CHEM 222 Lecture Notes - Lecture 8: Topicity, Chemical Formula, Chemical Shift

• School: McGill University
• Department: Chemistry
• Course: CHEM 222
• Professor: Laura Pavelka

Document Summary

Recognize nmr active nuclei based on nuclear spin values and/or mass number. Explain the effect of an external magnetic field on a nucleus and property of resonance. Know the factors that affect resonance frequency. Explain how shielding affects resonance frequencies for the same type of element in a molecule (i. e. the general changes based on electronic environment) Know the basics of the two general methods for collecting an nmr spectrum (fix bo or fix breal) Understand the foundations of chemical shifts, integration values, and splitting patterns. Use an 1h and 13c nmr spectra to elucidate the structure of an unknown, given at least a molecular formula. Differentiate between homotopic, enantiotopic, diastereotopic, heterotopic nuclei. Understand basics of ms theory (ionization and fragmentation of functional groups) Use a mass spectra to help elucidate the structure of an unknown (find molecular weight/formula) Recognize isotope patterns for c, s, cl, br. Use nitrogen/even electron rule to differentiate fragments from m+ and determine even/odd.