Chapter 1
Electrons that are in the outermost shell
Valence electrons
Hydrocarbons containing only single bonds.
Alkanes
One of six bonds on the chair conformation of the cyclohexane ring that point up or down.
Axial
A conformation with a 60o dihedral angle between the largest groups.
Gauche
An alkane containing a ring of carbon atoms.
Cycloalkane
A covalent bond in which electrons are shared unequally.
Polar covalent bond
The forces between polar molecules resulting from the attraction of their permanent dipole moment.
Dipole-dipole forces
The interference between two bulky groups that are so close together that their electron clouds experience a repulsion.
Steric strain
The most stable conformation of cyclohexane, with one part puckered upward and another part puckered downward.
Chair
Structures that are related by rotations about single bonds.
Conformations
A covalent bond that involves the sharing of two pairs of electrons
Double bond
Isomers whose atoms are connected differently; they differ in their bonding sequence.
Constitutional/structural isomers
A conformation with a 0o dihedral angle between the largest groups. Usually the highest-energy conformation.
Totally eclipsed
The angle between two specified groups in a Newman projection
Dihedral
Process of separating compounds based on boiling points
Distillation
A shorthand structural formula with bonds represented by lines. Carbon atoms are implied wherever two lines meet or a line begins or bends. Atoms other than C and H are drawn in. Each carbon atom is assumed to have enough hydrogens to give it four bonds.
Line-angle formula
The geometry of sp2 orbitals that are separated by bond angles of 120O
Trigonal planar
The strain associated with eclipsing of bonds in a conformation
Torsional strain
Strain that results from resistance to twisting
Torsional strain
A side chain or appendage on the main chain that replaces a hydrogen.
Substituent
A molecule or ion for which two or more valid Lewis structures can be drawn, differing only in the placement of the valence electrons.
Resonance hybrid
Isomers that differ only in how their atoms are oriented in space
Stereoisomers
A way of drawing the conformations of a molecule by looking straight down the bond connecting two carbon atoms.
Newman projections
The strong steric strain between two axial groups on cyclohexane carbons with one carbon between them.
1,3-diaxial interaction
Heating large alkanes to cleave them into smaller molecules.
Cracking