The Synergy between Nuclear Magnetic Resonance and Density Functional Theory Calculations

Area of Science:

• Computational Chemistry
• Spectroscopy
• Structural Chemistry

Background:

• Nuclear Magnetic Resonance (NMR) spectroscopy is a powerful tool for molecular structure determination.
• Density Functional Theory (DFT) calculations offer theoretical insights into molecular properties.
• Synergistic application of experimental NMR and theoretical DFT is often required for complex chemical systems.

Purpose of the Study:

• To demonstrate the indispensable synergy between NMR spectroscopy and DFT calculations.
• To highlight applications where combining these methods yields crucial results unobtainable by either alone.
• To present both published findings and novel results in this integrated approach.

Main Methods:

• Experimental Nuclear Magnetic Resonance (NMR) spectroscopic investigations.
• Theoretical Density Functional Theory (DFT) calculations of NMR parameters.
• Comparative analysis of experimental and calculated NMR data for various molecular systems.

Main Results:

• Successful analysis of tautomeric systems by calculating NMR data for different tautomers.
• Improved determination of XH bond lengths in hydrogen-bonded systems through combined methods.
• Accurate assignment of NMR spectra for cage compounds, ionic compounds, and solid-state structures, including crystal forms.

Conclusions:

• The integration of NMR spectroscopy and DFT calculations is essential for resolving complex structural challenges.
• This combined approach enables the revision of existing structural assignments and the creation of valuable data libraries for biological molecules.
• Novel insights were gained into substituent effects on pyrroles and the revision of a cage structure.