Search results for "Exchange"
showing 10 items of 2035 documents
Meson exchange currents in pion double charge exchange at high energies
1995
In this letter we study the high energy behavior of the forward differential cross section for the $^{18}O(\pi^+,\pi^-)^{18}Ne$ double charge exchange reaction. We have evaluated the sequential and the meson exchange current mechanisms. The meson exchange current contribution shows a very weak energy dependence and becomes relevant at incident pion kinetic energies above 600 MeV.
A rare case of solution and solid state inter-conversion of two copper(II) dimers and a copper(II) chain
2011
Abstract Three Cu(II)-azido complexes of formula [Cu2L2(N3)2] (1), [Cu2L2(N3)2]·H2O (2) and [CuL(N3)]n (3) have been synthesized using the same tridentate Schiff base ligand HL (2-[(3-methylaminopropylimino)-methyl]-phenol), the condensation product of N-methyl-1,3-propanediamine and salicyldehyde). Compounds 1 and 2 are basal-apical μ-1,1 double azido bridged dimers. The dimeric structure of 1 is centrosymmetric but that of 2 is non-centrommetric. Compound 3 is a μ-1,1 single azido bridged 1D chain. The three complexes interconvert in solution and can be obtained in pure form by carefully controlling the synthetic conditions. Compound 2 undergoes an irreversible transformation to 1 upon de…
1,2,4-Triazole Schiff base directed synthesis of polynuclear iron complexes: Investigating the magnetic properties going from a dimer to a 1D chain t…
2018
Abstract Based on two functionalized Schiff base ligands 4-(1H-imidazol-5-ylmethylene-amino)-4H-1,2,4-triazole (imztrz) and 4-(p-tolylidene-amino)-4H-1,2,4-triazole (toltrz), a series of three triazole based polynuclear Fe complexes has been prepared. Compounds {[FeII(toltrz)2(C2O4)]·10H2O}n (1) and {[FeII(5-imztrz)(C2O4)]·2H2O}n (2) are oxalate bridged FeII complexes with 1 showing a linear 1D chain structure and 2 exhibiting a zigzag chain based 3D interpenetrating framework. Both structures show rather big voids in the 3D architecture (∼15% of the crystal volume). Compound (5-imztrzH)2[FeIII2(cit4−)2(H2O)2]·6H2O (3) is a binuclear FeIII complex bridging by two citrate ligands to form a f…
Synthesis, structure and magnetic characterization of a dinuclear and two mononuclear iron(III) complexes with N,O-donor Schiff base ligands
2018
Abstract One centrosymmetric dinuclear and two mononuclear iron(III) Schiff base complexes, [(µ-OMe)2Fe2(L1)2(N3)2] (1) {HL1 = 2-((2-(dimethylamino)ethylimino)methyl)-6-ethoxyphenol}, [FeL2(OH2)(N3)]·CH3OH (2) {H2L2 = N,N′-bis(3-ethoxysalicylidene)propane-1,3-diamine} and [FeL3(OH2)(NCS)]·2H2O (3) {H2L3 = N,N′-bis(3-methoxysalicylidene)propane-1,3-diamine}, have been synthesized and characterized by elemental analysis and spectral studies. X-ray diffraction analysis was used to determine the structures of all three complexes. Variable temperature (2–300 K) magnetic susceptibility (χ) data of complex 1 show that both iron(III) centres in the complex are in a high spin configuration (S = 5/2)…
One dimensional Mn(III) Schiff-base complex organization through very strong symmetrical H-bond interaction
2016
Abstract We are reporting the structural and magnetic characterization of a Mn(III) mononuclear complex based on a Schiff-base ligand with carboxylate pendant arm. Very strong symmetric H-interaction drives a one dimensional organization of this complex, densely packed through C–H⋯π further interactions. Low temperature magnetic behaviour appears governed by local ion zero field splitting obscuring any possible weak exchange interaction through the symmetric H-bond pathway.
Mononuclear Mn(III) and dinuclear Mn(III,III) Schiff base complexes: Influence of π–π stacking on magnetic properties
2012
Abstract Synthesis of a mononuclear Mn(III) (1) and a dinuclear Mn(III, III) (2) complex of a tetradentate N2O2 donor Schiff base ligand with ancillary carboxylate ligands are reported. Complex 1 crystallizes in the monoclinic space group C2/c, complex 2 in the triclinic space group P-1. In both complexes the central Mn(III) ions are hexacoordinated having a distorted octahedral MnN2O4 coordination environment. Intermolecular hydrogen bonding and strong π–π stacking in both 1 and 2 leads to dimerization of 1 and formation of a syn–anti one-dimensional chain for 2. Magnetic properties of 1 and 2 are reported. Both complexes show very weak intermolecular antiferromagnetic interaction. Most in…
An original 1D Cu–Co heterometallic compound: synthesis, structure and magnetic properties
2006
A novel heterobimetallic system, 1∞[LCuIICoII(NCS)2] (1), was obtained by reacting the neutral mononuclear complex [LCu] with cobalt(II) acetate in the presence of potassium thiocyanate (L is the dianion of the Schiff base resulting from the 2 ∶ 1 condensation of 3-methoxysalicylaldehyde with 1,3-propanediamine). The crystallographic investigation of 1 reveals a one-dimensional alternating zig-zag chain-like structure, made of dinuclear {LCuCo} units linked by thiocyanate bridges. The copper(II) ion is pentacoordinate to the N2O2 donor set of the Schiff base ligand in the basal plane, with the apical position occupied by the sulfur atom. The cobalt ion displays a strongly distorted (4 + 2) …
Energy Performance and Indoor Comfort of a 1930s Italian School Building: A case study
2021
Reducing energy consumption in the building tertiary sector, which accounts for a big share of the total energy use (and related CO 2 emissions) at European and Italian level, represent a strong element of safety for the EU-28. On the other hand, it is important to improve the, often overlooked, indoor comfort conditions of Italian schools since they have a significant impact on the well-being, productivity, health and safety of their occupants. Thus, it is appropriate to take into account the combination of both needs, also in light of the climate change scenario, in order to identify adequate improvement measures and justify such economic investment. This paper brings a contribution to th…
Data on physical and chemical characterization of wood combustion products derived at cogeneration power plants
2021
The data presented in this article are related to the research paper “Granulation of fly ash and biochar with organic lake sediments – A way to sustainable utilization of waste from bioenergy production” [1] in the context of waste material investigation and possible valorization instead of disposal. This article provides a comprehensive chemical and physical characterization of wood combustion products – fly ashes, bottom ashes, mixed ashes and biochar. Multiple analytical techniques and methodology were exploited to investigate the composition of wood combustion products, among them a loss on ignition, potentiometry, colorimetry, X-ray diffractometry, X-ray fluorescence spectrometry, indu…
Knowledge exchange through science diplomacy to assist disaster risk reduction
2021
Abstract This paper analyses science diplomacy efforts to reduce disaster risks and proposes establishing national knowledge exchange centers (KECs) to help individual states adhere to their Sendai Framework goals. KECs are considered to be interconnected globally and work together to promote resilience efforts by facilitating sharing of information and strategies in risk monitoring, assessment, and ultimately reduction across the globe. KECs can provide high-quality scientific evidence for informed decisionmaking along with a component related to disaster science media to ensure that appropriate knowledge reaches a variety of people who need it in different forms tailored for them. KECs ca…