Microwave assisted organic synthesis-a review

Functionalized acenes and heteroacenes for organic electronics.

"United we stand, divided we fall."--Aesop. Aggregation-induced emission (AIE) refers to a photophysical phenomenon shown by a group of luminogenic materials that are non-emissive when they are dissolved in good solvents as molecules but become highly luminescent when they are clustered in poor solvents or solid state as aggregates. In this Review we summarize the recent progresses made in the area of AIE research. We conduct mechanistic analyses of the AIE processes, unify the restriction of intramolecular motions (RIM) as the main cause for the AIE effects, and derive RIM-based molecular engineering strategies for the design of new AIE luminogens (AIEgens). Typical examples of the newly developed AIEgens and their high-tech applications as optoelectronic materials, chemical sensors and biomedical probes are presented and discussed.

Aggregation-Induced Emission: The Whole Is More Brilliant than the Parts

With advances in exfoliation and synthetic techniques, atomically thin films of semiconducting transition metal dichalcogenides have recently been isolated and characterized. Their two-dimensional structure, coupled with a direct band gap in the visible portion of the electromagnetic spectrum, suggests suitability for digital electronics and optoelectronics. Toward that end, several classes of high-performance devices have been reported along with significant progress in understanding their physical properties. Here, we present a review of the architecture, operating principles, and physics of electronic and optoelectronic devices based on ultrathin transition metal dichalcogenide semiconductors. By critically assessing and comparing the performance of these devices with competing technologies, the merits and shortcomings of this emerging class of electronic materials are identified, thereby providing a roadmap for future development.

Emerging Device Applications for Semiconducting Two-Dimensional Transition Metal Dichalcogenides

: The unpolarized absorption and circular dichroism spectra of the fundamental vibrational transitions of the chiral molecule, 4-methyl-2-oxetanone, are calculated ab initio. Harmonic force fields are obtained using Density Functional Theory (DFT), MP2, and SCF methodologies and a 5S4P2D/3S2P (TZ2P) basis set. DFT calculations use the Local Spin Density Approximation (LSDA), BLYP, and Becke3LYP (B3LYP) density functionals. Mid-IR spectra predicted using LSDA, BLYP, and B3LYP force fields are of significantly different quality, the B3LYP force field yielding spectra in clearly superior, and overall excellent, agreement with experiment. The MP2 force field yields spectra in slightly worse agreement with experiment than the B3LYP force field. The SCF force field yields spectra in poor agreement with experiment.The basis set dependence of B3LYP force fields is also explored: the 6-31G* and TZ2P basis sets give very similar results while the 3-21G basis set yields spectra in substantially worse agreements with experiment. jg

Ab initio calculation of vibrational absorption and circular dichroism spectra using density functional force fields

A partir de l'amino-7 phenyl-9 oxa-8 spiro [4.5] decadiene-6,9 (I), obtention de l'amide de l'acide dicyano-1,3 phenyl-2 spiro [3.4] octene-2 carboxylique-1, du benzenepropiolonitrile et de l'amide de l'acide cyclopentylidene-2 nitrolo-3 propionique. A partir d'autres derives de (I) on obtient principalement du benzenepropiolonitrile

Synthesis of cyclobutenes by the novel photochemical ring contraction of 4-substituted 2-amino-3,5-dicyano-6-phenyl-4H-pyrans

The main types of cyano-containing electron acceptor molecules,
particularly those derived from TCNQ and DCNQI acceptors, have been
reviewed. Ring substitution, the presence of heteroatoms and
extendedπ-conjugation have been used as the principal
structural modifications on the acceptor framework. Recent examples of
C
 60
 based electron acceptors bearing an acceptor organic addend
and other single-component donor–acceptor systems exhibiting
semiconducting behaviour are also discussed.

Design and synthesis of TCNQ and DCNQI type electron acceptor molecules as precursors for 'organic metals'

Novel π-conjugated donor−acceptor chromophores, based on the strong electron-donating tetrathiafulvalene moiety and different electron-withdrawing acceptors, exhibit large second-order optical nonl...

Tetrathiafulvalene Derivatives as NLO-phores: Synthesis, Electrochemistry, Raman Spectroscopy, Theoretical Calculations, and NLO Properties of Novel TTF-Derived Donor-π-Acceptor Dyads

RECENT ADVANCES IN o-QUINODIMETHANE CHEMISTRY

A series of highly conjugated tetrathiafulvalene (TTF) analogues with a quinonoid structure has been synthesized, and their structural and electronic properties have been characterized by both experimental techniques and quantum-chemical calculations. Cyclic voltammetry measurements show a two-electron oxidation wave to form the dication, which is mainly located on the dithiole rings. The second irreversible oxidation wave to form the trication-radical corresponds to the oxidation of the polyacenic backbone. The temperature dependence of the reduction peak corresponding to the donor2+ → donor0 process is explained in terms of the low stability of the cation and the high aromaticity of the dication. Charge-transfer complexes are formed with the strong acceptor TCNQF4 showing a 1:2 (D:A) stoichiometry and a semiconducting behavior. The molecular structures of neutral and oxidized compounds are investigated by performing theoretical calculations at the semiempirical, ab initio, and density functional theory ...

Carlos Seoane

Papers

Synthesis of cyclobutenes by the novel photochemical ring contraction of 4-substituted 2-amino-3,5-dicyano-6-phenyl-4H-pyrans

Design and synthesis of TCNQ and DCNQI type electron acceptor molecules as precursors for 'organic metals'

Tetrathiafulvalene Derivatives as NLO-phores: Synthesis, Electrochemistry, Raman Spectroscopy, Theoretical Calculations, and NLO Properties of Novel TTF-Derived Donor-π-Acceptor Dyads

RECENT ADVANCES IN o-QUINODIMETHANE CHEMISTRY

Synthesis, Properties, and Theoretical Characterization of Largely π-Extended Tetrathiafulvalene Derivatives with Quinonoid Structures