NMR Spektroskopisi ve Analiz Yöntemleri

Hello everybody, my name is Iman. Welcome back to my YouTube channel. Today we're continuing our lecture on spectroscopy. We are at the third objective, which is all about nuclear magnetic resonance spectroscopy, also known as NMR. Now NMR spectroscopy is based on the fact that certain atomic nuclei have magnetic moments that are oriented at random. And when such nuclei are placed in a magnetic field, their magnetic moments tend to align either with or against the direction of this applied field. Nuclei with magnetic moments that are aligned with the field are said to be in the alpha state, lower energy state. The nuclei can then be irradiated with radiofrequency pulses that match the energy gap between the two states, which will then excite some lower energy nuclei into the beta state or the higher energy state. The absorption of this radiation leads to excitation at different frequencies depending on the atom's magnetic environment. Now, let's break this down because that's a lot of information and maybe some of this terminology seems intimidating. So we're going to break this down and we're going to say that NMR spectroscopy explores the interaction between electromagnetic radiation and the magnetic moments of nuclei. So we're going to break this down by covering a couple of topics that we're going to use to build up this idea of NMR. This is going to be, first we're going to talk about magnetic moments and magnetic field alignment. Then we're going to talk about radio frequency irradiation and the energy gap. All right, we're going to call that EG for energy gap. Then we're going to talk about resonance and absorption, all right, and absorption. Then we'll talk about detection, all right, and that requires us to talk about NMR spectra. And then finally, with all this knowledge, we can move into talking about analysis, all right. And for analysis here, we're going to have to understand things like chemical. environment, all right, shielding amongst other things. All right, so that's our breakdown of how we want to talk about NMR spectroscopy to really understand it. Now, for the first topic, nuclear For magnetic moments and magnetic field alignment, nuclei of certain isotopes, they possess a property known as spin, which due to their charge generates a magnetic moment. So you can think about them as like a tiny bar magnet. Now when you take these nuclei and they're placed in a strong magnetic field. all right, when you place them in a strong magnetic field, all right, their magnetic moments align in one of two ways. They can align with the field. All right, they can align with the field. This is going to be the lower energy state, the alpha state, or they're going to align against the field, the higher energy state, the beta state. All right, now when we move into talking about radiofrequency, iridation, and energy gap, well, the energy difference between the alpha state and the beta state is very specific, and it depends on the strength of the external magnetic field and the type of nucleus. By applying radiofrequency pulses at a frequency that matches this energy gap, nuclei can then be excited from the alpha state to that beta state. And this then allows us to talk about resonance and absorption. When the frequency of the radiofrequency radiation corresponds to the energy gap, Resonance occurs and the nuclei absorb the radiofrequency energy transitioning to that higher energy state, all right? Then what happens, all right, is that after excitation, nuclei eventually release the absorbed energy and return to the lower energy state, a process that's known as relaxation. The release energy is detected and transformed into a state of relaxation. into NMR signal. All right, now we could talk about analysis, and this results in us talking about chemical environment and shielding as well. The exact frequency at which a nucleus resonates is affected by the electronic environment around it. Electrons can shield the nucleus from the external. magnetic field and different chemical environments are going to result in slightly different resonances, which is how NMR can distinguish between different types of atoms in a molecule. And then when we get to Actually discussing analysis and interpretation, the NMR spectrum consists of peaks that correspond to different nuclei resonating at different frequencies. And by analyzing those peaks, scientists can infer the chemical structure of the molecule. Looking at an NMR spectra, we can talk about several things that are going to help us understand this spectra. Those things are chemical shift. The position of an NMR signal on the spectrum is called the chemical shift, and it is highly sensitive to the chemical environment of the nucleus. We can also talk about integration. The area under an NMR peak reflects the number of nuclei that correspond to that signal. And then we can also talk about multiple structure. The splitting pattern of an NMR signal provides information about the number of neighboring nuclei. All right, so when we talk about NMR spectra, all right, a typical NMR spectra is a plot of frequency versus absorption of energy. And because different NMR spectrometers operate at different magnetic field strengths, a standardized method of plotting the NMR spectrum has been adopted. The standardized method, which is The only one that's seen on the MCAT and the only one that we're going to concern ourselves with uses an arbitrary variable called chemical shift, which with units of parts per million, all right, ppm. The chemical shift is plotted on the x-axis and it increases towards the left, which is referred to as downfield. To make sure that we know just how far downfield