CHM247H1 Study Guide - Midterm Guide: Wavenumber, Alkyne, Cyclopentene
Document Summary
Degrees of unsaturation y number of multiple bonds or rings in a structure y formula for saturated acyclic compound is cnh2n+2 y each ring or multiple bond replaces 2 h s y formal formula: . , where i is the number of that atom in the formal and vi is the bonding capacity for h y. Informal rules: halogens replaces hydrogen, oxygen doesn t affect hydrogen count, nitrogen means to subtract one hydrogen from count. Ir energy absorption relates to stretch and bending of bonds: symmetric or anti-symmetric stretch. In plane or out of plane stretch y dipole moment change required during vibration for ir absorption y. one spike per hydrogen; in the 900s: also a c=c spike(1640-1680) in fingerprint region above the c-c spikes if double bond is terminal. If not terminal; dipole moment is not strong enough y alkynes: sp1 hybrid means a wavenumber far above 3000.
