Dichlorobenzene, calculated benzene

This relationship proves that the influence of solvents (decane, benzene, acetic acid, p-dichlorobenzene) on the rate constant is due to the nonspecific solvation of the reactants and the transition state. The values of the dipole moments of the TS calculated from experimenntal data within the scope of Equation (18.2) have the following values [87] ... 

For a hypothetical sorbent with properties listed in Table II, we assume that experiments have shown that sorption of dichlorobenzene (log Kqw = 3.3) is 95% complete within one day. R equals 1000 on the basis of the correlation of Karickhoff et al. (15). If we estimate Rp for other solutes from the same correlation and assume negligible mineral sorption, we may estimate the time required to reach 95% of equilibrium for other compounds. These calculations imply that approximately 0.1 days will be required to reach 95% equilibrium for benzene (log KQw = 2.1), approximately 10 days for 1,2,4,5-tetrachlorobenzene (log Kow = 4.7) and approximately 100 days will be required for hexachlorobenzene (log KQW - 5.5). 

The rate constant for OH radical addition cannot be calculated because the effect of the -OP(=S)(OCH2CH3)2 substituent is not known. However, because the rate constant for OH radical addition to pyridine is -3.7 x 10-13 cm3 molecule-1 s-1 (Atkinson, 1989) and the three Cl atom sustituents will markedly deactivate the ring (Brown and Okamoto, 1958) [as observed, for example, for the OH radical reactions with chlorobenzene, 1,2-, 1,3- and 1,4-dichlorobenzene, and for 1,2,4-trichlorobenzene relative to that for benzene (Atkinson, 1989)], OH radical addition to the pyridine ring is expected to be minor, and its neglect will lead to an estimated lower limit to the total reaction rate constant. 

In all cases, both permeability and diffusivity of methyl-substituted benzenes vary in an inverse manner with their molecular volumes (as calculated by dividing the molecular weight by density and Avogadro number to yield the volume per molecule). For other penetrants, namely, anisole, nitrobenzene, chlorobenzene, -dichlorobenzene and bromobenzene, the volume per molecule varies in the range 17-19. However, their diffusion trends are quite different. For instance, though nitrobenzene and chlorobenzene... 

The pivalate derivative Mo2(02CC(CH3)3)4 was prepared most conveniently by reaction of Mo(CO)g with the calculated amount of pivalic acid in refluxing o-dichlorobenzene. The compound crystallized as slender yellow needles when the reaction mixture was cooled to room temperature it was filtered, washed with benzene and cyclohexane, and dried in vacuo. IR data for Moo(02CC(CH3)3)4 are included in Table I. The following lines were observed in the X-ray powder pattern 11.49 w, 10.46 s, 9.16 s, 6.36 s, 5.69 m, 5.51 m, 5.01 s, 4.59 s, 4.26 w, and 4.13 m. 

The frequency of rotation of the difluorobenzene ring was determined to be 1.8 x 10 Hz. We also obtained a similar plot for the rotational dihedral angle of the dichlorobenzene ring versus time. The results are found in Figure 8. For the dichlorobenzene ring, the frequency of rotation is estimated to be 3.6 X 10" Hz. The difference in the calculated frequencies between the two dihalo-substituted benzene rings demonstrates that different frequencies of electromagnetic radiation are required to stimulate rotation for each. 

Properties Golden yellow leaflets or crystals. Mp 193°C (sublimes >32°C) bp 275°C at 2 mmHg log 4.19 (calculated) log 5.62 (calculated) S moderately soluble in acetone, acetic acid, benzene, o-dichlorobenzene ( 4 wt %), TVyA-dimethylformamide, 1,4-dioxane, ethanol, ethylbenzene, ethyl ether, ethyl acetate, toluene, xylene ( 4 wt %) and many other organic solvents S 1.0 mg/L at 25" C. 

In collaboration with experimental groups, we have recently studied some chlorinated-benzene crystals, 1,2,4,5-tetrachlorobenzene (TCB) [59] and 1,4-dichlorobenzene (DCB) [60], as well as solid tetracyanoethene (TCNE) [58]. In these studies we have used empirical atom-atom potentials, of exp-6 type [see Eq. (6)], which we have supplemented with the Coulomb interactions between fractional atomic charges. Lattice dynamics calculations have been performed by the harmonic method, with inclusion of intramolecular vibrations [70], see Eqs. (17) to (24). The normal modes of the free molecules have been calculated from empirical Valence Force Fields, using the standard CF-matrix method [101, 102]. The results of these calculations are used here to illustrate some phenomena occurring in more complex molecular crystals. These phenomena are well known the numerical results show their quantitative importance, in some specific systems. 

Benzene, chlorobenzene, dichlorobenzene and trichlorobenzene are four major products formed in the pyrolysis of vinylidene chloride/vinyl chloride copolymer. To make the composition calculation, the first assumption is that all trimer peak intensities generated from the Py-GC after correction for pyrolysis efficiency and detection efficiency accurately represent the triad distribution of the vinylidene chloride/vinyl chloride copolymer. If a close relationship exists between the triad distribution in the polymer chain and the production of trimers in pyrolysis, the composition and number average sequence length can be calculated on the basis of the trimer production in the pyrolysis. Results were in good agreement with those obtained by H-NMR (Table 4.11). Copolymers containing 11 wt% and 5 wt% vinyl chloride and 5% and 89% vinylidene chloride were successfully analysed. 

The crosslink densities were calculated from swelling measurements in benzene and o-dichlorobenzene through the use of the Flory-Rehner equation [14,15]. For the natural rubber-benzene system, a value of X = 0.44 was used, and for NR-o-dichlorobenzene, x = 0.32. Consistent crosslink densities were obtained from both solvents. 

The temperature behavior of the relaxation times of in benzene-dg, chloroben-zene-d, o-dichlorobenzene-d and in the solid-state are illustrated in Figures 2, 3 4, and 5 respectively. Tables 6, 7, 8, and 9 contain the reorientational correlation times of the various carbons, as well as the calculated diffusion coefficients, of C. 

Vacuum calculations of a xylene molecule or a pair of xylenes are performed in a large box of 20 x 20 x 20 and are labeled with vac . The investigated molecules are para-xylene (pX), ortho-xylene (oX), and meta-xylene (mX). In addition, benzene (Bz) and dichlorobenzenes in para-, ortho-, and meta-configuration (pCl, oCl, mCl) are simulated in vacuum for comparison. 

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