compounds are, we use tetramethylsilane, TMS, as the calibration standard to mark zero ppm. When counting peaks, make sure to skip that TMS peak. Now nuclear magnetic resonance. is most commonly used to study H nuclei, right? H1, hydrogen 1 nuclei, protons. And that is all that the MCAT will be testing for. So that is all that we are going to be concerning ourselves with. Now, here you can see things that you want to think about when you're looking at the spectra, number of signals, location of signals, area under signals, and the shape of the signals. We're going to be talking about these things. Here in this video, we're going to talk about chemical shifts, integration, and multiplicity and coupling. Again, I want to reiterate that for a more in-depth analysis of this flowchart to understand NMR, I would highly recommend my Organic Chemistry 2 playlist, Chapter 15 is all about NMR. Here, of course, in the video, we're going to hyper-focus on the concepts that are high-yield test concepts, and we're not going to concern ourselves with too much. theory that is unnecessary for the MCAT. So we're going to start off here with looking at this NMR spectra for dichloromethylmethyl ether, and we're going to talk about interpreting the HNMR spectra for this compound. All right, here we have it shown. All right, here we have it shown. Now, most hydrogen nuclei come into resonance anywhere between 0 to about 10 ppm downfield from that TMS peak. each distinct set of nuclei gives rise to a separate peak. This means that if multiple protons are chemically equivalent, meaning they have the same magnetic environment, they will lead to the same peak. So for example, if we look at this figure here, all right, it depicts the HNMR of dichloromethylmethyl ether, which has two distinct sets of hydrogen nuclei. While it has four hydrogens, it only has two distinct hydrogens. HA, this is the hydrogen that's attached to the carbon that has two chlorine groups. And this hydrogen, HB, that's attached to this carbon. All three of these hydrogens on this carbon are referred to as being chemically equivalent. They have the same magnetic environment. They are going to lead to the same peak. All right, so the single proton... Attached to the dichloromethyl group HA is in a different magnetic environment from the three protons on the methyl group HB. So the two classes will resonate at different frequencies. Now the three protons on the methyl group are chemically equivalent. They're going to resonate at the same frequency because this group rotates freely and on average each proton sees an identical magnetic environment. All right now the peak on the left all right this peak on the left right here I'm going to highlight it in blue. All right, it's referred to as A. This is from the single dichloromethyl proton. And then the taller middle peaks that I'm going to highlight here in red, referred to as B. All right, these are from the three methyl protons. Now, the height of each peak is proportional to the number of protons it contains. Specifically, if we were to analyze the area under the peaks, called the integration, we would find that the ratio of peak A to peak B is about 1 to 3, corresponding exactly to the ratio of protons that produce each peak. This makes sense. There is one hydrogen that is... associated to this dichloromethyl group, all right? And there are three equivalent HB protons. And that makes sense. When you integrate the A peak and then the B peak, you have this one-to-three ratio, and that's because there is one HA proton to three HB protons, all right? Now that we know which peak is which, let's talk about their respective positions on the spectrum. We can see that the peak for the single proton, the peak A, is fairly far downfield compared with the B peak. This is because it is attached to a carbon with two electronegative chlorine atoms and an oxygen. These atoms pull electron density away from the surrounding atoms, thus deshielding the proton. from the magnetic field. All right, the more the proton's electron density is pulled away, the less it can shield itself from the applied magnetic field, resulting in a further downfield reading. Now, with the same reasoning, we know that if we had an electron donating group, such as a silicon atom in TMS, it would help shield the H nuclei and give it a position further upfield. This is why tetramethylsilane is used as the reference or calibration peak. Everything else in proton NMR will be more deshielded than it. All right. Now, with that discussion, it becomes really important for us to talk about where we would expect certain features to appear in our NMR spectra. All right. And so here we see a table. indicating the chemical shift ranges of several different types of protons. Now, if I was your friend, I would give you the advice that it is probably beneficial to you to kind of have a good understanding of all of these groups and where they would appear. However, if you're on a time crunch or you want to know what the high yield things to know in regards to the chemical shifts for protons in different environments for NMR, here are those groups that you should know. The ones that are most important are going to be the aldehydes and ketones, all right? Make sure you know where you would see aldehydes on the NMR spectra, all right? Also, no carboxylic acid, okay? No aromatic rings where they would appear, all right? Also, different hybridized carbons. So know where a sp3 carbon would appear, an sp2 carbon would appear, and an sp carbon would appear. As well as the range for alcohols. And honestly, that pretty much encompasses everything that we're seeing here anyways. So really, all of these groups are extremely important