Doan Peter E, Lees Nicholas S, Shanmugam Muralidharan, Hoffman Brian M
Department of Chemistry, Northwestern University, Evanston, IL, 60208-3113.
Appl Magn Reson. 2010 Jan 1;37(1-4):763-779. doi: 10.1007/s00723-009-0083-6.
All pulsed ENDOR techniques, and in particular the Mims and Davies sequences, suffer from detectability biases ('blindspots') that are directly correlated to the size of the hyperfine interactions of coupled nuclei. Our efforts at ENDOR 'crystallography' and 'mechanism determination' with these techniques has led our group to refine our simulations of pulsed ENDOR spectra to take into account these biases, and we here describe the process and illustrate it with several examples. We first focus on an issue whose major significance is not widely appreciated, the 'hole in the middle' of pulsed ENDOR spectra caused by the n = 0 suppression hole in Mims ENDOR and by the analogous A→0 suppression in Davies ENDOR (Section I). This section discusses the issue for nuclei with I = ½ and also for (2)H (I = 1), using the treatment of Section II. In Section II we discuss the general treatment of suppression effects for I = 1, illustrating it with a treatment of Mims suppression for (14)N (I = 1) (Section II).
所有脉冲电子核双共振（ENDOR）技术，尤其是米姆斯（Mims）序列和戴维斯（Davies）序列，都存在可检测性偏差（“盲区”），这些偏差与耦合核的超精细相互作用大小直接相关。我们利用这些技术在ENDOR“晶体学”和“机理确定”方面所做的努力，促使我们的团队改进了对脉冲ENDOR谱的模拟，以考虑这些偏差。我们在此描述该过程，并通过几个例子进行说明。我们首先关注一个其重要性尚未得到广泛认识的问题，即米姆斯ENDOR中由n = 0抑制空洞以及戴维斯ENDOR中类似的A→0抑制所导致的脉冲ENDOR谱的“中间空洞”（第一节）。本节使用第二节的处理方法，讨论了I = ½的核以及（2）H（I = 1）的该问题。在第二节中，我们讨论了I = 1时抑制效应的一般处理方法，并通过对（14）N（I = 1）的米姆斯抑制处理进行说明（第二节）。
