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Titolo:
SYNTHESIS OF NOVEL HETEROQUATERPHENOQUINONES AND THEIR ELECTROCHEMICAL, STRUCTURAL, AND SPECTROSCOPIC CHARACTERIZATION
Autore:
TAKAHASHI K; GUNJI A; YANAGI K; MIKI M;
Indirizzi:
TOHOKU UNIV,DEPT CHEM,GRAD SCH SCI SENDAI MIYAGI 98077 JAPAN SUMITOMO CHEM CO LTD,BIOTECHNOL LAB TAKARAZUKA HYOGO 665 JAPAN
Titolo Testata:
Journal of organic chemistry
fascicolo: 14, volume: 61, anno: 1996,
pagine: 4784 - 4792
SICI:
0022-3263(1996)61:14<4784:SONHAT>2.0.ZU;2-P
Fonte:
ISI
Lingua:
ENG
Soggetto:
CROSS-CONJUGATED HYDROCARBONS; PARA-QUINONOID RING; TERPHENOQUINONE ANALOGS; SYSTEM; CHEMISTRY; COMPLEXES; DESIGN; BEARING; DYES;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
49
Recensione:
Indirizzi per estratti:
Citazione:
K. Takahashi et al., "SYNTHESIS OF NOVEL HETEROQUATERPHENOQUINONES AND THEIR ELECTROCHEMICAL, STRUCTURAL, AND SPECTROSCOPIC CHARACTERIZATION", Journal of organic chemistry, 61(14), 1996, pp. 4784-4792

Abstract

Novel heteroquaterphenoquinones, clohexadien-1-ylidene)-5,5'-dihydro-2,2'-bithienyl (3) and its 2,2'-biselenienyl (4), 2,2'-bifuryl (5), and 2,2'-bi-N-methylpyrrolyl (6) analogues, were synthesized by a stepwise cross-coupling reaction or by a more convenient one-pot oxidative homocoupling reaction of heterocycle-substituted phenols. Despite a highly conjugation-extended system, the quinones 3-6 are very stable in the solid state and in solution in common organic solvents. These quinones undergo a reversible one-stage, two-electron reduction up to dianions and a two-stage, one-electron oxidation reaction up to dications. The E(1)(rcd) of these quinones increases with the increase in the aromaticity of the incorporated heterocycles. The E(1)(ox) of these quinones appears to be specified by the ionization potential of the incorporated heterocycles. Thus, the N-methylquinone 6 exhibiting the lowest E(1)(ox) value exhibits the smallest E(1)(sum) among the quinones 3-6. The quinone 5 was revealed to exist in an unusual O-cis conformation in the solid state by X-ray crystallography, whereas the quinone 3 exists in an S-trans conformation in the solid state. The cis and trans isomers are interconvertible in solution in 3-5, whereas only N-trans isomer was detected for 6 in H-1 NMR spectroscopy. The quinones 3-6 exhibit a very intense absorption maximum in the near-infrared region of 662-827 nm. Of these, the maximum absorption wave length of 6 shifts to a more bathochromic region by 149-165 nm than those of 3-5. The quinones 3-6 can be used as dyestuffs in various fields for laser-driven high-density optical storage media.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 26/09/20 alle ore 05:22:01