Illustrated Glossary of Organic Chemistry

Pentet (quintet): In NMR spectroscopy, a split signal composed of five lines, close together. The height of the lines will be close to a 1:4:6:4:1 ratio.

Idealized pentet
Lines in a 1:4:6:4:1 ratio
"Leaning" pentet

  This simulated 1H-NMR spectrum of sec-butyl ether has a pentet at 1.44 ppm due to the molecule's CH2 group. Click image for a larger version.