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Titolo:
SELF-ASSEMBLY OF NOVEL [2]CATENANES AND [2]PSEUDOROTAXANES INCORPORATING THIACROWN ETHERS OR THEIR ACYCLIC ANALOGS
Autore:
ASAKAWA M; ASHTON PR; DEHAEN W; LABBE G; MENZER S; NOUWEN J; RAYMO FM; STODDART JF; TOLLEY MS; TOPPET S; WHITE AJP; WILLIAMS DJ;
Indirizzi:
UNIV BIRMINGHAM,SCH CHEM,POB 363 BIRMINGHAM B15 2TT W MIDLANDS ENGLAND KATHOLIEKE UNIV LEUVEN,DEPT SCHEIKUNDE B-3001 HEVERLEE BELGIUM UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED,DEPT CHEM LONDON SW7 2AY ENGLAND
Titolo Testata:
Chemistry
fascicolo: 5, volume: 3, anno: 1997,
pagine: 772 - 787
SICI:
0947-6539(1997)3:5<772:SON[A[>2.0.ZU;2-U
Fonte:
ISI
Lingua:
ENG
Soggetto:
CROWN THIOETHER CHEMISTRY; MOLECULAR MECCANO; TRANSLATIONAL ISOMERISM; COMPLEXATION; CATENANDS; PARAQUAT; DESIGN;
Keywords:
CATENANES; MOLECULAR DEVICES; PSEUDOROTAXANES; SELF-ASSEMBLY; TRANSLATIONAL ISOMERISM;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
49
Recensione:
Indirizzi per estratti:
Citazione:
M. Asakawa et al., "SELF-ASSEMBLY OF NOVEL [2]CATENANES AND [2]PSEUDOROTAXANES INCORPORATING THIACROWN ETHERS OR THEIR ACYCLIC ANALOGS", Chemistry, 3(5), 1997, pp. 772-787

Abstract

A series of pi electron rich macrocyclic polythioethers and their acyclic analogues have been synthesized in good yields. The association constants for the complexation of the pi electron deficient bis(hexafluorophosphate) bipyridinium-based salt, paraquat, by these macrocycles,as well as those for the complexation of corresponding acyclic compounds by the bipyridinium-based tetracationic cyclophane, cyclobis(paraquat-p-phenylene), are significantly low-er than those observed in the case of the ''all-oxygen'' analogues. Nonetheless, yields as high as 86% were recorded in the template-directed syntheses of [2]catenanes composed of cyclobis(paraquat-p-phenylene) and the macrocyclic polythioethers. Single-crystal X-ray crystallographic analyses of the [2]catenanes incorporating constitutionally unsymmetrical pi electron rich macrocyclic polythioethers revealed that, in all cases, the dioxyaromatic units are located inside the cavity of the tetracationic cyclophane component in preference to the dithiaaromatic units. A similar selectivity was observed in solution by variable-temperature H-1 NMR spectroscopy. However, inversion of the ratio between the two translational isomers of the two [2]catenanes bearing 1,5-dithianaphthalene, as one of their pi electron rich ring systems, and either 1,4-dioxybenzene or 1,5-dioxynaphthalene, as the other, occurs upon increasing the temperature from -30 to +30 degrees C. These [2]catenanes fan be viewed as temperature-responsive molecular snitches.

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Documento generato il 22/01/20 alle ore 18:54:40