{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

NMR Midterm Solns

NMR Midterm Solns - o 15 x 1 2 Beginning with Pulse 90 on N...

This preview shows page 1. Sign up to view the full content.

NMR Midterm Sol’ns. 15. T 1 dictates how long it will take to re-establish thermal equilibrium after a pulse, so it determines the repetition rate (the time between experiments). T 2 indicates the lifetime of the FID, so it determines the acquisition time (sampling time). 16. To selectively excite (or invert) any single resonance, a longer pulse is required because it has a narrower excitation profile (the excitation profile of any pulse is given by its Fourier transform). 17. The solution is the same as the INEPT example from class, except that coherence is being transferred from a heteronucleus to 1 H instead of the other way around.
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: o 15 x 1 2 Beginning with Pulse 90 on N: This is followed by a j-coupling evolution period, which only effects the coherence term: cos( ) sin( ) assuming a perfect transfer ( z z z y y z x z x I S I S S J I S J I S ρ π τ = + =-= -+ = o 1 15 3 1 4 1 = ). 2 Then, simultaneous 90 pulses on H and N: This is followed by another j-coupling evolution period to refocus the new H coherence. cos( ) sin( ) assuming perfect refo y z y z x x J I S I S J I J I τ = =-= -1 cusing ( = , because the 2 coupling is between one pair of spins). J...
View Full Document

{[ snackBarMessage ]}

What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern