Thermal transformations of piperylene at various pressures

Shuikin, N. I.; Naryshkina, T. I.

doi:10.1007/bf01173787

Cited by 2 publications

(4 citation statements)

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“…The coefficients at f(e) and V M are positive, while that at E T is negative, which is consistent with the data of [2]. Shuikin and Naryshkina [1] reported the rate constants k 0 10 4 (l mol !1 h !1 ) for dimerization of cyclopentadiene at 20oC in its 1 : 1 mixtures with the following solvents: acetonitrile (5.9), diethyl ether (8.2), benzene (10.5), carbon tetrachloride (13.2), chlorobenzene (17.3), and dichloroethane (17.6). Dilution of cyclopentadiene with a solvent reduces the rate of its dimerization.…”

supporting

confidence: 86%

“…Spontaneous dimerization of cyclopentadiene slows down upon dilution with various solvents; the maximal deceleration (by a factor of 3.5) was observed in strongly polar acetonitrile [1]. However, C1 oster and Pfeil [2] studied the rate of cyclopentadiene dimerization in 16 solvents and found no clear relation betweem the secondorder rate constant k and such solvent parameters as dielectric constant e, dipole moment m, Hildebrand solubility parameter d, and Reichardt electrophilicity parameter E T [3].…”

mentioning

confidence: 97%

“…For example, Wong and Eckert [9] drew such a conclusion while considering the data on dimerization of cyclopentadiene and reaction of isoprene with maleic anhydridom; however, the log k3d 2 dependences given therein showed numerous deviations from linearity. Data on the solvent effect on the rate of dimerization of cyclopentadiene were also given in [1,9,11], but the low number of solvents (n = 6) makes it impossible to correlate them using a six-parameter equation. Only the data from reference book [11] may be generalized with some accuracy through a fourparameter equation having no basicity and cohesion energy density terms.…”

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confidence: 99%

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Solvent Effect on the Rate of Dimerization of Cyclopentadiene

Karpyak¹,

Makitra

Marshalok³

et al. 2005

Russ J Gen Chem

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The rate of dimerization of cyclopentadiene and some other cycloaddition reactions is determined by electrophilic solvation of the substrate with some contribution of other solvation factors, primarily nonspecific solvation. The corresponding dependence is described by multiparameter equations.Spontaneous dimerization of cyclopentadiene slows down upon dilution with various solvents; the maximal deceleration (by a factor of 3.5) was observed in strongly polar acetonitrile [1]. However, C1 oster and Pfeil [2] studied the rate of cyclopentadiene dimerization in 16 solvents and found no clear relation betweem the secondorder rate constant k and such solvent parameters as dielectric constant e, dipole moment m, Hildebrand solubility parameter d, and Reichardt electrophilicity parameter E T [3]. A certain relation (with a number of exceptions) was revealed between log k values and enthalpies of vaporization of the solvents: reduction of the latter parameter by a factor of 2 in going from 1-butanol to diethyl ether leads to decrease in k to a comparable extent. The authors concluded that, in the general case, solvent effect on a dissolved substance cannot be described using a single parameter owing to specific interactions.On the other hand, it is known that interactions of a solute with the solvent can be generalized on the basis of the linear Gibbs energy relationship principle by summation of effects produced by various solvation processes via multiparameter equations [4]. Among the latter, one of the most effective is the extended Koppel'3Pal'm equation which takes into account not only specific and nonspecific solvation but also structural features of the medium [5]. In the present work we made an attempt to generalize the data given in [2] on the rate constants for dimerization of cyclopentadiene at 40oC in 0.6 M solutions using Eq. (1): log k = a 0 + a 1 777 + a 2 777 n 2 3 1 n 2 + 2 e 3 1 2e + 1 + a 3 B + a 4 E T + a 5 d 2 + a 6 V M .(1)Here, n and e are, respectively, the refractive index and dielectric constant which determine solvent polarizability and polarity (i.e., factors responsible for nonspecific solvation); B is the basicity according to Pal'm [4], and E T is the Reichardt electrophilicity parameter [3] (these quantities characterize solvent ability for acid3base interactions, i.e., specific solvation); d is the Hildebrand solubility parameter (its squared value is proportional to the cohesion energy density); and V M is the molar volume which takes into account possible effect of structural factors. The solvent parameters were taken from [4] and reviews [6,7], and the calculation procedure conformed to the IUPAC recommendations concerning the application of correlation analysis in chemistry [8]. The corresponding data are collected in Table 1.However, processing of the data for 17 solvents according to Eq. (1) resulted in a too low [8] multiple correlation coefficient (R = 0.925). However, to reach an acceptable correlation quality, it was sufficient to exclude the most deviating data for only one s...

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confidence: 86%

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confidence: 97%

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confidence: 99%

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Solvent Effect on the Rate of Dimerization of Cyclopentadiene

Karpyak¹,

Makitra

Marshalok³

et al. 2005

Russ J Gen Chem

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“…The data are shown in Table II, and the comparison with the regular solution method is presented in Figure 2. The dimerization in the pure liquid has been done by several authors (Harkness et al, 1937;Schmid et al, 1948;Shuikin and Naryshkina, 1957;Wassermann, 1952). The deviations among the various authors and consequently the disagreement with the predictions of the regular solution theory are within the experimental error estimated by Wassermann (1952).…”

Section: Transition State Theorymentioning

confidence: 85%

Solvent Design for Chemical Reactions

Wong¹,

Eckert²

1969

Ind. Eng. Chem. Proc. Des. Dev.

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Thermal transformations of piperylene at various pressures

Cited by 2 publications

References 5 publications

Solvent Effect on the Rate of Dimerization of Cyclopentadiene

Solvent Effect on the Rate of Dimerization of Cyclopentadiene

Solvent Design for Chemical Reactions

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