Home >
Community >
How can I calculate the HOMO/LUMO energy from Cyclic Voltammetry data?
Upvote
41
Downvote
+ Homo-lumo
+ Chemistry
+ Cyclic voltammetry
Posted by
Larry Tracy
How can I calculate the HOMO/LUMO energy from Cyclic Voltammetry data?
You can do this relatively easily using cyclic voltammetry. The one thing you need to do is to use a reference material (or electrode), such as ferrocene. Once you perform the CV and rescale the potential to be vs. that reference system (you assume that the redox potential of your reference is equal to 0.0V), find the onset potential (Eox) of the first oxidation peak of your investigated species. Do the same for the onset potential of your first reduction peak (Ered). At this point, it is best to find the values separately in two experiments, as the products of oxidation/reduction will likely undergo reduction/oxidation closer to neutral potentials than your species will, obscuring your true onset potential. Once you have the two onset potentials (let us assume you are using the ferrocene redox pair as reference), the following empirical equations can be used: HOMO = 4.8 + Eox(vs.ferrocene) [eV] LUMO = 4.8 + Ered(vs. ferrocene) [eV] The experimental constant reported for ferrocene redox is -4.8eV (I have seen them reported as -5.1eV, however).
You can do this relatively easily using cyclic voltammetry. The one thing you need to do is to use a reference material (or electrode), such as ferrocene. Once you perform the CV and rescale the potential to be vs. that reference system (you assume that the redox potential of your reference is equal to 0.0V), find the onset potential (Eox) of the first oxidation peak of your investigated species. Do the same for the onset potential of your first reduction peak (Ered). At this point, it is best to find the values separately in two experiments, as the products of oxidation/reduction will likely undergo reduction/oxidation closer to neutral potentials than your species will, obscuring your true onset potential. Once you have the two onset potentials (let us assume you are using the ferrocene redox pair as reference), the following empirical equations can be used: HOMO = 4.8 + Eox(vs.ferrocene) [eV] LUMO = 4.8 + Ered(vs. ferrocene) [eV] The experimental constant reported for ferrocene redox is -4.8eV (I have seen them reported as -5.1eV, however).
you cannot do that using cyclic voltammetry , you can use GAUSSIAN program, using B3LYP functional and O3LYP methods with 6-31+G(d), 6-31G+(d,p) and 6-31+G(d,p) basis set. you can use cyclic Voltammetry in order to calculate number of electrons , No.of proton and study electro chemical behavior (oxidation reduction) , .......
you cannot do that using cyclic voltammetry , you can use GAUSSIAN program, using B3LYP functional and O3LYP methods with 6-31+G(d), 6-31G+(d,p) and 6-31+G(d,p) basis set. you can use cyclic Voltammetry in order to calculate number of electrons , No.of proton and study electro chemical behavior (oxidation reduction) , .......
Does changed the equation of calculation HOMO-LUMO energy by changing the solvent? My compounds are not soluble in Acetonitrile but soluble in DCM. if i do perform the cyclic voltammetry analysis in DCM solvent, then the equation will be same or not HOMO = 4.8 + Eox(vs.ferrocene) [eV] LUMO = 4.8 + Ered(vs. ferrocene) [eV]
Does changed the equation of calculation HOMO-LUMO energy by changing the solvent? My compounds are not soluble in Acetonitrile but soluble in DCM. if i do perform the cyclic voltammetry analysis in DCM solvent, then the equation will be same or not HOMO = 4.8 + Eox(vs.ferrocene) [eV] LUMO = 4.8 + Ered(vs. ferrocene) [eV]
You can do this relatively easily using cyclic voltammetry. The one thing you need to do is to use a reference material (or electrode), such as ferrocene. Once you perform the CV and rescale the potential to be vs. that reference system (you assume that the redox potential of your reference is equal to 0.0V), find the onset potential (Eox) of the first oxidation peak of your investigated species. Do the same for the onset potential of your first reduction peak (Ered). At this point, it is best to find the values separately in two experiments, as the products of oxidation/reduction will likely undergo reduction/oxidation closer to neutral potentials than your species will, obscuring your true onset potential. Once you have the two onset potentials (let us assume you are using the ferrocene redox pair as reference), the following empirical equations can be used: HOMO = 4.8 + Eox(vs.ferrocene) [eV] LUMO = 4.8 + Ered(vs. ferrocene) [eV] The experimental constant reported for ferrocene redox is -4.8eV (I have seen them reported as -5.1eV, however).
