i like this post (click again to cancel)
i dont like this post (click again to cancel) remove favorite mark from this question (click again to restore mark)

How to set up the experiment in order to obtain a good COSY spectrum of Cu(II) compound?

I have tried to do it by just changing the spectrum width of both dimension, with an hour of acquistion time, but no cross peak can be observed between any signal.


asked May 21 '13 at 23:07

Kiu%20Chor%20Sham's gravatar image

Kiu Chor Sham

How broad are the peaks in the corresponding 1D NMR spectrum? - Pascal Fricke (May 22 '13 at 02:43)

One Answer:
i like this answer (click again to cancel)
i dont like this answer (click again to cancel)

In the canonical implementations of COSY, the cross-peaks are antiphase. In the presence of line-broadening, loss of signal intensity occurs due to the overlap of the components of the cross-peaks, which are of opposite sign in antiphase cross-peaks.

This problem may be overcome by use of modifications of the pulse sequence that produce a COSY spectrum with inphase and absorptive cross-peaks, if J/v is sufficiently large (J: coupling constant; v=line width).

A few relevant references are given below:

COSY with in-phase cross peaks. S Talluri, HA Scheraga. Journal of Magnetic Resonance 86 (1), 1-10, 1990.

Applications of COSY to paramagnetic heme-containing systems Ivano Bertini?, Francesco Capozza†, Claudio Luchinat†, Paola Turano? Journal of Magnetic Resonance. Volume 95, Issue 2, November 1991, Pages 244–252

Applications of COSY to paramagnetic heme-containing systems I Bertini, F Capozza, C Luchinat, P Turano - Journal of Magnetic …, 1991 - Elsevier

Frontiers in 2D NMR of paramagnetic metalloproteins L Banci, I Bertini, C Luchinat, L Messori… - Applied Magnetic …, 1993 - Springer

IP?COSY, a totally in?phase and sensitive COSY experiment Y Xia, G Legge, KY Jun, Y Qi, H Lee… - Magnetic Resonance in …, 2005


answered May 25 '13 at 12:57

sekhar%20Talluri's gravatar image

sekhar Talluri

Your answer
Please start posting your answer anonymously - your answer will be saved within the current session and published after you log in or create a new account. Please try to give a good answer, for discussions, please use comments and please do remember to vote (login to vote)
toggle preview

powered by CNPROG