Dipole moment of ethylene

Use Learning By Modeling to compare the calculated dipole moments of ethylene propene vinyl chloride and trans 1 chloropropene Unlike measured dipole moments the calculated ones do show the direction of the dipole moment How do the directions of the calculated dipole moments compare with those deduced by experimenf ... 

Table S. Boiling Points and Dipole Moments of Ethylenes [17,18]...

Compare the dipole moment of ethylene and formaldehyde. Then compare the HOMO and LUMO in both molecules. Use the data from the formaldehyde example earlier in this chapter. 

The dipole moment of ethylene oxide is the result of non-uniform electron distribution in o-bonds, and is caused by the presence of an... 

The dipole moment of ethylene glycol is zero because the bond polarities of the two carbon-oxygen bonds cancel. 

The dipole moments of ethylene sulfite (1) ()u. = 3.74 D in benzene), ethylene sulfate (2) (ix = 5.64 D in dioxane), and tetramethyl cyclic sulfate (ij. = 6.05 D in dioxane) have been measured. These measurements support the nonplanar ring structure of this class of compounds. 

Gillies, J.Z., Gillies, C.W., Suenram, R.D., Lovas, F.J. The ozonolysis of ethyltme. Microwave spectrum, molecular structure, and dipole moment of ethylene primary ozonide (1,2,3-trioxolane). J. Am. Chem. Soc. 110, 7991-7999 (1988)... 

Ethers like water and alcohols are polar molecules Diethyl ether for example has a dipole moment of 1 2 D Cyclic ethers have larger dipole moments ethylene oxide and tetrahydrofuran have dipole moments m the 1 7 to 1 8 D range—about the same as that of water (1 8D)... 

The chemistry of propylene is characterized both by the double bond and by the aHyUc hydrogen atoms. Propylene is the smallest stable unsaturated hydrocarbon molecule that exhibits low order symmetry, ie, only reflection along the main plane. This loss of symmetry, which implies the possibiUty of different types of chemical reactions, is also responsible for the existence of the propylene dipole moment of 0.35 D. Carbon atoms 1 and 2 have trigonal planar geometry identical to that of ethylene. Generally, these carbons are not free to rotate, because of the double bond. Carbon atom 3 is tetrahedral, like methane, and is free to rotate. The hydrogen atoms attached to this carbon are aUyflc. 

Dipole moments of substituted nitriles were correlated with the a constants by Taft and with the Op constants by Charton (18). In addition to dipole moment data, some information is available on the C=N stretching frequencies of substituted nitriles. The sets studied are reported in Table XXXVI. Results of the correlations with eq. (2) are given in Table XXXVII, and values of Pr are set forth in Table XXXVIII. The correlation of the dipole moments of substituted nitriles with eq. (2) gave significant results, which were very much improved by the exclusion of the value for X=I (set 36-1-2). In contrast to the results obtained for substituted ethylenes, acetylenes, and benzenes, the value of /3 obtained for dipole moments of substituted nitriles is not significant. The value of a obtained for the substituted nitriles is comparable to the value of a observed for the substituted acetylenes. 

The separation of formal charges in a polar limiting structure like 2b creates a dipole moment of ca. 20 D. Therefore, if such structures were of great importance, quite high dipole moments should be expected for push-pull ethylenes. Data for a reasonable number of mostly symmetrical and rather rigid compounds are known (Table 20). Several high dipole moments are observed, though not in the vicinity of those required for a complete transfer of the double-bond it... 

Mean-square dipole moments of polylthiodiethylene gycol), an alternating copolymer of ethylene oxide and ethylene sulfide, are determined from dielectric constant measurements on dilute solutions of the polymer in benzene. Since the configuration-dependent properties of one of the parent homopolymers, PES, are unknown, because of its insolubility in ordinary solvents, the results are preferably compared with those of POE chains. It is found that the dipole moments of polylthiodiethylene glycol) are somewhat larger than those of POE. 

For less polar compounds, the solvent effect is weak. However, if the dipole moment of the chromophore increases during the transition, the final state will be more solvated. This is the case for n — n transitions in ethylenic hydrocarbons with a slightly polar double bond. A polar solvent has the effect of stabilising the excited state, which favours the transition. A shift towards greater wavelengths is observed unlike the spectrum obtained in a nonpolar solvent. This is the bathochromic effect. 

Values of the dipole moments of sulfones, including ethylene episulfone, were computed by Rozas at different computational levels (HF 6-31G and MP2 6-31G HF-6 31G ) and different methods of charge estimation <1997IJQ477>. Numbers ranged from 5.946 to 3.901 D. The experimental value of the dipole moment is 4.41 D. 

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