Organic Chemistry 2323 (Structure & Bonding)

Single Bond

A chemical bond in which one pair of electrons is shared between two atoms.

Double Bond

A chemical bond in which two pairs of electrons are shared between two atoms.

Sigma Bond

The strongest type of covalent chemical bond. They are formed by head-on overlapping between atomic orbitals.

Pi Bond

Covalent chemical bonds where two lobes of an orbital on one atom overlap two lobes of an orbital on another atom and this overlap occurs laterally. Each of these atomic orbitals has zero electron density at a shared nodal plane, passing through the two bonded nuclei.

SP3 Hybridization

the formation of a hybrid orbital from one 2s and three 2p orbitals

109.5 Degrees

Steric Number

The number of atoms bonded to the central atom of a molecule plus the number of lone pairs on the central atom. It is often used in VSEPR theory in order to determine the particular shape, or molecular geometry, that will be formed.

VSPER Theory

A model used in chemistry to predict the geometry of individual molecules from the number of electron pairs surrounding their central atoms. It is also named the Gillespie-Nyholm theory after its two main developers, Ronald Gillespie and Ronald Nyholm.

SP2 Hybridization

One of a set of hybrid orbitals produced when one s orbital and two p orbitals are combined mathematically to form three new equivalent orbitals oriented toward the corners of a triangle

120 Degrees

SP Hybridization

when one s and one p orbital in the same main shell of an atom mix to form two new equivalent orbitals

180 Degrees

Angstroms

A unit of length equal to 10−10 meters (that is, one ten-billionth of a meter), approximately the size of an atom, and denoted by the symbol Å, used especially to measure the wavelength of electromagnetic radiation or distances between atoms.

Bond Line Structure

A representation of molecular structure in which covalent bonds are represented with one line for each level of bond order.

Isomers

Two or more compounds with the same formula but a different arrangement of atoms in the molecule and different properties.

Electronegativity

A measure of the tendency of an atom to attract a bonding pair of electrons. The Pauling scale is the most commonly used.

Dipole

Usually refers to the separation of charges within a molecule between two covalently bonded atoms or atoms that share an ionic bond.

Polar

Bonds that are partly ionic

Nonpolar

When the electronegativities of the two atoms are equal.

Intermolecular Forces

The forces which mediate interaction between molecules, including forces of attraction or repulsion which act between molecules and other types of neighboring particles, e.g. atoms or ions.

London Dispersion Forces

Is a temporary attractive force that results when the electrons in two adjacent atoms occupy positions that make the atoms form temporary dipoles. This force is sometimes called an induced dipole-induced dipole attraction. (Weakest Force)