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Carbon rings, ring strain

In the main, the physical and chemical properties of saturated and partially unsaturated alicyclic compounds closely resemble those of the analogous acyclic compounds formally derived by cleavage of the carbon ring at a point remote from any functionality. Relatively small, but often significant, differences in properties arise from conformational effects, and from strain effects in small rings, and these differences can be striking in properties which are particularly sensitive to molecular shape. [Pg.2]

All of the carbon atoms in buckminster-fullerene are equivalent and are sp -hybridized each one simultaneously belongs to one five-membered ring and two benzene-like six-membered rings. The strain caused by distortion of the rings from coplanarity is equally distributed among all of the carbons. [Pg.436]

Woker attempts to apply this strain theory to ring compounds, and considers that the five carbon atom ring produces less strongly odoured substances than any other and points out that, according to Baeyer s strain theory, the five carbon ring has the least internal tension. It is very doubtful if this contention is correct, since the penta-methylenes do not seem to be less strongly odoured than other polymethylene ring compounds. ... [Pg.30]

There is an interesting tendency of the ring strains of the large cage molecules. Persiladodecahedrane Sij Hj (SE = 32.3 kcal mol ) is less strained than the carbon congener, dodecahedron (SE = 43.6 kcal mol ) [76, 77]. Low strain of silicon congener is more apparent for persilafulleran (SE =114 kcal... [Pg.284]

According to Baeyer, the first member of the series of strained carbon hydride ring compounds is ethylene (n=2). Our last basic statement connects ring strain with ir-bond strength. [Pg.85]

Fig. 3. Calculated ring strain energies per strained angle in silicon and carbon ring compounds using the homodesmotic reaction. The angle a is half of the deviation of the angle between the straight atomic connection lines from the unstrained angle (109.47 deg). Fig. 3. Calculated ring strain energies per strained angle in silicon and carbon ring compounds using the homodesmotic reaction. The angle a is half of the deviation of the angle between the straight atomic connection lines from the unstrained angle (109.47 deg).
The coordinated macrocycle readily reacts with alkoxide ions to yield products of type (71) (Taylor, Urbach Busch, 1969). In so doing additional flexibility is imparted to the ring which may reduce ring strain and, in part, provide a driving force for the reaction. Thus the coordinated imine carbons appear predisposed to attack by such nucleophiles. Based on this knowledge, elegant template syntheses of three-dimensional derivatives have been performed. The syntheses involved the reaction of [M(taab)]2+ (M = Ni, Cu) with the dialkoxide ions derived from bis(2-hydroxyethyl)sulphide or bis(2-hydroxyethyl)methylamine (Katovic, Taylor Busch, 1969). The products were demonstrated to be monomeric square-pyramidal complexes of type (72). The condensation... [Pg.35]

Both electrophilic and nucleophilic reagents are able to cleave the ring in cyclic germanium-carbon compounds due to the ring strain and the polarizability of the germanium-carbon bond, as illustrated in Figure 748,49. [Pg.549]


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See also in sourсe #XX -- [ Pg.8 , Pg.8 ]




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Ring Carbon

Ring strain

Strained rings

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