Search results for " Salen"
showing 10 items of 15 documents
Phosphasalen group IV metal complexes: synthesis, characterization and ring opening polymerization of lactide.
2020
International audience; We report the synthesis of a series of Zr and Ti complexes bearing phosphasalen which differs from salen by the incorporation of two P atoms in the ligand backbone. The reaction of phosphasalen proligands (1a-1c)H2 with Zr(CH2Ph)4 led to different products depending on the nature of the N,N-linker in the ligand. In case of ethylene-linked phosphasalen, octahedral Zr complex 2a formed as a single stereoisomer in trans geometry. With the phenylene linker, it was shown by dynamic NMR spectroscopy that complex 2b exists as a mixture of trans and cis-β isomers in solution, both enantiomers (Δ and Λ) of the cis-β isomer being in fast equilibrium with respect to the NMR tim…
On the Existence of Different Zeolite-Associated Topological Redox Isomers. Electrochemistry of the Y Zeolite-Associated Mn(Salen)N3 Complex
2002
The electrochemical properties of Y zeolite-associated MnIII(salen)N3 (salen = trans-(R,R)-1,2-bis(salicyldeneamino)cyclohexane) has been investigated using polymer film electrodes immersed into neutral aqueous solutions. Zeolite Y-associated Mn(III)−salen complexes are reduced in one-electron reversible process at −0.25 V versus SCE. The electrochemical response is discussed in terms of the existence of two topological redox isomers: a weakly boundary-associated Mn(salen) complex, whose electrochemical response corresponds to a reversible one-electron transfer controlled by diffusion of the positive ions of the supporting electrolyte through the zeolite surface windows and channels, and a…
DFT computational study on Fe(III)-N,N′-ethylene-bis(salicylideneiminato) derivatives
2005
DFT calculations, at unrestricted B3LYP level, have been performed on the structures of three iron(III) complexes, Fe(Salen)Cl, [Fe(Salen)]+ and [Fe(Salen)OH2]+, where Salen is the anion of Schiff base ligand N,N′-ethylene-bis (salicylideneimine), considering the spin multiplicity (S) values 2, 4 and 6. The results obtained have been compared with the available structural an magnetic experimental data, allowing us to conclude that a stable form of the FeIII(Salen) complex in aqueous solution should be characterized by an energy stabilization of the S=4 compared to the S=6 state.
Rinascimento alla francese: Gabriele Licciardo, architettura e costruzione nel Salento della metà del Cinquecento
2015
L’architettura salentina del XVI secolo offre ricchezza e profondità di riferimenti ma anche ostacoli posti contestualmente da una documentazione incompleta e priva di riscontri sicuri. Di questa labilità di assunti è intrisa la vicenda della personalità che viene considerata risolutiva, quella più nota per la storiografia architettonica: Gabriele Licciardo. Questo studio parte da una ricostruzione plausibile della biografia del maestro alla luce delle poche notizie esistenti e dell’architettura costruita. Per individuare aspetti utili ad inquadrare il caso Licciardo occorre osservare fabbriche note del Salento e che sono accomunate da sperimentazioni significative nel campo delle volte in …
The interaction of native DNA with iron(III)- N ,N'-ethylene-bis(salicylideneiminato)-chloride.
2004
Abstract The interaction between native calf thymus deoxyribonucleic acid (DNA) and Fe III - N , N ′ -ethylene-bis (salicylideneiminato)-chloride, Fe(Salen)Cl, was investigated in aqueous solutions by UV–visible (UV–vis) absorption, circular dichroism (CD), thermal denaturation and viscosity measurements. The results obtained from CD, UV–vis and viscosity measurements exclude DNA intercalation and can be interpreted in terms of an electrostatic binding between the Fe(Salen) + cation and the phosphate groups of DNA. The trend of the UV–vis absorption band of the Fe(Salen)Cl complex at different ratios [DNA phosphate ]/[Fe(Salen)Cl] and the large increase of the melting temperature of DNA in …
A dinuclear rhodium(III) complex with the N,N′-ethylenebis(salicylideneiminato) (salen) ligand in a bridging bis-bidentate mode of coordination. Crys…
1990
In this communication we describe the synthesis and crystal structure of the complex [{Rh(η 2 -(C 6 H 4 )PPh 2 )(η 2 -P(o-ClC 6 H 4 )Ph 2 )} 2 (salen)]-(SbF 6 ) 2 , showing the bridging configuration of the salen ligand
Antonio Galateo fra Salento ed Europa, in Graeci sumus et hoc nobis gloriae accedit. In memoria di Amleto Pallara
2016
L'articolo è incentrato sulla figura del medico e scrittore quattrocentesco Antonio De Ferrariis detto Antonio Galateo.
'Graeci sumus et hoc nobis gloriae accedit'. La grecità salentina di Antonio Galateo
2020
L'esperienza intellettuale di Galateo rappresenta una svolta importante nelle vicende culturali che collegarono e divisero le coste adriatiche e ioniche della Puglia e della Grecia tra il XV e il XVI secolo. Galateo's intellettual experience is an important turning point in the cultural events that linked and divided the Adriatic and Ioanian coasts of Puglia and Greece between the XV and XVI century.
Tri-alkenyl polyhedral oligomeric silsesquioxanes as comonomers and active center modifiers in ethylene copolymerization catalyzed by bis(phenoxy-imi…
2018
Abstract In copolymerization of ethylene (E) with tri-alkenyl-silsesquioxanes (POSS-6-3 and POSS-10-3) were used bis(phenoxy-imine) titanium, zirconium and vanadium catalysts, as well as salen-type vanadium catalysts. There were obtained copolymers with POSS-R-3 units as side branches of polymer chains. The type of employed bis(phenoxy-imine) titanium, zirconium and vanadium catalysts and salen-type catalyst of vanadium determined the copolymer chain termination reactions, as well as the mechanism of modification of the active species by the POSS-R-3 comonomer. POSS-R-3 comonomers caused selective poisoning of bis(phenoxy-imine) zirconium catalyst and they provided protection against tight …