Rate of inversion

Inventur, /. inventory stocktaking. Inversionageschwindigkeit, /. rate of inversion, invertieren, v.t. invert. 

Stereochemistry of the vinyl bromide is inconsequential due to the high rate of inversion of the intermediate vinyl radical... 

What was actually measured was the rate of racemization, which is twice the rate of inversion, since each inversion creates, in effect, two racemic molecules. The significance of this result is that it shows that every act of exchange is an act of inversion. 

If organotin molecules can be made which contain, besides the chiral tin atom, another asymmetric atom which is optically stable, then they can exist as two diastereomeric racemic mixtures if the other atom is not resolved, or as two diastereomers if the other atom is. If these two diastereomeric mixtures (or diastereomers) can be separated (or at least if two mixtures of different compositions, i.e. diastereomeric ratios, can be obtained), then the rate at which these two mixtures (or compounds) are transformed into the equilibrium mixture is a measure for the rate of inversion at the tin atom. 

Cane sugar is hydrolyzed by the action of yeast. The tabulated data are of concentration, mol/liter, and rate of inversion, polarimeter degrees/min. Find the constants of the rate equation... 

VI. Comparison of the Rates of Inversion and Oxygen and Cyanide Exchange... 

The proton transfer processes described above induce interesting effects on the geometry of these metal complexes upon protonation (see also Section II). If it is assumed that the equatorial cyano ligands form a reference plane and are stationary for any of these distorted octahedral cyano oxo complexes, the protonation/deprotonation process as illustrated in Scheme 3 is responsible for the oxygen exchange at the oxo sites. This process effectively induces a dynamic oscillation of the metal center along the O-M-O axis at a rate defined by kmv, illustrated in Fig. 15. This rate of inversion is determined by the rate at which the proton is transferred via the bulk water from the one... 

Hendrickson et al. 24 using the Westheimer-Allinger 19 method. Our calculated activation energy (6.0 kcal/mole) is less than those reported by Anet et al25) (10.3, 10.8 kcal/mole). Since, however, the barrier to inversion in per-fluorocyclohexane is 7.5 kcal/mole 26 and since the rates of inversion of cyclohexene and perfluorocyclohexane are very similar, the barrier reported for cyclohexane may be too large. 

The rate of inversion increased with increasing trans influence of X, and was more rapid than for the corresponding Pt complex.A preliminary account has appeared. 

Variable-temperature n.m.r. data on the chelates [PtX2(RSC2H4SR)] (X = Cl, Br, or I R = Me, Et, Pr, Pr , or Bu) have been interpreted in terms of inversion at S between the meso and ( + )-isomeric forms (59a M = Pt). The rate of inversion increased with increasing trans influence of X, and was slower than for the corresponding Pd complexes.A preliminary account has appeared. 

We expect racemization in this reaction, since if we start with the pure R isomer, at first each exchange will produce an S isomer, but with increasing concentration of S isomer, it will begin to compete for I with the R isomer, until at the end a racemic mixture is left. The point investigated was a comparison of the rate of inversion with the rate of uptake of radioactive I. It was found13 that the rates were identical within experimental error ... 

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