OChem 2 : CH15 Terms

Chemical Shift

location of signal (ppm) on x-axis

• gets more info on environment of proton

Integration

Number of protons being represented by the signal

• will add up to Hs in compound

Splitting Pattern

Shape of signal

Downfield/ Downshielded

Experiences a magnetic field that is more than the instrument

• closer to electronegative atoms and electron density

Upfield/ Shielded

Experiences a magnetic field that is less than the instrument

TMS

Internal Standard = 0 ppm

• not part of the compound being analyzed

Monosubstituted Rings

• integration of 5Hs in aromatic region

• ideally has 3 signals - but overlaps so looks like one signal

Disubstituted Ring

• integration of 4Hs in aromatic region

• has 2 substitutions on ring (A and B)

• 3 Options

“ortho” option

• 4 signals

• Each signal integrating for H

  • 2 doublets (dd)

  • 2 triplets (tt)

“meta” option

• 4 signals

• Each signal integrating for H

  • 2 doublets (dd)

  • 1 triplet (t)

  • 1 singlet (s)

“para” option

• 2 signals

• Each signal integrating for 2Hs

Complex Splitting

Using more sensitive instrument/stronger magnet to differentiate types of neighbors in a splitting pattern.

H₂O Exhange

• will exchange with acidic Hs

  • OH

  • Carboxylic Acids

  • amines/amides

• dissolves in a deuterated solvent, which replaces an H

Deuterated Solvent

Solvents that are isotopes of H are used to ensure that we are seeing signals from ONLY our compound in HNMR.