Electron Spin Resonance (ESR) - Revision history

Cmditradmin: /* Operation */

2011-11-08T18:52:32Z

Operation

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	{{#ev:youtube\|KOnodnj8a_8}}		{{#ev:youtube\|KOnodnj8a_8}}

	<embed_document width="55%" height="400">images/6/68/Esr.pdf</embed_document>		<embed_document width="100%" height="400">images/6/68/Esr.pdf</embed_document>

	=== External Links ===		=== External Links ===

Cmditradmin: /* Operation */

2011-11-08T18:52:16Z

Operation

← Older revision		Revision as of 11:52, 8 November 2011
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	=== Operation ===		=== Operation ===
	{{#ev:youtube\|KOnodnj8a_8}}		{{#ev:youtube\|KOnodnj8a_8}}

			<embed_document width="55%" height="400">images/6/68/Esr.pdf</embed_document>

	=== External Links ===		=== External Links ===

Cmditradmin: /* Operation */

2010-11-29T22:57:11Z

Operation

← Older revision		Revision as of 15:57, 29 November 2010
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	=== Operation ===		=== Operation ===
	{{#ev:youtube\|~~TAA_QokKEt0~~}}		{{#ev:youtube\|KOnodnj8a_8}}

	=== External Links ===		=== External Links ===

Cmditradmin: /* Background */

2010-11-18T23:33:29Z

Background

← Older revision		Revision as of 16:33, 18 November 2010
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	=== Background ===		=== Background ===
			[[Image:Epr splitting.png\|thumb\|300px\|Increasing magnetic field causes the spin states of electrons to be split ]]
	'''Electron Spin Resonance''' (ESR) also known as Electron Paramagnetic Resonance (EPR) spectroscopy or electron paramagnetic resonance spectroscopy is a technique for studying chemical species that have one or more unpaired electrons such as free radicals, odd electron molecules, transition metal complexes, lanthanide ions, and triplet state molecules. It is analogous to NMR except it deals with spins of electrons rather than the spins of atomic nuclei. It is most useful in studying free radicals or organic complexes having transition metal ions since most stable molecules have all their electrons paired. Most ESR spectra are recorded and published as first derivatives of the original signal.		'''Electron Spin Resonance''' (ESR) also known as Electron Paramagnetic Resonance (EPR) spectroscopy or electron paramagnetic resonance spectroscopy is a technique for studying chemical species that have one or more unpaired electrons such as free radicals, odd electron molecules, transition metal complexes, lanthanide ions, and triplet state molecules. It is analogous to NMR except it deals with spins of electrons rather than the spins of atomic nuclei. It is most useful in studying free radicals or organic complexes having transition metal ions since most stable molecules have all their electrons paired. Most ESR spectra are recorded and published as first derivatives of the original signal.

Cmditradmin: /* Significance */

2010-11-18T22:41:49Z

Significance

← Older revision		Revision as of 15:41, 18 November 2010
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	In a standard ESR experiment, the sample is irradiated with the microwave field at the constant frequency (~10GHz), the external magnetic field is slowly changed. Electron spins align with the field, but also can precess around the equilibrium orientation		In a standard ESR experiment, the sample is irradiated with the microwave field at the constant frequency (~10GHz), the external magnetic field is slowly changed. Electron spins align with the field, but also can precess around the equilibrium orientation

	The frequency of the spin precession depends on the field, it increases (linearly in a simple case) with the field increasing. When the field passes through the point, where the spin precession frequency corresponds to the microwave frequency applied, the sample will absorb microwave radiation ~~( and the electron spin flips from orientation spin-down to spin-up)~~.		The frequency of the spin precession depends on the field, it increases (linearly in a simple case) with the field increasing. When the field passes through the point, where the spin precession frequency corresponds to the microwave frequency applied, the sample will absorb microwave radiation.

	In pulsed ESR a strong burst of microwave energy is applied and a complex signal is recorded. This is analyzed through fourier transform to yield an ESR spectrum in the frequency domain.		In pulsed ESR a strong burst of microwave energy is applied and a complex response signal or transient signal is recorded. This is analyzed through fourier transform to yield an ESR spectrum in the frequency domain.

Cmditradmin: /* Operation */

2010-11-16T17:04:32Z

Operation

← Older revision		Revision as of 10:04, 16 November 2010
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	=== Operation ===		=== Operation ===
	{{#ev:youtube\|~~CYVaTsqMWII~~}}		{{#ev:youtube\|TAA_QokKEt0}}

	=== External Links ===		=== External Links ===

Cmditradmin: /* Significance */

2010-11-10T17:37:41Z

Significance

← Older revision		Revision as of 10:37, 10 November 2010
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	In a standard ESR experiment, the sample is irradiated with the microwave field at the constant frequency (~10GHz), the external magnetic field is slowly changed. Electron spins align with the field, but also can precess around the equilibrium orientation		In a standard ESR experiment, the sample is irradiated with the microwave field at the constant frequency (~10GHz), the external magnetic field is slowly changed. Electron spins align with the field, but also can precess around the equilibrium orientation

	The frequency of the spin precession depends on the field, it increases (linearly in a simple case) with the field increasing. When the field passes through the point, where the spin precession frequency corresponds to the microwave frequency applied, the sample will absorb microwave radiation ( and the electron spin flips from orientation spin-down to spin-up)		The frequency of the spin precession depends on the field, it increases (linearly in a simple case) with the field increasing. When the field passes through the point, where the spin precession frequency corresponds to the microwave frequency applied, the sample will absorb microwave radiation ( and the electron spin flips from orientation spin-down to spin-up).

			In pulsed ESR a strong burst of microwave energy is applied and a complex signal is recorded. This is analyzed through fourier transform to yield an ESR spectrum in the frequency domain.

Cmditradmin: /* External Links */

2010-11-10T17:24:24Z

External Links

← Older revision		Revision as of 10:24, 10 November 2010
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	[http://web.nmsu.edu/~snsm/classes/chem435/Lab7/ NMSU Spectroscopy Lab]		[http://web.nmsu.edu/~snsm/classes/chem435/Lab7/ NMSU Spectroscopy Lab]

			[http://www.bruker-biospin.com/cw.html Bruker ESR explanation]

Cmditradmin: /* External Links */

2010-11-10T16:55:14Z

External Links

← Older revision		Revision as of 09:55, 10 November 2010
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	=== External Links ===		=== External Links ===
	[[wikipedia:Electron_paramagnetic_resonance]]		[[wikipedia:Electron_paramagnetic_resonance]]
	[[http://web.nmsu.edu/~snsm/classes/chem435/Lab7/ NMSU Spectroscopy Lab]]
			[http://web.nmsu.edu/~snsm/classes/chem435/Lab7/ NMSU Spectroscopy Lab]

Cmditradmin: /* External Links */

2010-11-10T16:55:01Z

External Links

← Older revision		Revision as of 09:55, 10 November 2010
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	=== External Links ===		=== External Links ===
	~~see~~ [[wikipedia:Electron_paramagnetic_resonance]]		[[wikipedia:Electron_paramagnetic_resonance]]
			[[http://web.nmsu.edu/~snsm/classes/chem435/Lab7/ NMSU Spectroscopy Lab]]