Donors and Acceptors - Revision history

Cmditradmin at 19:28, 29 December 2009

2009-12-29T19:28:26Z

← Older revision		Revision as of 12:28, 29 December 2009
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	*Finally in case 4 the donor and acceptor are equal, it now looks like butadiene.		*Finally in case 4 the donor and acceptor are equal, it now looks like butadiene.
	<embed_document width="55%" height="400">http://depts.washington.edu/cmditr/media/ethyltemp.pdf</embed_document>		<embed_document width="55%" height="400">http://depts.washington.edu/cmditr/media/ethyltemp.pdf</embed_document>
			[[category:molecular orbitals]]
	<table id="toc" style="width: 100%">		<table id="toc" style="width: 100%">
	<tr>		<tr>

Cmditradmin at 22:09, 27 August 2009

2009-08-27T22:09:17Z

← Older revision		Revision as of 15:09, 27 August 2009
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	First to be fair we should compare orbitals with equal occupancy and if we compared CH<sub>3</sub>O and (CH<sub>3</sub>)<sub>2</sub>N to (CH<sub>3</sub>)<sub>2</sub>C<sup>–</sup> we would think that the carbanion was a better donor than the methoxy group or the amino group.		First to be fair we should compare orbitals with equal occupancy and if we compared CH<sub>3</sub>O and (CH<sub>3</sub>)<sub>2</sub>N to (CH<sub>3</sub>)<sub>2</sub>C<sup>–</sup> we would think that the carbanion was a better donor than the methoxy group or the amino group.
	<br clear='all'>		<br clear='all'>


			=== Effect of adding donors and acceptors ===

	[[Image:Donoracceptorcases.png\|thumb\|200px\|Molecular orbitals of ethylene with added donor or acceptor groups]]		[[Image:Donoracceptorcases.png\|thumb\|200px\|Molecular orbitals of ethylene with added donor or acceptor groups]]

Cmditradmin at 22:06, 27 August 2009

2009-08-27T22:06:39Z

← Older revision		Revision as of 15:06, 27 August 2009
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			=== Donor / Acceptor Defined ===

	[[Image:Donoracceptor.png\|thumb\|300px\|Electrons eventually end up in the lowest energy level relative to the reference level.]]		[[Image:Donoracceptor.png\|thumb\|300px\|Electrons eventually end up in the lowest energy level relative to the reference level.]]
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	*An acceptor is an atom or group of atoms whose lowest unfilled atomic or molecular orbital is lower in energy than that of a reference orbital.		*An acceptor is an atom or group of atoms whose lowest unfilled atomic or molecular orbital is lower in energy than that of a reference orbital.

			=== Reference orbitals ===

	Why do we use reference orbital?		Why do we use reference orbital?
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	First to be fair we should compare orbitals with equal occupancy and if we compared CH<sub>3</sub>O and (CH<sub>3</sub>)<sub>2</sub>N to (CH<sub>3</sub>)<sub>2</sub>C<sup>–</sup> we would think that the carbanion was a better donor than the methoxy group or the amino group.		First to be fair we should compare orbitals with equal occupancy and if we compared CH<sub>3</sub>O and (CH<sub>3</sub>)<sub>2</sub>N to (CH<sub>3</sub>)<sub>2</sub>C<sup>–</sup> we would think that the carbanion was a better donor than the methoxy group or the amino group.
	<br clear='all'>		<br clear='all'>

	[[Image:Donoracceptorcases.png\|thumb\|200px\|Molecular orbitals of ethylene with added donor or acceptor groups]]		[[Image:Donoracceptorcases.png\|thumb\|200px\|Molecular orbitals of ethylene with added donor or acceptor groups]]
	Consider what happens to the molecular orbitals of ethylene when we attach donors or acceptor groups to them.		Consider what happens to the molecular orbitals of ethylene when we attach donors or acceptor groups to them.

Cmditradmin: /* Donor and Acceptor on Ethylene */

2009-08-24T22:45:04Z

Donor and Acceptor on Ethylene

← Older revision		Revision as of 15:45, 24 August 2009
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	The same arguments will hold in reverse for the acceptor case. The LUMO is going to go down, and become easier to reduce. Adding an amine makes it easier to oxidize and decreases the gap.		The same arguments will hold in reverse for the acceptor case. The LUMO is going to go down, and become easier to reduce. Adding an amine makes it easier to oxidize and decreases the gap.

