两道关于NMR的题!

futurex888UID: 2134758

The intensity of an isolated peak in a broadband proton decoupled 13C
spectrum may not reflect the number of carbons giving rise to that
signal.
In order to successfully integrate carbon signals one should:

(a)                Give up: 13C NMR is not quantitative and spectra cannot be
integrated.

(b)                Switch off the decoupler.

(c)                Use a pulse delay of 5 times the longest T1

(d)                Use a pulse delay of 5 times the longest T1 and switch off the
decoupler.



The 300 MHz 1H NMR spectrum of a compound containing an AX spin-system
shows peaks at 10, 20, 145 and 155 Hz
from the methyl resonance of tetramethylsilane (TMS).
At what frequencies would these lines appear in a 600 MHz spectrum?

(a)                The spectrometer is locked to TMS so the values remain the same.

(b)                20, 40, 290 and 310 Hz from TMS

(c)                5, 10, 72.5 and 77.5 Hz from TMS.

(d)                25, 35, 295 and 305 Hz from TMS.

答案应该是什么啊?为什么?

一定要告诉我为什么!多谢多谢!

再次感谢!:handshake

futurex888UID: 2134758

自己搞定了......:victory: