How come there is a drop-down menu that allows me to specify a particular solvent for calculations in ACD/CNMR but not in ACD/HNMR?
As solvents used in C13 experiments contain carbons they always add lines to the spectrum and always at the same positions. It is therefore easy to provide the exact lines for these solvents in our predicted spectrum. It should be noted that even though we provide these typical solvent lines ACD/CNMR is not calculating the actual solvent effect on the solute. In H1 experiments solvents are deuterated and as they should not contain protons, theoretically, should not add lines to the spectrum which is why we do not provide these in a drop-down menu (in practice residual proton resonances are observed due to small impurities in the solvent; ACD/HNMR does not provide these lines). Solvents do however affect the positions of the shifts for the actual solute. These solvent effects are very difficult to predict in the absence of large amounts of published data that we normally require for writing algorithms. Therefore ACD/HNMR always assumes an aprotic/non-polar, non-aromatic solvent (e.g. CC
Related Questions
- In the Table of Chemical Shifts in both the ACD/HNMR and ACD/CNMR there is a column on the far right that is labelled Confidence Limits. How do the programs generate these error margins?
- How come there is a drop-down menu that allows me to specify a particular solvent for calculations in ACD/CNMR but not in ACD/HNMR?
- Does ACD/HNMR take solvent effects into account when generating predicted spectra?
