Thakur Rajendra Singh, Kurur Narayanan D, Madhu P K
Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005, India.
J Magn Reson. 2008 Jul;193(1):77-88. doi: 10.1016/j.jmr.2008.04.024. Epub 2008 Apr 23.
The design of variants of the swept-frequency two-pulse phase modulation sequence for heteronuclear dipolar decoupling in solid-state NMR is reported, their performance evaluated, and compared with other established sequences like TPPM and SPINAL. Simulations performed to probe the role of the homonuclear (1)H-(1)H bath show that the robustness of the decoupling schemes improves with the size of the bath. In addition, these simulations reveal that the homonuclear (1)H-(1)H bath also leads to broad baselines at high MAS rates. Results from a study of the SPINAL decoupling scheme indicate that optimisation of the starting phase and phase increment improves its performance and efficiency at high MAS rates. Additionally, experiments performed on a liquid crystal display the role of the initial phase in SPINAL-64 and sequences in the SW(f)-TPPM family.
本文报道了用于固态核磁共振异核偶极去耦的扫频双脉冲相位调制序列变体的设计，评估了它们的性能，并与其他成熟序列（如TPPM和SPINAL）进行了比较。为探究同核(1)H-(1)H浴的作用而进行的模拟表明，去耦方案的稳健性随着浴的大小而提高。此外，这些模拟还表明，同核(1)H-(1)H浴在高MAS速率下也会导致宽基线。对SPINAL去耦方案的研究结果表明，起始相位和相位增量的优化提高了其在高MAS速率下的性能和效率。此外，在液晶上进行的实验展示了SPINAL-64和SW(f)-TPPM系列序列中初始相位的作用。
