Multiple Bonds, Pi MOs, Delocalization
Permanganate Test Results
Hexane, C6H14
Hexene, C6H12
Limonene
BlankPinene, C10H16
Trigonal Planar Electron Group Geometry
Methanal (Formaldehyde)
Ethene
(Ethylene)
120o
Perfect Trigonal Planar Arrangement
Bond Angles Deviate From 120o
Methanal (Formaldehyde)Ethene (Ethylene)
Two Models for Ethene
Sigma Bonding Orbital Between C Atoms in Ethene
Pi Bonding Orbital Formation at C Atoms in Ethene
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
The Double Bond in Ethene
sigma orbitalfor first part
of bond
pi orbitalfor second
part of bond
The Sigma Framework in Ethene
The Pi Bond in Ethene
The 5 Sigma and 1 Pi Bonding Orbitals in Ethene
IsomerismSame number, kind of atoms
Different connectivity
Non-superimposable mirror images
Same connectivity but different spatial arrangement
e.g., cis,trans
Isomers
Structural Isomers
Stereoisomers
Geometric Isomers
Optical Isomers
Conformational Isomers
Interconvert by sigma bond rotation
Cis-Trans Isomerism
Trans Cis
Interconversion Requires Breaking the Pi Bond
Conformational Isomerism
Interconversion Requires Only Sigma Bond Rotation
Same Molecule, Just Different Rotations
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
1,2-dichloroethane