to know. Now, once you have your chemical shifts, down, once you know where you would expect different features to be on your NMR spectra, and you understand how integration gives you this ratio relationship of different groups for the different peaks, the next thing that you want to talk about is multiplicity. In NMR, peaks tend to have distinct shapes called the peak multiplicity. Multiplicity, or in other words, coupling, is a view on the environment. that a hydrogen resides in. It reveals how many hydrogens are on the next carbon in the structure. So when you look at NMR, multiply Multiplicity is defined by the number of peaks in the signal. Two questions we should ask about these peaks and multiplicity are, one, why do we get multiplicity? What is the cause of this peak splitting we are observing? All right, and two, what does it mean? To answer the first question, a signal's multiplicity is the consequential result of the magnetic effects of neighboring hydrogens. And so then to answer the second question, what does it mean? It indicates the number of neighboring protons, and as a consequence, allows us to build an understanding of the framework of a molecule. Remember, we use HNMR to get the carbon-hydrogen framework because nuclei with odd number of protons have something called nuclear spin. and this means that the nuclei rotates and causes a magnetic field around itself called the magnetic moment. When there are other neighboring nuclei like that, the magnetic effects of each will interact with each other in a molecule. This signal's multiplicity is the result of the magnetic effects of neighboring protons and therefore indicates the number of neighboring protons. So to illustrate this concept, let's consider the following examples. All right, if you have a molecule like this, all right, and you have these two protons, HA, HB, if HA and HB are not equivalent to each other, they will produce different signals. Let's focus on HA. All right, let's focus on HA. In some molecules, all right, HB will be aligned with the field, while in other molecules, HB will be aligned against the field. As a result, the chemical shift of HA in some molecules will be slightly different than the chemical shift of HA in other molecules, resulting in the appearance of two peaks for HA. In other words, this presence of HB. B splits the signal for HA into a doublet. So HA will appear as a doublet in the NMR spectrum. All right, if you have this molecule now where you have HA here on this carbon and on this neighboring carbon, you have two hydrogens, HB hydrogens. All right, what would you expect? Well, you can have both of those HB protons that align against the field. both that align with the field, or you can have a mixture of align or not align for these HB protons. What that means is that these HB protons are going to split the signal for HA into a triplet. So HA appears as a triplet, all right, because of the splitting that's caused by these two HB protons, all right? And again, we can look at this one where there are... There's your HA signal that you're concerned with, and neighboring it is a carbon that has three HB protons. All three can align with the field, all three can align against the field, and you can have a mixture of align and not align. What happens here is that the presence of these three HB protons splits the signal for HA into a quartet. There is a very... clear pattern that's happening here. When you are looking at HA or any proton, all right, and you're trying to figure out its peak multiplicity based off of the number of neighboring protons, that is going to be equal to N plus 1. The peak multiplicity of HA is going to be equal to the number of neighboring protons, N plus 1. And so in this scenario, that's going to equal 2. Hence why we see that HA appears as a doublet, two peaks, two peak splits. All right, for this scenario, the HA peak is going to have N plus 1. It has two neighboring hydrogens. Then you add plus 1. That gives you a 3. Hence why we see HA appears as a triplet. And then again for this scenario, HA equals number of... proton neighbors, that's three for HB plus one, that gives you four. Hence why HA appears as a quartet in your NMR signal. All right, so the way to know what the multiplicity of a hydrogen is, is you can count the number of neighboring hydrogens, then add one. So if a hydrogen has three neighboring hydrogens, It's going to have a multiplicity of 3 plus 1, which is equal to 4. It's going to be a quartet. And so here we've talked about a lot of elements that we can put together to really understand NMR. All right. Knowing how many unique hydrogen signals you have and the chemical shift of each. Then you have integration. All right. And multiplicity. And all of these play a role into your NMR spectrum. All right, all of these are really important in reading and interpreting a NMR spectrum. All right, chemical shifts give you where you would expect to have a signal. All right. Integration is the area under the curve, and this is proportional to the number of protons contained under the peak. And then you have multiplicity, which gives you an understanding of your environment. How many neighboring hydrogens do you have that are interfering with your signal? That results in this signal splitting. All right. That's everything we need to know conceptually about NMR. And in the previous video, we did IR and UV. So now we've covered everything we need to know about spectroscopy for the MCAT. In the following video, we're going to tackle a practice problem set. Let me know if you have any questions, comments, concerns down below. Other than that, good luck, happy studying, and have a beautiful, beautiful day, future doctors.

