Carlos Seoane

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

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.

Semiconducting charge transfer complexes from [60]Fullerene-tetrathiafulvalene (C60-TTF) systems

Abstract The first CT-complexes of covalently bound [60]Fullerene-tetrathiafulvalene (TTF) systems with tetrafluorotetracyano-p-quinodimethane (TCNQF 4 ) show a semiconducting behaviour.

The first tetrathiafulvalene derivatives exhibiting second-order NLO properties

Abstract The second order NLO properties of push-pull TTF derivatives have been studied for the first time. The effect of modifying both the acceptor and the donor moieties on the μβ values has been studied by experimental (EFISH) and theoretical techniques.

The first asymmetric synthesis of polyfunctionalized 4H-pyrans via Michael addition of malononitrile to 2-acyl acrylates

Abstract Starting from (R)-2,3-O-isopropylideneglyceraldehyde, the first asymmetric synthesis of 4H-pyrans ( 4 ) has been developed; a detailed X-ray structural and stereochemical study has established as R the absolute configuration at the new stereocenter in compounds 4 .

X-Ray and theoretical structural study of novel 5,6,7,8-tetrahydrobenzo-4H-pyrans

Abstract The X-ray crystal structure of three substituted tetrahydrobenzo-4H-pyrans ( 6a–c ) is presented and the experimental findings compared with the theoretical values calculated at the semiempirical (AM1, PM3) and ab initio (HF/6-31G∗) levels. A good agreement between both experimental and theoretical data is found showing a flattened boat conformation for the 4H-pyran ring and a pseudo-axial orientation of the aryl ring on the C4 position. The geometrical features of these systems ( 6a–c ) reveal that they present the structural requirements to act as calcium antagonists.

The first two decades of a versatile electron acceptor building block: 11,11,12,12-tetracyano-9,10-anthraquinodimethane (TCAQ)

This critical review surveys the development of the structural and electrochemical knowledge of the TCAQ moiety since its discovery, nearly two decades ago, until the present. Additionally, recent advances in the chemistry and functionalization of this versatile building block are highlighted, with special emphasis on the strategies devoted to the preparation of donor-acceptor molecular and polymeric materials. The applications of TCAQ-based materials in materials science as electrical conductors, molecular rectifiers, in photoinduced electron transfer processes, optoelectronic devices and as electrochiroptical materials are also reviewed (89 references).

Development of methods for the synthesis of chiral, highly functionalized 2-amino-4-aryl-4H-pyrans

The development of new methods for the asymmetric synthesis of highly functionalized 2-amino-4-aryl-4 H -pyrans is described. Two alternative synthetic routes: the 1,4-conjugate addition of chiral β-ketoesters 3 or the N -acetoacetyl sultam 11 to arylidenemalononitriles 6 , and the Michael addition of malononitrile to enantiomerically pure α-acetylcinnamates 5 , have been designed. Depending upon the chiral auxiliary, the resulting 4 H -pyrans were obtained in low [(−)-menthol, (−)-borneol, (−)-ethyl lactate] to good (Oppolzers sultam) diastereomeric excesses. The absolute configuration at the new stereocenter in the minor isomer of compound 12a was determined as S by X-ray diffraction analysis. Reductive cleavage of 4 H -pyrans 12 with lithium aluminiun hydride yielded the enantiomerically pure or enriched alcohols 14 .

Second-order nonlinear optical properties of tetrathiafulvalene-π-3-(dicyanomethylidene)indan-1-one chromophores

Novel conjugated donor-acceptor chromophores, based on the strong electron donating tetrathiafulvalene moiety and the strong electron-withdrawing 3-(dicyanomethylidene)indan-1-one acceptor, exhibit large second-order optical nonlinearities. The effect of increasing the length of the polyenic spacer on the NLO properties of the new molecules has been studied by using the electric field-induced second harmonic generation (EFISH) method.

New TTF-based donor-acceptor molecules linked by flexible ethylenic spacers

Novel TTF containing donor-spacer-acceptor molecules have been synthesized and their redox potentials determined by CV measurements. Second-order optical nonlinearities have been observed for the first time with the TTF unit as the donor moiety.

A Facile Formation of Electroactive Fullerene Adducts from Sultines via a Diels-Alder Reaction.

Abstract A new procedure for the functionalization of C 60 by microwave assisted Diels-Alder reaction with “sultines” is described: an accelerating microwave effect is observed; the electrochemical measurements reveal three reduction waves cathodically shifted compared to C 60