Novel metallophthalocyanines bearing 3-(p-chlorophenyl)-5-p-tolyl-4H-1,2,4-triazole bulky substituents by microwave irradiation

The synthesis of metallophthalocyanines [6–9; M = Ni(II), Zn(II), Co(II) and Cu(II)] with four 1,2,4-triazole units obtained from 4-{(4-chloro-2-fluorobenzyl)[3-(4-chlorophenyl)-5-(4-methylphenyl)-4H-1,2,4-triazol-4-yl]amino}phthalonitrile (5) in the presence of dimethylaminoethanol and the corresponding anhydrous metal salts is described. The thermal stabilities of the Pc compounds were determined by thermogravimetric analysis. The new compounds were characterized by a combination of IR, ¹H NMR, ¹³C NMR, UV–Vis, elemental analysis.     

Influence of the bridging ligand on the substitution behaviour of dinuclear Pt(II) complexes. An experimental and theoretical approach

A series of dinuclear Pt(II) complexes of the type [Pt2(N,N,N',N'-tetrakis(2-pyridylmethyl)diamine(H2O)2]4+ were synthesized. Acid-base titrations, and concentration and temperature dependent stopped-flow measurements of the reaction with chloride were performed to study the thermodynamic and kinetic behaviour of the dinuclear bridged complexes. The results indicate that there is a clear interaction between the two Pt(II) centres, which becomes weaker as the aliphatic chain increases in length. From a certain chain length onwards, the Pt(II) centres become independent of each other and exhibit identical thermodynamic and kinetic properties. The experimental results are discussed in reference to structures obtained by DFT (BP86/LACVP*) calculations.     

Some Remarks on Exp-Function Method and Its Applications-A Supplement

Recently, the authors of [Commun. Theor. Phys. 56 (2011) 397] made a number of useful observations on Exp-function method. In this study, we focus on another vital issue, namely, the misleading results of double Exp-function method.     

X-ray and Theoretical Studies of 2-((5-Amino-1,3,4-thiadiazol-2-yl)thio)-1-phenylethanone

The crystal structure of 2-((5-amino-1,3,4-thiadiazol-2-yl)thio)-1-phenylethanone was determined by X-ray diffraction method. The compound crystallizes in orthorhombic crystal system, sp. gr. Pbca. The atoms that constitute thiadiazole and phenyl rings do not form any significant deviation from the ring planes. Compound has two intermolecular N–H···N hydrogen bonds and one C–H···π interaction. Using DFT/B3LYP method with 6-31G(d), 6-311G(d), 6-311G(d, p), and 6-311++G(d, p) basis sets, the molecular geometry of the compound was optimised. Bond lenghts, bond angles, torsion angles, dihedral angles, and HOMO–LUMO were calculated from the optimised geometry of the compound. The results obtained by X-ray diffraction method were compared with the results obtained through four different basis sets. Total energy of the molecule was calculated for four different basis sets.     

Traveling Wave Solutions for Nonlinear Differential-Difference Equations of Rational Types

Differential-difference equations are considered to be hybrid systems because the spatial variable n is discrete while the time t is usually kept continuous.Although a considerable amount of research has been carried out in the field of nonlinear differential-difference equations,the majority of the results deal with polynomial types.Limited research has been reported regarding such equations of rational type.In this paper we present an adaptation of the(G /G)-expansion method to solve nonlinear rational differential-difference equations.The procedure is demonstrated using two distinct equations.Our approach allows one to construct three types of exact traveling wave solutions(hyperbolic,trigonometric,and rational) by means of the simplified form of the auxiliary equation method with reduced parameters.Our analysis leads to analytic solutions in terms of topological solitons and singular periodic functions as well.     

Decay property of Timoshenko system in thermoelasticity

We investigate the decay property of a Timoshenko system of thermoelasticity in the whole space for both Fourier and Cattaneo laws of heat conduction. We point out that although the paradox of infinite propagation speed inherent in the Fourier law is removed by changing to the Cattaneo law, the latter always leads to a solution with the decay property of the regularity‐loss type. The main tool used to prove our results is the energy method in the Fourier space together with some integral estimates. We derive L² decay estimates of solutions and observe that for the Fourier law the decay structure of solutions is of the regularity‐loss type if the wave speeds of the first and the second equations in the system are different. For the Cattaneo law, decay property of the regularity‐loss type occurs no matter what the wave speeds are. In addition, by restricting the initial data to with a suitably large s and γ ∈ [0,1], we can derive faster decay estimates with the decay rate improvement by a factor of t^?γ/2. Copyright © 2011 John Wiley & Sons, Ltd.     