Now NMR spectroscopy is based on the fact that certain atomic nuclei have magnetic moments that are oriented at random. And when such nuclei are placed in a magnetic field, their magnetic moments tend to align either with or against the direction of this applied field. Nuclei with magnetic moments that are aligned with the field are said to be in the alpha state, lower energy state.

The nuclei can then be irradiated with radiofrequency pulses that match the energy gap between the two states, which will then excite some lower energy nuclei into the beta state or the higher energy state. The absorption of this radiation leads to excitation at different frequencies depending on the atom's magnetic environment. Now, let's break this down because that's a lot of information and maybe some of this terminology seems intimidating. So we're going to break this down and we're going to say that NMR spectroscopy explores the interaction between electromagnetic radiation and the magnetic moments of nuclei.

So we're going to break this down by covering a couple of topics that we're going to use to build up this idea of NMR. This is going to be, first we're going to talk about magnetic moments and magnetic field alignment. Then we're going to talk about radio frequency irradiation and the energy gap. All right, we're going to call that EG for energy gap.

Then we're going to talk about resonance and absorption, all right, and absorption. Then we'll talk about detection, all right, and that requires us to talk about NMR spectra. And then finally, with all this knowledge, we can move into talking about analysis, all right. And for analysis here, we're going to have to understand things like chemical.

environment, all right, shielding amongst other things. All right, so that's our breakdown of how we want to talk about NMR spectroscopy to really understand it. Now, for the first topic, nuclear For magnetic moments and magnetic field alignment, nuclei of certain isotopes, they possess a property known as spin, which due to their charge generates a magnetic moment.

So you can think about them as like a tiny bar magnet. Now when you take these nuclei and they're placed in a strong magnetic field. all right, when you place them in a strong magnetic field, all right, their magnetic moments align in one of two ways. They can align with the field. All right, they can align with the field.

This is going to be the lower energy state, the alpha state, or they're going to align against the field, the higher energy state, the beta state. All right, now when we move into talking about radiofrequency, iridation, and energy gap, well, the energy difference between the alpha state and the beta state is very specific, and it depends on the strength of the external magnetic field and the type of nucleus. By applying radiofrequency pulses at a frequency that matches this energy gap, nuclei can then be excited from the alpha state to that beta state. And this then allows us to talk about resonance and absorption.

When the frequency of the radiofrequency radiation corresponds to the energy gap, Resonance occurs and the nuclei absorb the radiofrequency energy transitioning to that higher energy state, all right? Then what happens, all right, is that after excitation, nuclei eventually release the absorbed energy and return to the lower energy state, a process that's known as relaxation. The release energy is detected and transformed into a state of relaxation. into NMR signal. All right, now we could talk about analysis, and this results in us talking about chemical environment and shielding as well.

The exact frequency at which a nucleus resonates is affected by the electronic environment around it. Electrons can shield the nucleus from the external. magnetic field and different chemical environments are going to result in slightly different resonances, which is how NMR can distinguish between different types of atoms in a molecule.

And then when we get to Actually discussing analysis and interpretation, the NMR spectrum consists of peaks that correspond to different nuclei resonating at different frequencies. And by analyzing those peaks, scientists can infer the chemical structure of the molecule. Looking at an NMR spectra, we can talk about several things that are going to help us understand this spectra. Those things are chemical shift. The position of an NMR signal on the spectrum is called the chemical shift, and it is highly sensitive to the chemical environment of the nucleus.

We can also talk about integration. The area under an NMR peak reflects the number of nuclei that correspond to that signal. And then we can also talk about multiple structure.

The splitting pattern of an NMR signal provides information about the number of neighboring nuclei. All right, so when we talk about NMR spectra, all right, a typical NMR spectra is a plot of frequency versus absorption of energy. And because different NMR spectrometers operate at different magnetic field strengths, a standardized method of plotting the NMR spectrum has been adopted.

The standardized method, which is The only one that's seen on the MCAT and the only one that we're going to concern ourselves with uses an arbitrary variable called chemical shift, which with units of parts per million, all right, ppm. The chemical shift is plotted on the x-axis and it increases towards the left, which is referred to as downfield. To make sure that we know just how far downfield compounds are, we use tetramethylsilane, TMS, as the calibration standard to mark zero ppm.

When counting peaks, make sure to skip that TMS peak. Now nuclear magnetic resonance. is most commonly used to study H nuclei, right?

