Which of the following is not true regarding ¹H NMR spectroscopy? A) "shielding" leads to peaks at lower values of δ B) a "downfield" peak appears at a higher value of δ C) δ for a particular proton depends on the magnetic field strength of the instrument used. D) on a 300 MHz instrument, a proton that adsorbs irradiation at a frequency 1200 Hz higher than the adsorption of TMS appears at δ 4 ppm.

Question

Quizplus · Accepted Answer

C) is incorrect because δ (chemical shift) values are independent of the magnetic field strength of the NMR instrument. Chemical shifts are reported in parts per million (ppm) and are relative to a standard (usually TMS, tetramethylsilane), making them independent of the instrument's field strength.

Which of the Following Is Not True Regarding 1H NMR

Which of the Following Is Not True Regarding ¹H NMR