			<br clear='all'>
	=== Donor and Acceptor on Ethylene ===		=== Donor and Acceptor on Ethylene ===
	Consider this series in which two orbitals like ethylene behave as donor and acceptor.		Consider this series in which two orbitals like ethylene behave as donor and acceptor.

Cmditradmin at 22:44, 24 August 2009

2009-08-24T22:44:32Z

← Older revision		Revision as of 15:44, 24 August 2009
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	First to be fair we should compare orbitals with equal occupancy and if we compared CH<sub>3</sub>O and (CH<sub>3</sub>)<sub>2</sub>N to (CH<sub>3</sub>)<sub>2</sub>C<sup>–</sup> we would think that the carbanion was a better donor than the methoxy group or the amino group.		First to be fair we should compare orbitals with equal occupancy and if we compared CH<sub>3</sub>O and (CH<sub>3</sub>)<sub>2</sub>N to (CH<sub>3</sub>)<sub>2</sub>C<sup>–</sup> we would think that the carbanion was a better donor than the methoxy group or the amino group.
			<br clear='all'>
	[[Image:Donoracceptorcases.png\|thumb\|200px\|Molecular orbitals of ethylene with added donor or acceptor groups]]		[[Image:Donoracceptorcases.png\|thumb\|200px\|Molecular orbitals of ethylene with added donor or acceptor groups]]
	Consider what happens to the molecular orbitals of ethylene when we attach donors or acceptor groups to them.		Consider what happens to the molecular orbitals of ethylene when we attach donors or acceptor groups to them.

Cmditradmin at 20:47, 10 June 2009

2009-06-10T20:47:10Z

← Older revision		Revision as of 13:47, 10 June 2009
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	First to be fair we should compare orbitals with equal occupancy and if we compared CH<sub>3</sub>O and (CH<sub>3</sub>)<sub>2</sub>N to (CH<sub>3</sub>)<sub>2</sub>C<sup>–</sup> we would think that the carbanion was a better donor than the methoxy group or the amino group.		First to be fair we should compare orbitals with equal occupancy and if we compared CH<sub>3</sub>O and (CH<sub>3</sub>)<sub>2</sub>N to (CH<sub>3</sub>)<sub>2</sub>C<sup>–</sup> we would think that the carbanion was a better donor than the methoxy group or the amino group.

	[[Image:Donoracceptorcases.png\|thumb\|200px\|]]		[[Image:Donoracceptorcases.png\|thumb\|200px\|Molecular orbitals of ethylene with added donor or acceptor groups]]
	Consider what happens to the molecular orbitals of ethylene when we attach donors or acceptor groups to them.		Consider what happens to the molecular orbitals of ethylene when we attach donors or acceptor groups to them.

Cmditradmin at 20:44, 10 June 2009

2009-06-10T20:44:35Z

← Older revision		Revision as of 13:44, 10 June 2009
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	[[Image:Donoracceptor.png\|thumb\|300px\|]]		[[Image:Donoracceptor.png\|thumb\|300px\|Electrons eventually end up in the lowest energy level relative to the reference level.]]
	A donor is a high energy orbital with one or more electrons		A donor is a high energy orbital with one or more electrons.
	An acceptor is a low energy orbital with one or more vacancies:		An acceptor is a low energy orbital with one or more vacancies:

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	Why do we use reference orbital?		Why do we use reference orbital?

	~~Because the~~ driving force for an electron in an orbital to be transferred (donated) to another orbital (an acceptor orbital) is related to the difference in energy between the ~~orbital~~ not the absolute energy.		The driving force for an electron in an orbital to be transferred (donated) to another orbital (an acceptor orbital) is related to the difference in energy between the orbitals not the absolute energy.

