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SCH-Br Summary of spectra vs T, (slides: 3-7 (“hot”); 10-11(“cold”))

SCH-Br Summary of spectra vs T, (slides: 3-7 (“hot”); 10-11(“cold”)) calc. vs. exp. chemical shift differences for ax.-eq. (C2-C6, C3-C5, C4) (slides 11) DNMR-analysis for C3-C5 (slides: 12-14) PPT´s: https://notendur.hi.is/agust/rannsoknir/SCH/July12/SCH-Br-Sp.%20vs%20T-160712.ppt IGOR´s:

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SCH-Br Summary of spectra vs T, (slides: 3-7 (“hot”); 10-11(“cold”))

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  1. SCH-Br • Summary of spectra vs T, (slides: 3-7 (“hot”); 10-11(“cold”)) • calc. vs. exp. chemical shift differences for ax.-eq. (C2-C6, C3-C5, C4)(slides 11) • DNMR-analysis for C3-C5 (slides: 12-14) • PPT´s:https://notendur.hi.is/agust/rannsoknir/SCH/July12/SCH-Br-Sp.%20vs%20T-160712.ppt • IGOR´s: • https://notendur.hi.is/agust/rannsoknir/SCH/July12/SCH-Br-Sp.%20vs%20T-150712.pxp • XLS´s : https://notendur.hi.is/agust/rannsoknir/SCH/July12/SCH-X-Sp.%20vs%20T-150712.xlshttps://notendur.hi.is/agust/rannsoknir/SCH/July12/ibrcl-silacyclo-nmr.xlsx H Si Br Br Si H

  2. https://notendur.hi.is/agust/rannsoknir/SCH/July12/SCH-X-Sp.%20vs%20T-150712.xlshttps://notendur.hi.is/agust/rannsoknir/SCH/July12/SCH-X-Sp.%20vs%20T-150712.xls

  3. SCH-Br C3,C5 C4 C2,C6 ppm https://notendur.hi.is/agust/rannsoknir/SCH/July12/SCH-Br-Sp.%20vs%20T-150712.pxp

  4. SCH-Br C2,C6 ppm https://notendur.hi.is/agust/rannsoknir/SCH/July12/SCH-Br-Sp.%20vs%20T-150712.pxp

  5. SCH-Br X C3,C5 eq. ax. X ppm https://notendur.hi.is/agust/rannsoknir/SCH/July12/SCH-Br-Sp.%20vs%20T-150712.pxp

  6. SCH-Br C4 ppm https://notendur.hi.is/agust/rannsoknir/SCH/July12/SCH-Br-Sp.%20vs%20T-150712.pxp

  7. SCH-Br Calc, ax.-eq = +0.34 -3.83 -2.14 C3,C5 C4 C2,C6 ppm https://notendur.hi.is/agust/rannsoknir/SCH/July12/SCH-Br-Sp.%20vs%20T-150712.pxp https://notendur.hi.is/agust/rannsoknir/SCH/July12/ibrcl-silacyclo-nmr.xlsx

  8. Comments: • Chemical shift calculations seem to overestimate • abs(ax.-eq.) spacings for C2/C6 & C3/C5 • Not clear what is the case for C4 • Only possible to determne chemical shift for eq. For • C3,C5 • Further cooling needed to determine chemical shifts for eq. For C2,C6 and C4 New “colder” spectra added:

  9. SCH-Br C3,C5 C2,C6 C4 ppm https://notendur.hi.is/agust/rannsoknir/SCH/July12/SCH-Br-Sp.%20vs%20T-150712.pxp

  10. SCH-Br C3,C5 C2,C6 C4 eq eq ppm https://notendur.hi.is/agust/rannsoknir/SCH/July12/SCH-Br-Sp.%20vs%20T-150712.pxp , Layout:0, Gr:0

  11. SCH-Br C3,C5 C2,C6 C4 25.78859 ppm 22.89449 ppm ax.-eq = +0.34 -3.83 -2.14 -2.889 -1.284 Calc. Exp. eq eq ppm https://notendur.hi.is/agust/rannsoknir/SCH/July12/SCH-Br-Sp.%20vs%20T-150712.pxp https://notendur.hi.is/agust/rannsoknir/SCH/July12/ibrcl-silacyclo-nmr.xlsx

  12. DG# eq (eq->#; see below) G ax Si Br Si Br https://notendur.hi.is/agust/rannsoknir/SCH/July12/SCH-X-Sp.%20vs%20T-150712.xls

  13. C3,C5 analysis: https://notendur.hi.is/agust/rannsoknir/SCH/July12/SCH-X-Sp.%20vs%20T-150712.xls Coefficient values ± one standard deviation a =4.4628 ± 0.618 b =0.0074972 ± 0.00485 DG# (eq->#) Average: +/- DG# = DH# -TDS# => DH# = 4.46 kcal mol-1; DS# = +0.0075 kcal mol-1K-1 / +7.5 cal mol-1K-1 Tcorr https://notendur.hi.is/agust/rannsoknir/SCH/July12/SCH-Br-T-080812.pxp Lay:,0 Gr:0

  14. C3,C5 analysis: Or parabola fit: Coefficient values ± one standard deviation K0 =-9.9887 ± 4.34 K1 =0.23347 ± 0.0677 K2 =-0.00087287 ± 0.000261 DG# (eq->#) Average: +/- Tcorr https://notendur.hi.is/agust/rannsoknir/SCH/July12/SCH-Br-T-080812.pxp Lay:,0 Gr:0

  15. Simulation: Red: exp./black dots: calc. C3,C5 k(eq->ax): 44000 10000 800 520 260 170 ax eq 130 https://notendur.hi.is/agust/rannsoknir/SCH/July12/SCH-Br-T-080812.pxp Lay:,1 Gr:1

  16. Exp. Calc. T(K) keq,ax(s-1 ) 150 141 123 117 113 110 38000 10000 520 260 170 130

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