Action of Proton in a Molecule

Protons in a Molecule Depending on their chemical environment, protons in a molecule are shielded by different amounts. More Shielded, H absurb at a higher a tr - field : H less shillded, absorbs at a lower field Proton NMR Number Different kinds of Protons. location Shielded / dishielded. Intensity No: of Protons of that type. Splitting No, of Protons on adjacent atoms. Chemical Shift Chemical shift, is a measure of the degree to which a nucleu in a molecule is Shielded Factors affecting are Electronegativity of nearby atoms. Hybridization of adjacest atoms. Diamagnetic effects.

Paramagnetic effects Solvent effect , Standard for Chemical Shift In NMR spectroscopy / the standard is often tehamethylsilane, S1 ((113)4 ,abbreviated , TMs. It is not she elded Tetramethyl Silane (TMS) is used as reference because it is Soluble in most organic solvents, , is inert, volatile and has 12 equivalent 1H and 4 equivalent 13c. TMS signal is set to O. (He H3C- - Si- CH3 Sillum, CH3 Shielding A Proton surrounded by electron densky nucleus issued Mag field induced B, by the e (opposite to 2000 Bo) The nucleus " jeels" Boonly Bo The induced field decreases the strength of the magnetic field' " fets" by. the nucleur This nucleus is shielded 3