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Titolo:
TOWARD CONTROLLABLE MOLECULAR SHUTTLES
Autore:
ANELLI PL; ASAKAWA M; ASHTON PR; BISSELL RA; CLAVIER G; GORSKI R; KAIFER AE; LANGFORD SJ; MATTERSTEIG G; MENZER S; PHILP D; SLAWIN AMZ; SPENCER N; STODDART JF; TOLLEY MS; WILLIAMS DJ;
Indirizzi:
UNIV BIRMINGHAM,SCH CHEM,POB 363 BIRMINGHAM B15 2TT W MIDLANDS ENGLAND UNIV MIAMI,DEPT CHEM CORAL GABLES FL 33124 UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED,DEPT CHEM LONDON SW7 2AY ENGLAND BRACCO I-20134 MILAN ITALY
Titolo Testata:
Chemistry
fascicolo: 7, volume: 3, anno: 1997,
pagine: 1113 - 1135
SICI:
0947-6539(1997)3:7<1113:TCMS>2.0.ZU;2-W
Fonte:
ISI
Lingua:
ENG
Soggetto:
PHOTOINDUCED ELECTRON-TRANSFER; TEMPLATE-DIRECTED SYNTHESIS; ELECTROCHEMICAL PROPERTIES; POLY(ETHYLENE GLYCOL); ALPHA-CYCLODEXTRINS; INCLUSION COMPLEXES; RECOGNITION; RECEPTOR; ROTAXANE; CYCLOBIS(PARAQUAT-PARA-PHENYLENE);
Keywords:
MOLECULAR DEVICES; NANOSTRUCTURES; ROTAXANES; SELF-ASSEMBLY; TRANSLATIONAL ISOMERISM;
Tipo documento:
Review
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
128
Recensione:
Indirizzi per estratti:
Citazione:
P.L. Anelli et al., "TOWARD CONTROLLABLE MOLECULAR SHUTTLES", Chemistry, 3(7), 1997, pp. 1113-1135

Abstract

A number of nanometer-scale molecular assemblies, based on rotaxane-type structures, have been synthesized by means of a template-directed strategy from simple building blocks that, on account of the molecularrecognition arising from the noncovalent interactions between them, are able to self-assemble into potential molecular abacuses. In all thecases investigated, the pi-electron-deficient tetracationic cyclophane cyclobis(paraquat-p-phenylene) is constrained mechanically around a dumbbell-shaped component consisting of a linear polyether chain intercepted by at least two, if not three, K-electron-rich units and terminated at each end by blocking groups or stoppers. The development of anapproach toward constructing these molecular abacuses, in which the tetracationic cyclophane is able to shuttle back and forth with respectto the dumbbell-shaped component, begins with the self-assembly of a [2]rotaxane consisting of two hydroquinone rings symmetrically positioned within a polyether chain terminated by triisopropylsilyl ether blocking groups. In this first so-called molecular shuttle, the tetracationic cyclophane oscillates in a degenerate fashion between the two pi-electron-rich hydroquinone rings. Replacement of one of the hydroquinone rings-or the insertion of another pi-electron-rich ring system between the two hydroquinine rings-introduces the possibility of translational isomerism, a phenomenon that arises because of the different relative positions and populations of the tetracationic cyclophane with respect to the pi-donor sites on the dumbbell-shaped component. In two subsequent [2]rotaxanes, one of the hydroquinone rings in the dumbbell-shaped component is replaced, first by a p-xylyl and then by an indoleunit. Finally, a tetrathiafulvalene (TTF) unit is positioned between two hydroquinone rings in the dumbbell-shaped component. Spectroscopicand electrochemical investigations carried out on these first-generation molecular shuttles show that they could be developed as molecular switches.

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Documento generato il 18/01/20 alle ore 21:36:11