H1, hydrogen 1 nuclei, protons. And that is all that the MCAT will be testing for. So that is all that we are going to be concerning ourselves with. Now, here you can see things that you want to think about when you're looking at the spectra, number of signals, location of signals, area under signals, and the shape of the signals. We're going to be talking about these things.

Here in this video, we're going to talk about chemical shifts, integration, and multiplicity and coupling. Again, I want to reiterate that for a more in-depth analysis of this flowchart to understand NMR, I would highly recommend my Organic Chemistry 2 playlist, Chapter 15 is all about NMR. Here, of course, in the video, we're going to hyper-focus on the concepts that are high-yield test concepts, and we're not going to concern ourselves with too much. theory that is unnecessary for the MCAT. So we're going to start off here with looking at this NMR spectra for dichloromethylmethyl ether, and we're going to talk about interpreting the HNMR spectra for this compound.

All right, here we have it shown. All right, here we have it shown. Now, most hydrogen nuclei come into resonance anywhere between 0 to about 10 ppm downfield from that TMS peak. each distinct set of nuclei gives rise to a separate peak.

This means that if multiple protons are chemically equivalent, meaning they have the same magnetic environment, they will lead to the same peak. So for example, if we look at this figure here, all right, it depicts the HNMR of dichloromethylmethyl ether, which has two distinct sets of hydrogen nuclei. While it has four hydrogens, it only has two distinct hydrogens.

HA, this is the hydrogen that's attached to the carbon that has two chlorine groups. And this hydrogen, HB, that's attached to this carbon. All three of these hydrogens on this carbon are referred to as being chemically equivalent. They have the same magnetic environment. They are going to lead to the same peak.

All right, so the single proton... Attached to the dichloromethyl group HA is in a different magnetic environment from the three protons on the methyl group HB. So the two classes will resonate at different frequencies. Now the three protons on the methyl group are chemically equivalent.

They're going to resonate at the same frequency because this group rotates freely and on average each proton sees an identical magnetic environment. All right now the peak on the left all right this peak on the left right here I'm going to highlight it in blue. All right, it's referred to as A. This is from the single dichloromethyl proton.

And then the taller middle peaks that I'm going to highlight here in red, referred to as B. All right, these are from the three methyl protons. Now, the height of each peak is proportional to the number of protons it contains. Specifically, if we were to analyze the area under the peaks, called the integration, we would find that the ratio of peak A to peak B is about 1 to 3, corresponding exactly to the ratio of protons that produce each peak. This makes sense.

There is one hydrogen that is... associated to this dichloromethyl group, all right? And there are three equivalent HB protons.

And that makes sense. When you integrate the A peak and then the B peak, you have this one-to-three ratio, and that's because there is one HA proton to three HB protons, all right? Now that we know which peak is which, let's talk about their respective positions on the spectrum.

We can see that the peak for the single proton, the peak A, is fairly far downfield compared with the B peak. This is because it is attached to a carbon with two electronegative chlorine atoms and an oxygen. These atoms pull electron density away from the surrounding atoms, thus deshielding the proton. from the magnetic field. All right, the more the proton's electron density is pulled away, the less it can shield itself from the applied magnetic field, resulting in a further downfield reading.

Now, with the same reasoning, we know that if we had an electron donating group, such as a silicon atom in TMS, it would help shield the H nuclei and give it a position further upfield. This is why tetramethylsilane is used as the reference or calibration peak. Everything else in proton NMR will be more deshielded than it. All right.

Now, with that discussion, it becomes really important for us to talk about where we would expect certain features to appear in our NMR spectra. All right. And so here we see a table.

indicating the chemical shift ranges of several different types of protons. Now, if I was your friend, I would give you the advice that it is probably beneficial to you to kind of have a good understanding of all of these groups and where they would appear. However, if you're on a time crunch or you want to know what the high yield things to know in regards to the chemical shifts for protons in different environments for NMR, here are those groups that you should know. The ones that are most important are going to be the aldehydes and ketones, all right?

Make sure you know where you would see aldehydes on the NMR spectra, all right? Also, no carboxylic acid, okay? No aromatic rings where they would appear, all right? Also, different hybridized carbons.

So know where a sp3 carbon would appear, an sp2 carbon would appear, and an sp carbon would appear. As well as the range for alcohols. And honestly, that pretty much encompasses everything that we're seeing here anyways. So really, all of these groups are extremely important to know.

