Solid-state NMR spectroscopy has played a significant role in elucidating the structure and dynamics of materials and biological solids at a molecular level for decades. In particular, the ¹H double-quantum/single-quantum (DQ/SQ) chemical shift correlation experiment is widely used for probing the proximity of protons, rendering it a powerful tool for elucidating the hydrogen-bonding interactions and molecular packing of various complex molecular systems. Two factors, namely, the DQ filtering efficiency and t₁-noise, dictate the quality of the 2D ¹H DQ/SQ spectra. Experimentally different recoupling sequences show varied DQ filtering efficiencies and t₁-noise. Herein, after a systematic search of symmetry-based DQ recoupling sequences, we report that the symmetry-based γ-encoded $R{N}_n^{\nu }$ sequences show superior performance to other DQ recoupling sequences, which not only have a higher DQ recoupling efficiency but can also significantly reduce t₁-noise. The origin of t₁-noise is further discussed in detail via extensive numerical simulations. We envisage that such γ-encoded $R{N}_n^{\nu }$ sequences are superior candidates for DQ recoupling in proton-based solid-state NMR spectroscopy due to its capability of efficiently exciting DQ coherences and suppressing t₁-noise.

几十年来，固态核磁共振光谱在阐明分子水平的材料和生物固体的结构和动力学方面发挥了重要作用。特别是¹ H 双量子/单量子 (DQ/SQ) 化学位移相关实验被广泛用于探测质子的接近性，使其成为阐明各种复杂的氢键相互作用和分子堆积的有力工具分子系统。两个因素，即 DQ 滤波效率和t ₁噪声，决定了 2D ¹ H DQ/SQ 光谱的质量。实验上不同的重新耦合序列显示出不同的 DQ 滤波效率和t ₁-噪音。在此，在对基于对称的 DQ 重新耦合序列进行系统搜索后，我们报告了基于对称的 γ 编码$R{ñ}_n^{\nu }$序列表现出优于其他 DQ 再耦合序列的性能，不仅具有更高的 DQ 再耦合效率，而且还可以显着降低t ₁噪声。通过广泛的数值模拟进一步详细讨论了t ₁噪声的起源。我们设想这种 γ 编码$R{ñ}_n^{\nu }$序列是基于质子的固态 NMR 光谱中 DQ 再耦合的优秀候选者，因为它能够有效地激发 DQ 相干性和抑制t ₁ -噪声。