The infrared spectrum of CH3CH2NH2 shows two absorptions not shown by bromoethane. Identify the bonds responsible for these absorptions.
I'm a spectroscopist, but not a chemist. Here's my best guess.
The CH3CH2NH2 has a NH2 group where a Br would be in bromoethane. The NH2 is probably connected to the C2H5 with a C-N bond. There would also be a N-H stretch bond showing up in the IR spectrum.
:D thank you
right on!
Yes, you are correct! The infrared (IR) spectrum of CH3CH2NH2, also known as ethylamine, shows two absorptions that are not observed in bromoethane. These absorptions can be attributed to the presence of the NH2 group in ethylamine.
In ethylamine, the NH2 group is connected to the C2H5 group through a C-N bond. This C-N bond is responsible for one of the absorptions observed in the IR spectrum.
The C-N bond in ethylamine is polarized due to the difference in electronegativity between carbon and nitrogen. This polarization results in a dipole moment, which causes the C-N bond to have a characteristic stretching motion. This stretching motion, often referred to as a C-N stretch, occurs at a specific frequency in the infrared spectrum, resulting in an absorption peak.
Additionally, ethylamine possesses a N-H bond within the NH2 group. The N-H bond also exhibits a characteristic stretching motion, referred to as an N-H stretch, which occurs at a different frequency from the C-N stretch and results in a second absorption peak.
Therefore, the two absorptions observed in the IR spectrum of ethylamine, but not in bromoethane, can be attributed to the C-N bond and the N-H bond present in the NH2 group of ethylamine.
I hope this explanation clarifies your question! If you have any more doubts or need further assistance, feel free to ask.