You can do this relatively easily using cyclic voltammetry. The one thing you need to do is to use a reference material (or electrode), such as ferrocene. Once you perform the CV and rescale the potential to be vs. that reference system (you assume that the redox potential of your reference is equal to 0.0V), find the onset potential (Eox) of the first oxidation peak of your investigated species. Do the same for the onset potential of your first reduction peak (Ered). At this point, it is best to find the values separately in two experiments, as the products of oxidation/reduction will likely undergo reduction/oxidation closer to neutral potentials than your species will, obscuring your true onset potential. Once you have the two onset potentials (let us assume you are using the ferrocene redox pair as reference), the following empirical equations can be used: HOMO = 4.8 + Eox(vs.ferrocene) [eV] LUMO = 4.8 + Ered(vs. ferrocene) [eV] The experimental constant reported for ferrocene redox is -4.8eV (I have seen them reported as -5.1eV, however).
Tomasz Jarosz Hello, do you have any idea how about the experimental setup? For example if I have my material as a powder, how should I run my experiment? i.e., should I dissolve it and run CV?, .. its a porous coordination polymer... how could I find out which electrolyte to use? Thank you.
Tomasz Jarosz Hello, do you have any idea how about the experimental setup? For example if I have my material as a powder, how should I run my experiment? i.e., should I dissolve it and run CV?, .. its a porous coordination polymer... how could I find out which electrolyte to use? Thank you.
M. L. Gonzalez-Juarez : Regarding the form of the electroactive species that you want to investigate, it should be either in solution or in the form of a uniform coating (e.g. film) on your working electrode - any way that does not significantly hinder charge transfer between this species and the working electrode should be fine. Regarding the choice of solvent and supporting electrolyte, the only truly crucial consideration is that they should not show redox signals (and not be electroactive) in the range of potentials, in which you will be investigating your polymer. A porous polymer might be a bit tricky and require some measures to deal with its (possible) high electric resistance (not sure how easily it is soaked by your solvent and how easilyare gas bubbles removed from within), but essentially, you will want an electrolyte with relatively small ions. If you can provide a bit more details, I might be able to point you in a more specific direciton, but you might need to do some trial and error experiments to see what the best setup is.
M. L. Gonzalez-Juarez : Regarding the form of the electroactive species that you want to investigate, it should be either in solution or in the form of a uniform coating (e.g. film) on your working electrode - any way that does not significantly hinder charge transfer between this species and the working electrode should be fine. Regarding the choice of solvent and supporting electrolyte, the only truly crucial consideration is that they should not show redox signals (and not be electroactive) in the range of potentials, in which you will be investigating your polymer. A porous polymer might be a bit tricky and require some measures to deal with its (possible) high electric resistance (not sure how easily it is soaked by your solvent and how easilyare gas bubbles removed from within), but essentially, you will want an electrolyte with relatively small ions. If you can provide a bit more details, I might be able to point you in a more specific direciton, but you might need to do some trial and error experiments to see what the best setup is.
You can do this relatively easily using cyclic voltammetry. The one thing you need to do is to use a reference material (or electrode), such as ferrocene. Once you perform the CV and rescale the potential to be vs. that reference system (you assume that the redox potential of your reference is equal to 0.0V), find the onset potential (Eox) of the first oxidation peak of your investigated species. Do the same for the onset potential of your first reduction peak (Ered).
At this point, it is best to find the values separately in two experiments, as the products of oxidation/reduction will likely undergo reduction/oxidation closer to neutral potentials than your species will, obscuring your true onset potential.
