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Titolo:
SYNTHESIS AND CHARACTERIZATION OF 11,11,12,12-TETRACYANO-1,4-ANTHRAQUINODIMETHANES (1,4-TCAQS) - NOVEL ELECTRON ACCEPTERS WITH PHOTOINDUCEDCHARGE-TRANSFER PROPERTIES
Autore:
MARTIN N; SEGURA JL; SEOANE C; DELACRUZ P; LANGA F; ORTI E; VIRUELA PM; VIRUELA R;
Indirizzi:
UNIV COMPLUTENSE MADRID,FAC QUIM,DEPT QUIM ORGAN E-28040 MADRID SPAIN UNIV CASTILLA LA MANCHA,FAC QUIM,DEPT QUIM INORGAN ORGAN & BIOQUIM E-45001 TOLEDO SPAIN UNIV VALENCIA,DEPT QUIM FIS E-46100 BURJASSOT SPAIN
Titolo Testata:
Journal of organic chemistry
fascicolo: 13, volume: 60, anno: 1995,
pagine: 4077 - 4084
SICI:
0022-3263(1995)60:13<4077:SACO1>2.0.ZU;2-8
Fonte:
ISI
Lingua:
ENG
Soggetto:
EFFECTIVE HAMILTONIAN TECHNIQUE; N; ELECTROCHEMICAL PROPERTIES; TCNQ DERIVATIVES; SEMIEMPIRICAL METHODS; TRANSFER COMPLEXES; RADICAL-ANIONS; ORGANIC METALS; A MATERIALS; MOLECULES;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
69
Recensione:
Indirizzi per estratti:
Citazione:
N. Martin et al., "SYNTHESIS AND CHARACTERIZATION OF 11,11,12,12-TETRACYANO-1,4-ANTHRAQUINODIMETHANES (1,4-TCAQS) - NOVEL ELECTRON ACCEPTERS WITH PHOTOINDUCEDCHARGE-TRANSFER PROPERTIES", Journal of organic chemistry, 60(13), 1995, pp. 4077-4084

Abstract

The synthesis of novel substituted 11,11,12,12-tetracyano-1,4-anthraquinodimethanes (1,4-TCAQs) 3 from the corresponding 1,4-anthraquinones2 by reaction with the Lehnert's reagent is described, thus confirming the validity of this procedure to obtain different substitution patterns on the benzene fused quinone ring. W-vis spectra of the novel compounds show the presence of an intramolecular charge-transfer band in the blue part of the visible region. Depending upon the substitution pattern, the cyclic voltammetry (CV) measurements on 1,4-TCAQs reveal one reduction wave involving two electrons to the dianion or two One-electron reduction waves to the corresponding radical-anion and dianion. Acceptor properties similar to those of TCNQ are expected for 3 when the TCNQ moiety is substituted with chlorine atoms. The molecular and electronic structures of compounds 2 and 3 are investigated using the semiempirical PM3 method and the nonempirical VEH approach, respectively. PM3 calculations predict that 1,4-TCAQs are nonplanar and adopt a butterfly-type structure where the planarity of the lateral naphthalene unit is preserved. VEH calculations show that the naphthalene moietybehaves as an electron donor since the HOMO --> LUMO transition corresponds to an electronic charge transfer from this moiety to the acceptor TCNQ ring, thus supporting the experimental UV-vis results. The evolution of the geometric structure of compounds 3 upon reduction evidences a gain of aromaticity of the TCNQ ring, even if the anions are predicted to remain nonplanar. This absence of planarity justifies the low stability found experimentally for the anions and explains the observation of only one reduction wave involving two-electrons for the mosthindered derivatives.

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Documento generato il 04/12/20 alle ore 16:46:30