Compară metode

	COSY	HSQC	Secvența spin-echo (ecou de spin)
Domeniu	Spectroscopie	Spectroscopie	Spectroscopie
Familie	Process / pipeline	Process / pipeline	Process / pipeline
Anul apariției	1976	1980	1950
Autorul original	Wüthrich Kurt	Anil Kumar	Erwin Hahn
Tip	Two-dimensional pulse sequence	Heteronuclear correlation sequence	Spectroscopic pulse sequence
Sursa seminală	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.	Hahn, E. L. (1950). Spin echoes. Physical Review, 80(4), 580-594.
Denumiri alternative	COSY NMR, 2D COSY, 1H-1H COSY	HSQC NMR, 1H-13C HSQC, heteronuclear correlation	CPMG pulse sequence, spin-echo NMR
Înrudite	4	4	4
Rezumat	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.	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.