Question

CH3 Cl 100 Base 10) The El-MS of 2-chloro-2- methylpropane is shown at right. Draw the structure of the cation corresponding to the base peak. Clearly indicate where the charge resides. You need only show one of the two resonance forms. MS-NW-1505 no parent ion detected 92- Relative Intensity 10 15 20 25 30 35 40 55 60 65 70 75 80 45 50 m/z The 3:1 ratio of peak intensities at 77 and 79 m/z in the El-MS above is due to which specific isotopes? | 35 cl and ² cl

Answer 1

2-chloro-2-methyl propane : Hz ce 0-2-methyl propane: [Mt. Molecular ion : x Easier to remove non bonding *cation corresponding to electron. Hence removal from co. the base peak (m/2=57) is formed by C-X cleavage , where x is ce atom. - m/2 = 57 CH3 3 cation is formed : H₂C-6-CH3 m2 57 (Base peak)

3:1 ratio of peak intensities is characteristic of Chlorine atom, which has two isotopes. Cl-35 and Cl-37