DIRECT MEASUREMENT OF THE INVERSE SECONDARY ISOTOPE EFFECTS OF RH(I)-C2H4 AND RH(I)-C2H3D UTILIZING GAS-CHROMATOGRAPHY
Youn, DY; Hong, KB; Jung, KH; Kim, D; Kim, KR
| HERO ID | 4972367 |
|---|---|
| In Press | No |
| Year | 1992 |
| Title | DIRECT MEASUREMENT OF THE INVERSE SECONDARY ISOTOPE EFFECTS OF RH(I)-C2H4 AND RH(I)-C2H3D UTILIZING GAS-CHROMATOGRAPHY |
| Authors | Youn, DY; Hong, KB; Jung, KH; Kim, D; Kim, KR |
| Journal | Journal of Chromatography A |
| Volume | 607 |
| Issue | 1 |
| Page Numbers | 69-77 |
| Abstract | The inverse secondary equilibrium isotope effects of Rh(I)-C2H4 and Rh(I)-C2H3D were directly measured using a gas chromatographic column of dicarbonyl-rhodium(I)-3-trifluoroacetyl-1R-camphorate in squalane solution at 283-333 K. Statistical isotope effects were also obtained from a reduced partition function using harmonic vibrational frequencies of RHC-C2H, complexes and normal-mode analysis. The observed isotope effects were in good agreement with those deduced from the reduced partition function. Thermodynamic data of the inverse isotope effect were DELTA(D.H)-DELTA-H = - 469 +/- 12 J mol -1 and DELTA(D.H)DELTA-S = - 0.975 +/- 0.017 J mol -1 K -1, where DELTA(D,H)-DELTA-H = DELTA-H(D) - DELTA-H(H) = the difference of the enthalpy changes of the deuterated and non-deuterated compounds (see refs. 1 and 22) and DELTA(D.H)-DELTA-S = DELTA-S(D) - DELTA-S(H) = the difference of the entropy changes of the deuterated and non-deuterated compounds. The detailed analysis of the force constant most affected, F(C-C) = 8.39 mdyn/angstrom, by metal complexation was closer to that of the carbon-carbon double bond (9.1 mdyn/angstrom) than to that of the carbon-carbon single bond (4.3 mdyn/angstrom). |
| Doi | 10.1016/0021-9673(92)87055-D |
| Wosid | WOS:A1992JL06600009 |
| Is Certified Translation | No |
| Dupe Override | No |
| Is Public | Yes |