Cyan-Blue Luminescence and Antiferromagnetic Coupling of CN-Bridged Tetranuclear Complex Based on Manganese(III) Schiff Base and Hexacyanoferrate(III)

A new tetranuclear cyanide-bridged Mn^III–Fe^III complex based on manganese(III) Schiff base and hexacyanoferrate(III) units, [Mn(L)(MeOH)₂][{Mn(L)}{Fe(CN)₆}{Mn(L)(MeOH)}].2MeOH, [H₂L?=?N,N′-bis(2-hydroxy-1-naphthalidenato)-1,2-diaminopropane] (1), has been synthesized and characterized by elemental analysis, UV–Vis, FT-IR, PXRD, single crystal X-ray analyses, magnetic and photoluminescence measurements. Complex 1 consist of one trinuclear cyanido-bridged anion, in which [Fe(CN)₆]^3? anion bridge [Mn(L)]⁺ and Mn(L)(MeOH)}]⁺ cations via two C≡N groups in the cis positions, and also one isolated manganese [Mn(L)(MeOH)₂]⁺ cation. DC magnetic susceptibility and magnetization studies showed that complex 1 indicates an antiferromagnetic coupling between low-spin Fe(III) and high-spin Mn(III) through the cyanide bridges. In addition, the complex 1 displays a strong cyan-blue luminescence emission in the solid state condition at room temperature. This behavior might be seen easily from the chromaticity diagram. Thus, the complex may be a good promising cyan-blue OLED developing electroluminescent materials for flatted or curved panel display applications due to the fact that it has such features.     

Theory and simulation in heterogeneous gold catalysis

This critical review covers the application of quantum chemistry to the burgeoning area of the heterogeneous oxidation by Au. We focus on the most established reaction, the oxidation of CO at low temperature. The review begins with an overview of the methods available comparing the treatment of the electron-electron interaction and relativistic effects. The structure of Au particles and their interaction with oxide reviews is then discussed in detail. Calculations of the adsorption and reaction of CO and O(2) are then considered and results from isolated and supported Au clusters compared (155 references).     

Synthesis, molecular structure, spectroscopic studies and second-order nonlinear optical behaviour of N,N'-(2-hydroxy-propane-1,3-diyl)-bis(5-nitrosalicylaldiminato-N,O)-copper(II)

N,N'-(2-Hydroxy-propane-1,3-diyl)-bis(5-nitrosalicylaldiminato-N,O)-copper(II) has been synthesized. The crystal structure has been determined by X-ray diffraction analysis, and linear optical characterization has been determined by UV-vis spectroscopy. It was found that the molecule under investigation has solvatochromic behaviour in the UV region, implying non-zero microscopic first hyperpolarizability. To reveal the microscopic nonlinear optical (NLO) properties, the static first hyperpolarizabilities (beta) and the electric dipole moments (mu) were evaluated by using the ab initio finite field (FF) method. According to the results of the FF calculations, the synthesized compound exhibits non-zero beta values, and it might have microscopic NLO behaviour.     

Distances entre exponentielles et puissances d’éléments de certaines algèbres de Banach

Let A be a Banach algebra which does not contain any nonzero idempotent element, let γ > 0, and let . We show that if then . We also show, assuming a suitable spectral condition on x, that if , then Received: 12 July 2006 Revised: 31 January 2007     

Specific heat and frequency shifts for the translational modes in ammonia solid I close to phase transition

The specific heat C(p) is correlated to the frequency shifts (1/nu)( partial differentialnu/ partial differentialT)(p) in ammonia solid I close to the melting point. Our calculated Raman frequencies for the translational modes of nu(T) (100 cm(-1)) and nu(T) (130 cm(-1)), are used for this correlation for the pressures of 0, 1.93 and 3.07 kbar in this crystalline system. We obtain that the specific heat varied linearly with the frequency shifts for those pressures studied and values of the slope dP(m)/dT were extracted. The observed behaviour of the ammonia solid I near the melting point is explained on the basis of our spectroscopic modification of the first Pippard relation.     

Approximate Symmetries and Conservation Laws with Applications

The relationship between the approximateLie-Backlund symmetries and the approximate conservedforms of a perturbed equation is studied. It is shownthat a hierarchy of identities exists by which thecomponents of the approximate conserved vector or theassociated approximate Lie-Backlund symmetries aredetermined by recursive formulas. The results areapplied to certain classes of linear and nonlinear waveequations as well as a perturbed Korteweg-de Vriesequation. We construct approximate conservation laws forthese equations without regard to aLagrangian.     

Characterization of extracts from Papaver rhoeas and potential valorization of these extracts in dyeing applications

The aim of our work is to study the dyeing properties of extracts from natural sources such as Papaver rhoeas by modifying the conditions of the dyeing process, choosing other substrates that could be pretreated by innovative and environmentally friendly processes. The results obtained show a fairly high fixation of the extracts on the natural and artificial fibers. The use of mordants allowed the dye to be better fixed on the dyed fibers and to give several shades to the fabric. The rate of essential oil contained in Papaver rhoeas was considered important by the Clevenger process. Screening of extractive revealed the presence of polyphenols, saponins, sterols, alkaloids and flavonoids. In this study, the extractive from Papaver rhoeas was investigated as textile dyestuff.     

Matching extension in the powers of n-connected graphs

Let G be a graph on p vertices. Then for a positive integer n₁ G is said to be n-extendible if (i) n < p/2, (ii) G has a set of n independent edges, and (iii) every such set is contained in a perfect matching of G. In this paper we will show that if p is even and G is n-connected, then G^k is -extendible for every integer k ≥ 2 such that . © 1996 John Wiley & Sons, Inc.