	In the diagram in each case the electron will end up on the lowest relative energy level. In organic chemistry we often think of CH<sub>3</sub>O and (CH<sub>3</sub>)<sub>2</sub>N as donors even though nitrogen and oxygen are more electronegative than carbon (i.e. their orbital are lower in energy than carbon?		In the diagram in each case the electron will end up on the lowest relative energy level. In organic chemistry we often think of CH<sub>3</sub>O and (CH<sub>3</sub>)<sub>2</sub>N as donors even though nitrogen and oxygen are more electronegative than carbon (i.e. their orbital are lower in energy than carbon?
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	*The HOMO-LUMO energy gap is now smaller.		*The HOMO-LUMO energy gap is now smaller.

	The same arguments will hold in reverse for the acceptor case. The ~~Lumo~~ is going to go down, and become easier to reduce. Adding an amine makes it easier to oxidize and decreases the gap.		The acceptor case:

			The same arguments will hold in reverse for the acceptor case. The LUMO is going to go down, and become easier to reduce. Adding an amine makes it easier to oxidize and decreases the gap.

	=== Donor and Acceptor on Ethylene ===		=== Donor and Acceptor on Ethylene ===

Cmditradmin: /* Donor and Acceptor on Ethylene */

2009-06-02T20:11:23Z

Donor and Acceptor on Ethylene

← Older revision		Revision as of 13:11, 2 June 2009
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	=== Donor and Acceptor on Ethylene ===		=== Donor and Acceptor on Ethylene ===
	Consider this series in which two orbitals like ethylene ~~with a~~ donor and an acceptor.		Consider this series in which two orbitals like ethylene behave as donor and acceptor.
	*In the first case the donor orbital is very low energy and the acceptor is very high energy. As a result there is little mixing. It looks mostly like a bridge orbital. There is little dipole moment.		*In the first case the donor orbital is very low energy and the acceptor is very high energy. As a result there is little mixing. It looks mostly like a bridge orbital. There is little dipole moment.
	*If we make the donor stronger there is more mixing and the donor begins to have coefficient and the bridge has coefficient. There is more of dipole moment and some redistribution of charge.		*If we make the donor stronger there is more mixing and the donor begins to have coefficient and the bridge has coefficient. There is more of dipole moment and some redistribution of charge.

Cmditradmin at 23:18, 1 June 2009

2009-06-01T23:18:23Z

← Older revision		Revision as of 16:18, 1 June 2009
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	<table id="toc" style="width: 100%">		<table id="toc" style="width: 100%">
	<tr>		<tr>
	<td style="text-align: left; width: 33%">[[~~DElectronic~~ Coupling Between Orbitals\|Previous Topic]]</td>		<td style="text-align: left; width: 33%">[[Electronic Coupling Between Orbitals\|Previous Topic]]</td>
	<td style="text-align: center; width: 33%">[[Main_Page#Molecular Orbitals\|Return to Molecular Orbitals Menu]]</td>		<td style="text-align: center; width: 33%">[[Main_Page#Molecular Orbitals\|Return to Molecular Orbitals Menu]]</td>

Cmditradmin at 23:17, 1 June 2009

2009-06-01T23:17:58Z

← Older revision		Revision as of 16:17, 1 June 2009
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	<table id="toc" style="width: 100%">		<table id="toc" style="width: 100%">
	<tr>		<tr>
	<td style="text-align: left; width: 33%">[[~~Donors and Acceptors~~\|Previous Topic]]</td>		<td style="text-align: left; width: 33%">[[Electronic Coupling Between Orbitals\|Previous Topic]]</td>
	<td style="text-align: center; width: 33%">[[Main_Page#Molecular Orbitals\|Return to Molecular Orbitals Menu]]</td>		<td style="text-align: center; width: 33%">[[Main_Page#Molecular Orbitals\|Return to Molecular Orbitals Menu]]</td>

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	<table id="toc" style="width: 100%">		<table id="toc" style="width: 100%">
	<tr>		<tr>
	<td style="text-align: left; width: 33%">[[~~Donors and Acceptors~~\|Previous Topic]]</td>		<td style="text-align: left; width: 33%">[[DElectronic Coupling Between Orbitals\|Previous Topic]]</td>
	<td style="text-align: center; width: 33%">[[Main_Page#Molecular Orbitals\|Return to Molecular Orbitals Menu]]</td>		<td style="text-align: center; width: 33%">[[Main_Page#Molecular Orbitals\|Return to Molecular Orbitals Menu]]</td>