Once you have the two onset potentials (let us assume you are using the ferrocene redox pair as reference), the following empirical equations can be used:
HOMO = 4.8 + Eox(vs.ferrocene) [eV]
LUMO = 4.8 + Ered(vs. ferrocene) [eV]
The experimental constant reported for ferrocene redox is -4.8eV (I have seen them reported as -5.1eV, however).
You might be interested in the following paper, as it details the procedure some more:
https://www.researchgate.net/publication/264269067
EDIT: Another freely available paper, this time giving the ferrocene value as -4.4eV:
https://www.scientificbulletin.upb.ro/rev_docs_arhiva/rezdd1_869282.pdf
You can do this relatively easily using cyclic voltammetry. The one thing you need to do is to use a reference material (or electrode), such as ferrocene. Once you perform the CV and rescale the potential to be vs. that reference system (you assume that the redox potential of your reference is equal to 0.0V), find the onset potential (Eox) of the first oxidation peak of your investigated species. Do the same for the onset potential of your first reduction peak (Ered).
At this point, it is best to find the values separately in two experiments, as the products of oxidation/reduction will likely undergo reduction/oxidation closer to neutral potentials than your species will, obscuring your true onset potential.
Once you have the two onset potentials (let us assume you are using the ferrocene redox pair as reference), the following empirical equations can be used:
HOMO = 4.8 + Eox(vs.ferrocene) [eV]
LUMO = 4.8 + Ered(vs. ferrocene) [eV]
The experimental constant reported for ferrocene redox is -4.8eV (I have seen them reported as -5.1eV, however).
You might be interested in the following paper, as it details the procedure some more:
https://www.researchgate.net/publication/264269067
EDIT: Another freely available paper, this time giving the ferrocene value as -4.4eV:
https://www.scientificbulletin.upb.ro/rev_docs_arhiva/rezdd1_869282.pdf
More
VOTE
you cannot do that using cyclic voltammetry , you can use GAUSSIAN program, using B3LYP functional and O3LYP methods with 6-31+G(d), 6-31G+(d,p) and 6-31+G(d,p) basis set. you can use cyclic Voltammetry in order to calculate number of electrons , No.of proton and study electro chemical behavior (oxidation reduction) , .......
you cannot do that using cyclic voltammetry , you can use GAUSSIAN program, using B3LYP functional and O3LYP methods with 6-31+G(d), 6-31G+(d,p) and 6-31+G(d,p) basis set. you can use cyclic Voltammetry in order to calculate number of electrons , No.of proton and study electro chemical behavior (oxidation reduction) , .......
More
VOTE
Does changed the equation of calculation HOMO-LUMO energy by changing the solvent? My compounds are not soluble in Acetonitrile but soluble in DCM. if i do perform the cyclic voltammetry analysis in DCM solvent, then the equation will be same or not
HOMO = 4.8 + Eox(vs.ferrocene) [eV]
LUMO = 4.8 + Ered(vs. ferrocene) [eV]
Does changed the equation of calculation HOMO-LUMO energy by changing the solvent? My compounds are not soluble in Acetonitrile but soluble in DCM. if i do perform the cyclic voltammetry analysis in DCM solvent, then the equation will be same or not
HOMO = 4.8 + Eox(vs.ferrocene) [eV]
LUMO = 4.8 + Ered(vs. ferrocene) [eV]
More
VOTE
You can do this relatively easily using cyclic voltammetry. The one thing you need to do is to use a reference material (or electrode), such as ferrocene. Once you perform the CV and rescale the potential to be vs. that reference system (you assume that the redox potential of your reference is equal to 0.0V), find the onset potential (Eox) of the first oxidation peak of your investigated species. Do the same for the onset potential of your first reduction peak (Ered).
At this point, it is best to find the values separately in two experiments, as the products of oxidation/reduction will likely undergo reduction/oxidation closer to neutral potentials than your species will, obscuring your true onset potential.
Once you have the two onset potentials (let us assume you are using the ferrocene redox pair as reference), the following empirical equations can be used:
HOMO = 4.8 + Eox(vs.ferrocene) [eV]
LUMO = 4.8 + Ered(vs. ferrocene) [eV]
The experimental constant reported for ferrocene redox is -4.8eV (I have seen them reported as -5.1eV, however).
