NMR spectroscopy

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Presentation transcript:

NMR spectroscopy

Calculation of NMR spectra 1. (Optimize) the geometry of your molecule (complex) 2. Calculate the NMR spectrum of the molecule #P NMR(Giao) Iop33(10=1) B3LYP/6-31G(d) 3. Extract the isotropic part of the magnetic shielding tensors found under the heading: SCF GIAO Magnetic shielding tensor (ppm): in the output file 4. Calculate the NMR spectrum of the reference (TMS) using the same method and basis set as for the molecule of interest 5. Extract the isotropic part of the magnetic shielding tensors of the reference molecule TMS, B3LYP/6-31G(d)

6. Obtain the chemical sifts of your nuclei by subtracting their isotropic part of the magnetic shielding tensors from the calculated value for the corresponding nucleus in the reference molecule δ(C1)= =144.4 ppm δ(C1)= =8.72 ppm 7. If you want the spin-spin splittings, use the following keyword: NMR(spinspin) and find the spin-spin splittings in the output file under the heading: J 24 =J 42 =12.14Hz 8. If you want to model solvent effects by using discrete models, construct the molecular complex by adding solvent molecule(s) in the vicinity of your molecule of interest. Repeat steps 1-6. Calculate the NMR spectrum for different tautomers of uracil. Simulate the solvent effects on chemical shifts by using a discrete model.

ESR spectroscopy

Calculation of ESR spectra 1. (Optimize) the geometry of your molecule (complex) 2. Calculate the ESR spectrum of the molecule #P B3LYP/6-31G(d) Prop=EPR by default, for open-shell systems, isotropic hyperfine coupling constants (hfcc’s of the non-zero spin nuclei (isotopes) will be calculated If you need the hyperfine coupling tensors, you must add in the route section Prop=EPR 3. Find the isotropic coupling constants in the output file under the heading:

3. Find the dipolar part of the hyperfine coupling tensors (principal values) in the output file under the heading: 4. Simulate the solvent effects by using discrete or continuum solvation models Calculate the ESR spectrum for the glycine · CH2COO - free radical