NMR Theories - Revision history

Milllo at 12:16, 12 May 2020

2020-05-12T12:16:49Z

2020-04-15T01:15:54Z

2020-03-20T04:26:27Z

2020-03-17T21:12:24Z

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← Older revision		Revision as of 12:16, 12 May 2020
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	* [[NMR of solids]] - it is still fundamentally NMR, but the technical challenges of having a solid vs a liquid need a whole section to describe the theory		* [[NMR of solids]] - it is still fundamentally NMR, but the technical challenges of having a solid vs a liquid need a whole section to describe the theory
		+
		+	==External Resources==
		+	There are many sites that still give good summaries of NMR theory, but they are disappearing fast. Latest link Check May 2020

← Older revision		Revision as of 01:15, 15 April 2020
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−	There are two main ways that these facts can be explained: One way looks at the absorbance of photons by atomic nuclei, while the other looks at induction by the magnetic fields of a sample.	+	There are two main ways that these facts can be explained: One way looks at the absorbance of photons by atomic nuclei, while the other looks at induction by the magnetic fields of a sample. Unfortunately, the NMR community mixes up the two ways, using whatever viewpoint is the most convenient for each aspect of the technique. This is extremely confusing since the theories are so different. This wiki will try to keep the two theoretical viewpoints separate yet still explain all aspects of NMR.

	==List of topics in this section==		==List of topics in this section==

← Older revision		Revision as of 04:26, 20 March 2020
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−	There are two main ways that these facts can be explained: One way looks at the absorbance of photons by atomic nuclei, while the other looks at ~~absorption of rf energy~~ by the magnetic fields of a sample.	+	There are two main ways that these facts can be explained: One way looks at the absorbance of photons by atomic nuclei, while the other looks at induction by the magnetic fields of a sample.

	==List of topics in this section==		==List of topics in this section==

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-Any successful theory must explain the observed facts. In NMR the fact is that when a sample of ethanol is placed in the center of a strong magnetic field and pulsed with a narrow band of a specific radio frequency energy (rf), a reproduceable spectrum of peaks will be produced. This spectrum has the following properties that must be explained:
+Any successful theory must explain the observed facts. In NMR the fact is that when a sample of a molecule such as ethanol is placed in the center of a strong magnetic field and pulsed with a narrow band of a specific radio frequency energy (rf), a reproduceable spectrum of peaks will be produced. This spectrum has the following properties that must be explained:
 # only hydrogens are seen when hydrogen settings are used for the rf
 # there are only three peaks

@@ Line 1: / Line 1: @@
-Any successful theory must explain the observed facts. In NMR the fact is that when a sample of ethanol placed in the center of a strong magnetic field and pulsed with a narrow band of a specific radio frequency energy (rf), a reproduceable spectrum of peaks will be produced. This spectrum has the following properties that must be explained:
+Any successful theory must explain the observed facts. In NMR the fact is that when a sample of ethanol is placed in the center of a strong magnetic field and pulsed with a narrow band of a specific radio frequency energy (rf), a reproduceable spectrum of peaks will be produced. This spectrum has the following properties that must be explained:
 # only hydrogens are seen when hydrogen settings are used for the rf
 # there are only three peaks

@@ Line 2: / Line 2: @@
 # only hydrogens are seen
 # there are only three peaks
-# the areas under the peaks are directly proportional to the concentrations of the hydrogens in ethanol i.e. the areas are 3:2:1
+# the areas under the peaks are directly proportional to the concentrations of the hydrogens in ethanol (i.e. the areas are 3:2:1)
 # two of the peaks are split into multiplets, while the third is a singlet
 # the intensity of the spectrum depends on the power of the rf pulse

← Older revision		Revision as of 17:33, 16 March 2020
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	# the sizes of the multiplets do not change with the strength of the magnetic field		# the sizes of the multiplets do not change with the strength of the magnetic field

−	~~There are two main ways to look at NMR. One way looks at the absorbance of photons by atomic nuclei. The other looks at absorption of rf energy by a sample.~~

		+	There are two main ways that these facts can be explained: One way looks at the absorbance of photons by atomic nuclei, while the other looks at absorption of rf energy by the magnetic fields of a sample.

	==List of topics in this section==		==List of topics in this section==