Now, once you have your chemical shifts, down, once you know where you would expect different features to be on your NMR spectra, and you understand how integration gives you this ratio relationship of different groups for the different peaks, the next thing that you want to talk about is multiplicity. In NMR, peaks tend to have distinct shapes called the peak multiplicity. Multiplicity, or in other words, coupling, is a view on the environment.

that a hydrogen resides in. It reveals how many hydrogens are on the next carbon in the structure. So when you look at NMR, multiply Multiplicity is defined by the number of peaks in the signal.

Two questions we should ask about these peaks and multiplicity are, one, why do we get multiplicity? What is the cause of this peak splitting we are observing? All right, and two, what does it mean? To answer the first question, a signal's multiplicity is the consequential result of the magnetic effects of neighboring hydrogens. And so then to answer the second question, what does it mean?

It indicates the number of neighboring protons, and as a consequence, allows us to build an understanding of the framework of a molecule. Remember, we use HNMR to get the carbon-hydrogen framework because nuclei with odd number of protons have something called nuclear spin. and this means that the nuclei rotates and causes a magnetic field around itself called the magnetic moment.

When there are other neighboring nuclei like that, the magnetic effects of each will interact with each other in a molecule. This signal's multiplicity is the result of the magnetic effects of neighboring protons and therefore indicates the number of neighboring protons. So to illustrate this concept, let's consider the following examples.

All right, if you have a molecule like this, all right, and you have these two protons, HA, HB, if HA and HB are not equivalent to each other, they will produce different signals. Let's focus on HA. All right, let's focus on HA.

In some molecules, all right, HB will be aligned with the field, while in other molecules, HB will be aligned against the field. As a result, the chemical shift of HA in some molecules will be slightly different than the chemical shift of HA in other molecules, resulting in the appearance of two peaks for HA. In other words, this presence of HB. B splits the signal for HA into a doublet. So HA will appear as a doublet in the NMR spectrum.

All right, if you have this molecule now where you have HA here on this carbon and on this neighboring carbon, you have two hydrogens, HB hydrogens. All right, what would you expect? Well, you can have both of those HB protons that align against the field.

both that align with the field, or you can have a mixture of align or not align for these HB protons. What that means is that these HB protons are going to split the signal for HA into a triplet. So HA appears as a triplet, all right, because of the splitting that's caused by these two HB protons, all right? And again, we can look at this one where there are... There's your HA signal that you're concerned with, and neighboring it is a carbon that has three HB protons.

All three can align with the field, all three can align against the field, and you can have a mixture of align and not align. What happens here is that the presence of these three HB protons splits the signal for HA into a quartet. There is a very...

clear pattern that's happening here. When you are looking at HA or any proton, all right, and you're trying to figure out its peak multiplicity based off of the number of neighboring protons, that is going to be equal to N plus 1. The peak multiplicity of HA is going to be equal to the number of neighboring protons, N plus 1. And so in this scenario, that's going to equal 2. Hence why we see that HA appears as a doublet, two peaks, two peak splits. All right, for this scenario, the HA peak is going to have N plus 1. It has two neighboring hydrogens.

Then you add plus 1. That gives you a 3. Hence why we see HA appears as a triplet. And then again for this scenario, HA equals number of... proton neighbors, that's three for HB plus one, that gives you four. Hence why HA appears as a quartet in your NMR signal.

All right, so the way to know what the multiplicity of a hydrogen is, is you can count the number of neighboring hydrogens, then add one. So if a hydrogen has three neighboring hydrogens, It's going to have a multiplicity of 3 plus 1, which is equal to 4. It's going to be a quartet. And so here we've talked about a lot of elements that we can put together to really understand NMR.

All right. Knowing how many unique hydrogen signals you have and the chemical shift of each. Then you have integration. All right. And multiplicity.

And all of these play a role into your NMR spectrum. All right, all of these are really important in reading and interpreting a NMR spectrum. All right, chemical shifts give you where you would expect to have a signal.

All right. Integration is the area under the curve, and this is proportional to the number of protons contained under the peak. And then you have multiplicity, which gives you an understanding of your environment. How many neighboring hydrogens do you have that are interfering with your signal?

That results in this signal splitting. All right. That's everything we need to know conceptually about NMR. And in the previous video, we did IR and UV. So now we've covered everything we need to know about spectroscopy for the MCAT.

In the following video, we're going to tackle a practice problem set. Let me know if you have any questions, comments, concerns down below. Other than that, good luck, happy studying, and have a beautiful, beautiful day, future doctors.

Transcript for:NMR Spektroskopisi ve Analiz Yöntemleri

Transcript for:
NMR Spektroskopisi ve Analiz Yöntemleri