By looking at a mass spectrum of a compound, we can deduce information on the possible molecular formulas and molecular weights of compounds. Mass spectrums also produce peaks because of fragmentation, which can actually help us discover the compound and its true structure. It is important to note that the some fragments produced in a mass spectrometer are charged and some are uncharged. However, only the positively charged ions are analyzed by the mass spectrometer. It is important that there be a vacuum inside the mass spectrometer because it is needed to remove the uncharged fragments from the machine. Only charged particles end up getting read on the mass spectrum. One task that mass spectrometry spectrometry is great at is distinguishing different isotopes of an element. This is especially true of chlorine, since the relative abundance of its isotope is at a high number of 32.0. By using this information, we can look for peak relationships relationships based on the relationships relationships of the relative abundances of the isotopes. Before looking at the mass spectrum of p-chlorobenzophenone, p-chlorobenzophenone, we should know what the difference is between the base peak and the parent ion peak. The most intense peak peak of the spectrum spectrum is actually known known as the base peak. The parent ion peak peak is the most significant significant peak peak with the highest highest mass on the spectrum. Now looking at the mass spectrum of p-chlorobenzophenone, p-chlorobenzophenone, we can identify the base peak at m/z 105. The parent ion peak is the peak at m/z 216. There are no molecular mass fragments that correspond to the base peak or the molecular ion peak. By looking at m/z = 77, 105, 111, and 139, we can determine if there are any molecular mass fragments that correspond to those peaks. For m/z= 105, the molecular mass fragment is C7H5O. The other fragment originally attached to it is at m/z = 111. The fragment is C6H4Cl. For m/z = 77, the molecular mass fragment is C6H5. The corresponding fragment attached to it is C7H4OCl at m/z = 139. Now the peaks at m/z = 113, 141, and 218 are M + 2 peaks due to the presence of a chlorine chlorine atom. These These peaks (M + 2) are are 1/3 the size of the the corresponding corresponding original M peaks (111, 139, and 216). This is because the relative abundance of 37Cl is 32.0, compared to the relative abundance of regular 35Cl of 100. The m/z values of the M + 2 peaks are off by a value of 2 because 37Cl is 2 AMUs bigger than 35Cl. You can see that we previously discovered that m/z = 111 and 139 have Cl in the fragment. 216 is the molecular ion peak, which is the whole molecule containing Cl: C13H9OCl. The peak at m/z = 218 is due to the M + 2 peak peak of chlorine.
NOTE: With the exception of the MOST ABUNDANCE isotopes such as "12C"; "1H" and "16O", your molecular mass fragment MUST include the specific isotopic mass for the element in your text. In other words, by default, the symbol "C" represents "12C". The symbol "H" corresponds to "1H". The symbol "O" represnts "16O". Atoms other than "C","O" and "H" must have their corresponding isotopic masses labeled properly. For example, you should specify the specific isotope of chlorine atom by using either 35Cl or 37Cl in your text. For carbon, you should use 13C to represent the carbon 13 isotope.
In your essay, be sure to maintain the strucutral components of the molecule when formatting the molecular ion identity. For example, the mass spectrum of isopropyl alcohol gives a base peak at m/z = 45. This should be written as being due to [CH3CHOH]+, not [C2H5O]+ ion. For molecular mass fragment containing benzene ring, you may use [C6Hx]+ to represent the benzene ring fragment. For example, for a mono-substituted benzene ring, you will write [C6H5]+ to represent the molecular mass fragment corresponds to the benzene ring.
By looking at a mass spectrum of a compound, we can deduce information on the possible molecular formulas and molecular weights of compounds. Mass spectrums also produce peaks because of fragmentation, which can actually help us discover the compound and its true structure.
It is important to note that the some fragments produced in a mass spectrometer are charged and some are uncharged. However, only the positively charged ions are analyzed by the mass spectrometer. It is important that there be a vacuum inside the mass spectrometer because it is needed to remove the uncharged fragments from the machine. Only charged particles end up getting read on the mass spectrum.
One task that mass spectrometry is great at is distinguishing different isotopes of an element. This is especially true of chlorine, since the relative abundance of its isotope, 37Cl, is at a high number of 32.0. By using this information, we can look for peak relationships based on the relationships of the relative abundances of the isotopes.
Before looking at the mass spectrum of p-chlorobenzophenone, we should know what the difference is between the base peak and the parent ion peak. The most intense peak of the spectrum is actually known as the base peak. The parent ion peak is the most significant peak with the highest mass on the spectrum.
Mass spectrums are incredibly useful for analysis and can tell us a great deal about molecular weight, formula, and structure.
Now looking at the mass spectrum of p-chlorobenzophenone, we can identify the base peak at m/z 105. The parent ion peak is the peak at m/z = 216. There are no molecular mass fragments that correspond to the base peak or the molecular ion peak.
By looking at m/z = 77, 105, 111, and 139, we can determine if there are any molecular mass fragments that correspond to those peaks. For m/z= 105, the molecular mass fragment is [C6H5CO]+. The other fragment originally attached to it is at m/z = 111. The fragment is [C6H4Cl]+. For m/z = 77, the molecular mass fragment is [C6H5]+. The corresponding fragment attached to it is [C6H4CClO]+ at m/z = 139.
Now the peaks at m/z = 113, 141, and 218 are M + 2 peaks due to the presence of a chlorine atom. These peaks (M + 2) are 1/3 the size of the corresponding original M peaks (111, 139, and 216). This is because the relative abundance of 37Cl is 32.0, compared to the relative abundance of the more common 35Cl value of 100. The m/z values of the M + 2 peaks are off by a value of 2 because 37Cl
is 2 AMUs bigger than 35Cl. You can see that we previously discovered that m/z = 111 and 139 have Cl in the fragment. 216 is the molecular ion peak, which is the whole molecule containing Cl: C13H9OCl. The peak at m/z = 218 is due to the M + 2 peak of chlorine.