You might be interested in the following paper, as it details the procedure some more:
https://www.researchgate.net/publication/264269067
EDIT: Another freely available paper, this time giving the ferrocene value as -4.4eV:
https://www.scientificbulletin.upb.ro/rev_docs_arhiva/rezdd1_869282.pdf
You can do this relatively easily using cyclic voltammetry. The one thing you need to do is to use a reference material (or electrode), such as ferrocene. Once you perform the CV and rescale the potential to be vs. that reference system (you assume that the redox potential of your reference is equal to 0.0V), find the onset potential (Eox) of the first oxidation peak of your investigated species. Do the same for the onset potential of your first reduction peak (Ered).
At this point, it is best to find the values separately in two experiments, as the products of oxidation/reduction will likely undergo reduction/oxidation closer to neutral potentials than your species will, obscuring your true onset potential.
Once you have the two onset potentials (let us assume you are using the ferrocene redox pair as reference), the following empirical equations can be used:
HOMO = 4.8 + Eox(vs.ferrocene) [eV]
LUMO = 4.8 + Ered(vs. ferrocene) [eV]
The experimental constant reported for ferrocene redox is -4.8eV (I have seen them reported as -5.1eV, however).
You might be interested in the following paper, as it details the procedure some more:
https://www.researchgate.net/publication/264269067
EDIT: Another freely available paper, this time giving the ferrocene value as -4.4eV:
https://www.scientificbulletin.upb.ro/rev_docs_arhiva/rezdd1_869282.pdf
More
VOTE
I think you cannot do that using cyclic. You need a software
http://www.jmaterenvironsci.com/Document/vol1/10-JMES-15-2010-bouachrine.pdf
I think you cannot do that using cyclic. You need a software
http://www.jmaterenvironsci.com/Document/vol1/10-JMES-15-2010-bouachrine.pdf
More
VOTE
Tomasz Jarosz Hello, do you have any idea how about the experimental setup? For example if I have my material as a powder, how should I run my experiment? i.e., should I dissolve it and run CV?, .. its a porous coordination polymer... how could I find out which electrolyte to use?
Thank you.
Tomasz Jarosz Hello, do you have any idea how about the experimental setup? For example if I have my material as a powder, how should I run my experiment? i.e., should I dissolve it and run CV?, .. its a porous coordination polymer... how could I find out which electrolyte to use?
Thank you.
More
VOTE
M. L. Gonzalez-Juarez : Regarding the form of the electroactive species that you want to investigate, it should be either in solution or in the form of a uniform coating (e.g. film) on your working electrode - any way that does not significantly hinder charge transfer between this species and the working electrode should be fine.
Regarding the choice of solvent and supporting electrolyte, the only truly crucial consideration is that they should not show redox signals (and not be electroactive) in the range of potentials, in which you will be investigating your polymer. A porous polymer might be a bit tricky and require some measures to deal with its (possible) high electric resistance (not sure how easily it is soaked by your solvent and how easilyare gas bubbles removed from within), but essentially, you will want an electrolyte with relatively small ions.
If you can provide a bit more details, I might be able to point you in a more specific direciton, but you might need to do some trial and error experiments to see what the best setup is.
M. L. Gonzalez-Juarez : Regarding the form of the electroactive species that you want to investigate, it should be either in solution or in the form of a uniform coating (e.g. film) on your working electrode - any way that does not significantly hinder charge transfer between this species and the working electrode should be fine.
Regarding the choice of solvent and supporting electrolyte, the only truly crucial consideration is that they should not show redox signals (and not be electroactive) in the range of potentials, in which you will be investigating your polymer. A porous polymer might be a bit tricky and require some measures to deal with its (possible) high electric resistance (not sure how easily it is soaked by your solvent and how easilyare gas bubbles removed from within), but essentially, you will want an electrolyte with relatively small ions.
If you can provide a bit more details, I might be able to point you in a more specific direciton, but you might need to do some trial and error experiments to see what the best setup is.
More
VOTE