Rotaxane

rotaxane

[rō′tak‚sān] (organic chemistry) A compound with two or more independent portions not bonded to each other but linked by a linear portion threaded through a ring and maintained in this position by bulky end groups.

Rotaxane

any of a group of chemical compounds composed of a linear molecular chain passing through a chainlike molecular ring. The compound is so arranged that the bulky end groups of the linear chain prevent the ring from slipping off.

Figure 1

The structural representation of a rotaxane molecule is shown in Figure 1, where R and R’ are radicals and the ring is a cyclic macromolecule.

The simplest type of rotaxane structure is shown in Figure 2, where η = 25–29. (This type of linear molecule will not fit within a smaller ring, that is, where η < 25; where n > 29, the stability of the rotaxane molecule is limited and the ring slips off the linear molecule.) The entities that form rotaxanes, that is, the linear and cyclic molecules, are bonded mechanically rather than chemically in what is called a topological bond.

Figure 2

Chemical compounds with topological bonding also include catenanes, wherein the cyclic macromolecules are joined in a fashion suggesting chain links. Figure 3 shows the structure of one of the synthesized catenanes. Rotaxanes and catenanes are obtained either by random formation in accordance with statistical laws (statistical synthesis) or by directed synthesis. The first statistical synthesis of rotaxanes was carried out by I. Harrison and S. Harrison (1967, United States); directed synthesis was first achieved by G. Schill and H. Zollenkopf (1969,

Figure 3

Federal Republic of Germany). Molecules of compounds constructed without chemical bonds occur in both organic and inorganic nature. Rotaxane and catenane forms of deoxyribonucleic acid (DNA) have been discovered.

REFERENCES

Schill, G., E. Logemann, and W. Vetter. “Ozonolytischer Abbau eines Catensins” Augewandte Chemie, 1972, vol. 84, no. 23, p. 1144.
Schill, G. Katenany, rotaksany i uzly. Moscow, 1973. (Translated from English.)
Kostianovskii, R. G. Katenany iklatraty. Moscow, 1966.

R. G. KOSTIANOVSKII

单词	rotaxane
释义	rotaxane ro·tax·ane R5342250 (rə-tăk′sān′, rō-)n. A complex molecule containing one or more macrocyclic ring components encircling a rodlike component that has end groups large enough to prevent the molecule from dissociating into its component parts. [Latin rota, wheel; see ret- in Indo-European roots + Latin axis, axle + -ane.] Rotaxane rotaxane [rō′tak‚sān] (organic chemistry) A compound with two or more independent portions not bonded to each other but linked by a linear portion threaded through a ring and maintained in this position by bulky end groups. Rotaxane any of a group of chemical compounds composed of a linear molecular chain passing through a chainlike molecular ring. The compound is so arranged that the bulky end groups of the linear chain prevent the ring from slipping off. Figure 1 The structural representation of a rotaxane molecule is shown in Figure 1, where R and R’ are radicals and the ring is a cyclic macromolecule. The simplest type of rotaxane structure is shown in Figure 2, where η = 25–29. (This type of linear molecule will not fit within a smaller ring, that is, where η < 25; where n > 29, the stability of the rotaxane molecule is limited and the ring slips off the linear molecule.) The entities that form rotaxanes, that is, the linear and cyclic molecules, are bonded mechanically rather than chemically in what is called a topological bond. Figure 2 Chemical compounds with topological bonding also include catenanes, wherein the cyclic macromolecules are joined in a fashion suggesting chain links. Figure 3 shows the structure of one of the synthesized catenanes. Rotaxanes and catenanes are obtained either by random formation in accordance with statistical laws (statistical synthesis) or by directed synthesis. The first statistical synthesis of rotaxanes was carried out by I. Harrison and S. Harrison (1967, United States); directed synthesis was first achieved by G. Schill and H. Zollenkopf (1969, Figure 3 Federal Republic of Germany). Molecules of compounds constructed without chemical bonds occur in both organic and inorganic nature. Rotaxane and catenane forms of deoxyribonucleic acid (DNA) have been discovered. REFERENCES Schill, G., E. Logemann, and W. Vetter. “Ozonolytischer Abbau eines Catensins” Augewandte Chemie, 1972, vol. 84, no. 23, p. 1144. Schill, G. Katenany, rotaksany i uzly. Moscow, 1973. (Translated from English.) Kostianovskii, R. G. Katenany iklatraty. Moscow, 1966. R. G. KOSTIANOVSKII
随便看	graced someone with graced something with graced them with graced us with graced with graced with it graced with (something) graced with something graced you with grace ethel cecile rosalie allen grace evangelical free church grace factory farm project grace fellowship baptist church grace fellowship church grace fellowship community church graceful graceful as a swan graceful degradation graceful degradation of care graceful exit gracefully gracefully degradable multi-computer system gracefulness graceful restart graceful routing engine switchover

rotaxane

ro·tax·ane

Rotaxane

rotaxane

Rotaxane

REFERENCES