Matching of the propagation constants in an asymmetric single-mode fused fiber coupler for core pumping thulium-doped fiber at 795 nm

We developed a fused fiber coupler (FFC) capable of multiplexing wavelengths in the range of 795 nm and 2 μm. A simple 2D simulation model to calculate the pretaper length for matching the propagation constants in the coupling region was established. Based on the numerical data, we fabricated an asymmetric FFC consisting of two different fibers with single-mode guidance for the respective wavelength, achieving a transmission of 90% in the signal fiber for both wavelengths. In order to demonstrate the application, we integrated the FFC into a core pumped thulium-doped fiber amplifier.     

Multiarm star block copolymers via Diels‐Alder click reaction

Two types of multiarm star block copolymers: (polystyrene)_m‐poly(divinylbenzene)‐poly(methyl methacrylate)_n, (PS)_m‐polyDVB‐(PMMA)_n and (polystyrene)_m‐poly(divinylbenzene)‐poly(tert‐butyl acrylate)_k, (PS)_m‐polyDVB‐(PtBA)_k were successfully prepared via a combination of cross‐linking and Diels–Alder click reactions based on “arm‐first” methodology. For this purpose, multiarm star polymer with anthracene functionality as reactive periphery groups was prepared by a cross‐linking reaction of divinyl benzene using α‐anthracene end functionalized polystyrene (PS‐Anth) as a macroinitiator. Thus, obtained multiarm star polymer was then reacted with furan protected maleimide‐end functionalized polymers: PMMA‐MI or PtBA‐MI at reflux temperature of toluene for 48 h resulting in the corresponding multiarm star block copolymers via Diels–Alder click reaction. The multiarm star and multiarm star block copolymers were characterized by using ¹H NMR, SEC, Viscotek triple detection SEC (TD‐SEC) and UV. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 178–187, 2009     

Star polymers with POSS via azide–alkyne click reaction

Azidopropyl‐heptaisobutyl‐substituted polyhedral oligomeric silsesquioxane (POSS‐N₃) was reacted with 1,1,1‐tris[4‐(2‐propynyloxy)phenyl]‐ethane ( 1 ) and poly(ethylene glycol) (PEG)‐b‐poly(methyl methacrylate) (PMMA) copolymer with alkyne at its center (PEG‐PMMA‐alkyne) affording the first time synthesis of 3‐arm star POSS and PEG‐PMMA‐POSS 3‐miktoarm star terpolymer, respectively, in the presence of CuBr/N,N,N′,N″,N″‐pentamethyldiethylenetriamine as catalyst and N,N‐dimethylformamide/tetrahydrofuran as solvent at room temperature. The precursors and the target star polymers were characterized comprehensively by ¹H NMR, GPC, and DSC. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5947–5953, 2009     

ROMP‐NMP‐ATRP combination for the preparation of 3‐miktoarm star terpolymer via click chemistry

A combination of ring opening metathesis polymerization (ROMP) and click chemistry approach is first time utilized in the preparation of 3‐miktoarm star terpolymer. The bromide end‐functionality of monotelechelic poly(N‐butyl oxanorbornene imide) (PNBONI‐Br) is first transformed to azide and then reacted with polystyrene‐b‐poly(methyl methacrylate) copolymer with alkyne at the junction point (PS‐b‐PMMA‐alkyne) via click chemistry strategy, producing PS‐PMMA‐PNBONI 3‐miktoarm star terpolymer. PNBONI‐Br was prepared by ROMP of N‐butyl oxanorbornene imide (NBONI) 1 in the presence of (Z)‐but‐2‐ene‐1,4‐diyl bis(2‐bromopropanoate) 2 as terminating agent. PS‐b‐PMMA‐alkyne copolymer was prepared successively via nitroxide‐mediated radical polymerization (NMP) of St and atom transfer radical polymerization (ATRP) of MMA. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 497–504, 2009