Unlike 1D NMR, which provides information on individual nuclei, 2D NMR experiments correlate the interactions between two different nuclei or between the same nucleus at two different times. This is achieved through a series of radiofrequency pulses and delays, resulting in a 2D spectrum that displays the correlations. Common types of 2D NMR include COSY (Correlation Spectroscopy), HSQC (Heteronuclear Single Quantum Coherence), and NOESY (Nuclear Overhauser Effect Spectroscopy).
