1,721,032 research outputs found
ZnII-porphyrinates with a dithienylethylene moiety linked in β-pyrrolic position by different π bridges: a panchromatic-dye approach to PSSCs
No full text
Metal-Induced Assembling/Disassembling of Fluorescent Naphthalenediimide Dericatives Signalled by Excimer Emission
Full text linkThe new quadridentate bis-chelating ligands 2 and 3 display in solution the typical absorption and emission properties expected for naphthalenediimide derivatives. Spectrophotometric studies show that systems 2 and 3 interact with ZnII, CdII and CuI in CHCl3 or MeCN solution according to an apparent 1:1 stoichiometry. Molecular modelling, ESI-MS and 1H-NMR experiments point out that the complex species formed in the presence of stoichiometric amounts of metal ion are non-helical [2+2] adducts. The metal induced self-assembling process is signalled by an intense excimer-type emission due to the intramolecular interaction of two naphthalenediimide subunits which face each other in the [2+2] adduct, as shown by molecular modelling studies. In the presence of excess metal ion, a disassembling process takes place, leading to a dinuclear complex with a 2:1 metal:ligand stoichiometry, in which the intramolecular excimer is no longer allowed to form, since the interaction between the naphthalenediimide subunits has been lost. Thus, the overall metal-induced assembling/disassembling process is signalled by the appearance and disappearance of the excimer band in the emission spectrum
Time-dependent and coupled-perturbed DFT and HF investigations on the absorption spectrum and non-linear optical properties of push-pull M(II)-porphyrin complexes (M= Zn, Cu, Ni)
No full textMetal-induced assembling/disassembling of naphthalenediimide derivatives signalled by excimer emission
No full textTetraarylcyclosiloxane rings as scaffolds for second order NLOactive and photoluminescent materials
No full textSynthesis and structural characterisation of functionalised cyclotetrasiloxane rings [4-RC6H4Si(O)OR’]4 (R= Cl, Br, CH=CH2, CH2Cl; R’= Na, SiMe3) as scaffolds for the synthesis of models of a silica bound monolayer of fluorescent or second order NLO active organic chromophores
No full textCustomised porphyrin coating films for graphite electrode protection: An investigation on the role of peripheral groups by coupled AFM and cyclic voltammetry techniques
No full textControlling the molecular arrangement of properly designed materials is the ultimate target of studies in surface protection by organic thin films. The properties of the films are even more critical when the protection ability must be match with the function of the underneath active surface as in the case of electrodes covered by suitable protective as well conductive materials. In this context, we demonstrate that the electrode protection against anion intercalation, exerted by a vacuum deposited thin film of meso-tetraphenylporphyrin (H2TPP) on a highly-oriented pyrolytic graphite (HOPG) electrode, can be maximized by tailoring the peripheral groups of the porphyrin skeleton. From atomic force microscopy and cyclic voltammetry investigations, our results highlight the important role played by the molecular/electronic structure of the porphyrins to enhance the molecule-substrate interaction and the molecular assembly in the case of a perfluorinated derivative, thus resulting in effective protection ability in acid environment outperforming theH2TPP film
Synthesis of novel push-pull β-substituted ZnII-porphyrinates by a microwave assisted sonogashira coupling approach
No full text- …
