The signal at 0.9 ppm in the 1H NMR spectrum corresponds to aliphatic protons.
In proton nuclear magnetic resonance (1H NMR) spectroscopy, chemical shifts provide information about the local electronic environment of hydrogen atoms in a molecule. The chemical shift is expressed in parts per million (ppm) and helps identify the type of protons contributing to a specific signal.
The signal at 0.9 ppm in the 1H NMR spectrum typically corresponds to aliphatic protons. Aliphatic protons are those attached to sp3 hybridized carbon atoms, commonly found in saturated hydrocarbons and aliphatic chains of organic compounds. The lower chemical shift value indicates a relatively shielded environment for these protons, likely due to their association with carbon atoms that are not directly connected to electronegative elements or aromatic systems.
Therefore, based on the chemical shift of 0.9 ppm, it is reasonable to infer that the protons generating this signal are aliphatic in nature, providing valuable information about the molecular structure and the local electronic environment of these specific hydrogen atoms in the compound under analysis.