helix-coil transition in a polypeptide is discussed as an application.