مقایسهٔ روش‌ها

	NMR Spin-Echo	کوسی (COSY)	همبستگی کوانتومی منفرد ناهمگن (HSQC)
حوزه	طیف‌سنجی	طیف‌سنجی	طیف‌سنجی
خانواده	Process / pipeline	Process / pipeline	Process / pipeline
سال پیدایش	1950	1976	1980
پدیدآور	Erwin Hahn	Wüthrich Kurt	Anil Kumar
نوع	Spectroscopic pulse sequence	Two-dimensional pulse sequence	Heteronuclear correlation sequence
منبع بنیادین	Hahn, E. L. (1950). Spin echoes. Physical Review, 80(4), 580-594.	Aue, W. P., Bartholdi, E., & Ernst, R. R. (1976). Two-dimensional spectroscopy. Application to nuclear magnetic resonance. The Journal of Chemical Physics, 64(5), 2229-2246.	Bodenhausen, G., & Ruben, D. J. (1981). Natural abundance nitrogen-15 NMR by enhanced heteronuclear spectroscopy. Chemical Physics Letters, 69(2), 185-189.
نام‌های دیگر	CPMG pulse sequence, spin-echo NMR	COSY NMR, 2D COSY, 1H-1H COSY	HSQC NMR, 1H-13C HSQC, heteronuclear correlation
مرتبط	4	4	4
خلاصه	The spin-echo is a fundamental nuclear magnetic resonance (NMR) pulse sequence technique introduced by Erwin Hahn in 1950. It uses a 90-degree radiofrequency pulse followed by a 180-degree refocusing pulse to create an echo, effectively reversing the effects of magnetic field inhomogeneities and allowing accurate measurement of spin relaxation properties. This technique is essential in modern NMR spectroscopy for both one-dimensional and multidimensional experiments.	Correlation Spectroscopy (COSY) is a two-dimensional NMR technique that correlates proton chemical shifts through scalar coupling (J-coupling), revealing which protons are magnetically coupled and hence bonded through multiple bonds. Developed by Aue, Bartholdi, and Ernst in 1976, COSY became one of the most important tools in structural elucidation, enabling chemists to map out proton connectivity patterns and deduce molecular topology without isotopic labeling.	Heteronuclear Single-Quantum Coherence (HSQC) is a 2D NMR technique that correlates proton and carbon-13 (or other heteronuclei) chemical shifts through one-bond coupling constants (1JHX). Developed in the early 1980s, HSQC rapidly became the workhorse of structural chemistry because it directly maps which carbons bear which protons, providing a comprehensive view of carbon skeleton connectivity and substitution patterns.