Solvent Suppression in Intermolecular Multiple-Quantum Coherence Nuclear Magnetic Resonance Spectra with Only z-axis Gradients

The solvent peak in the intermolecular multiple-quantum coherence spectra can be suppressed by either applying pulse field gradients or spinning sample along the magic angle direction (ψ=54.7). However, these two methods also suppress the signals of the solute. We design　two pulse sequences with only z-axis gradients to suppress the　solvent peak without reducing the intensity of solute signals. Compared　to the former pulse sequence, the latter pulse sequence is insensitive　to the imperfection of pulse flip angles. When the flip angles of the　second pulse sequence are purposely deviated 1/10 from the optimal　values, the solvent peak is still weak. Theoretical expressions,　experimental observations and computer simulations demonstrate that the　two methods can be used to effectively suppress solvent peak in　intermolecular multiple-quantum coherence spectra.