Propylene carbonate equation

Figure 8. Comparison of observed and calculated values for AGt° (molar standard state) for the transfer of salts from water to propylene carbonate. The electrostatic contribution was estimated from Equation 69 with n = 4 (Li+, Na+, K + ), n = 8 (Cl, 04B ), and the following solvated radii in A 3.6 (Li +), 3.9 (Na +), 4.2 (K +), 4.3 (Cl and 6.9 (AB )...

The effect of solvent on the total free energy of a BA/solvent system is represented in Figure 22 for a polar solvent such as propylene carbonate. A corresponding plot for BA in a nonpolar solvent is given in Figure 23. These zero order (uncoupled) curves for the various configurations correspond to the following equations. 

When Desilvestro and Pons used in situ IR reflection spectroelectrochemistry to observe the reduction of C02 to oxalate at Pt electrodes in acetonitrile [83], two different forms of oxalate were observed. Similarly, Aylmer-Kelly et al. studied C02 reduction in acetonitrile and propylene carbonate at Pb electrodes [84], by using modulated specular electroreflectance spectroscopy. Subsequently, two radical intermediates were observed which they determined to be the C02 radical anion, C02, and the product of the radical anion and C02, the (C02)2 adduct (see Equations 11.9 and 11.10). Vassiliev et al. also studied the reduction of C02 in... 

DBU DMC DMF EC EO EOS GSS ILs MBMTBP MEA MW PC PDMS PEG PEGda PEO PMPS PO PPG PPGda PTC PTHF PTMO PVP Diazabicyclo[5.4.0] -undec-7-ene Dimethylcarbonate Dimethylform amide Ethylene carbonate Ethylene oxide, oxyethylene Equation of state Gas-saturated solution Ionic liquids 2,2,-methylene-bis(4-methyl-6-tert-butylphenol) Monoethanolamine Molecular weight Propylene carbonate Polydimethylsiloxane Polyethylene glycol Poly(ethylene glycol) diacrylate Polyethylene oxide Poly(methylphenylsiloxane) Propylene oxide Poly(propylene glycol) Poly(propylene glycol) diacrylate Phase-transfer catalyst Poly(tetrahydrofuran) Polytetramethylene oxide Polyvinyl pyrrolidone... 

Equation (4-5) typically applies up to temperatures of Tg + 50 C or so. For higher temperatures, an Arrhenius temperature-dependence often applies for small-molecule liquids, even if they are fragile glass formers. For example. Fig. 4-6 shows a plot of 1/ logio(/oo/fp) versus temperature for propylene carbonate, where fp = Incop is the peak frequency (in... 

Oxidation of trisubstituted N, N, IV -1 r i p h on y I -1,3,5 - tr i am i n o ben zcn cs (2a-2e) showed one to three irreversible cyclic voltammetric peaks. Potentials of the first peak fulfill the Hammett equation (against the 3 cr+ values, according to the additivity rule for three para-substituents) giving the slopes, i.e. the reaction constants p+, equal to —1.53, —1.45 and — 1.43 V/(3a+ unit) in solutions of methylene chloride, ACN and propylene carbonate, respectively (solutions contained 0.1 M tetrabutylammonium perchlorate)15. An interpretation of the above reaction constants is rather difficult because of the irreversibility (radical cations formed by the first electron transfer evidently disappear in fast chemical steps). However, relatively small values of p+ may be related15 to a charge delocalization onto the outer aromatic ring of the radical cation. 

By the dipole moment criterion, the cyclic compounds would be expected to show appreciably greater polarities. They do not. For example, the ir values (Table 17) are essentially the same for the open-chain and cyclic compounds. These results are in accord with the 0(fB) function, which has nearly the same values for the corresponding open-chain and cyclic compounds. Propylene carbonate (PC) provides a further case of interest. This solvent has a dipole moment and a dielectric constant (4.9 D and 65.1, respectively (70)) which are both substantially larger than those of DMSO (3.9 D and 48.9, respectively). According to the TT-/X correlation (Equation 38) their tt values would be MoAfso = 0.93 and (7t)pc = T16, that is, PC would be 25% more polar than DMSO. The TT — 0(tg) correlation, on the other hand, predicts (7r)o /so = 0.947 and (ir) c = 1 000, that is, the latter would be some 5% more polar than DMSO. Experimentally, DMSO and PC are extremely close, as shown in Table 19. These results seem indeed to favor the correlation with 0( b). 

The InKa - 1/e dependence for universal media is linear in full range of permittivity. Validity of the following equation was evaluated for the mixed solvent propylene carbonate - 1,4-dioxane in the range of permittivity e=65 3 for the solutions Et4NBr... 

Drago developed a universal polarity scale (the S scale) from more than three hundred spectral data (electronic transitions, F and N chemical shifts and RSE coupling constants) for 30 solutes in 31 non-protic solvents from cyclohexane to propylene carbonate. He used the equation... 

FIGURE 9 Specific conductivity k versus molarity m at 25°C for BU4NCIO4 in mixed solvents propylene carbonate-acetonitrile (mole fraction of acetonitrile is indicated on the right side of each curve). Points measured data full lines Eq (79) dashed lines MSA equation. 

The data analysis with the help of Eqs. (83), (84), (87), and (88) where association constants are used with MSA activity coefficients [Eqs. (90), (91), (92)] yields a good reproduction of experimental data up to molar concentrations. As an example. Fig. 9 shows the conductivity of BU4NCIO4 in the mixed solvent system acetonitrile-propylene carbonate. Comparison is made of measured data with MSA and the Amis-Casteel equation, which both exactly reproduce the conductivity maximum at every solvent composition. 

In general, polar solvents speed up the quaternization reaction322-4 . To some extent the effect of solvents follows their dipole moments322 but the connection is not general, and with solvents of high polarity (tetramethylene sulphone, D = 42 propylene carbonate, D = 65 1) examples are known of quaternizations which are faster in the less polar medium3246. The reaction of pyridine with alkyl halides has been used to elucidate the ways in which the parameters of the Arrhenius equation vary with changes in solvent 323, 324, 325 YoT preparative purposes alcohol is often used as the solvent, but for slow reactions nitrobenzene is useful. 

A cell was constructed by employing cis-FA film as cathode and lithium metal as anode and immersing them in an electrolyte of 1 m LiC104 in propylene carbonate. The overall charging process involves oxidation or p-doping of PA with perchlorate ions and reduction of lithium ions to metals, as shown by the equation... 

Using the Hansen equation for the surface tension (Equation 3.14), estimate the dispersion, the polar and the hydrogen bonding contributions of the surface tension of propylene carbonate (y, y, y ). 

The (total) smface tension of propylene carbonate is (see table in the problem) 40.7 mN m According to the Hansen equation for the surface tension, we have ... 

From the above equation, we calculate the /-value, which best fits the data. This is / = 0.504. Using this value and Equation 6.2.1, we can estimate the three surface tension contributions of propylene carbonate ... 

The surface tension contributions of Teflon will be estimated based on Equation 6.2.2, applied twice, for the octane/Teflon and propylene carbonate/Teflon systems. From the octane/Teflon system, we can estimate the dispersion surface tension contribution of Teflon, since the other two terms apparently vanish (no polar and hydrogen bonding contributions of octane). Thus, for octane/Teflon we have ... 

Using this value and again Equation 6.2.2, this time for propylene carbonate/Teflon, we can estimate the polar and hydrogen bonding surface tension contributions of Teflon, assuming that they are equal to each other ... 

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