User:CompuHacker/CHLewis

This is a gallery of Lewis structures in 3-D.

Carbon-Hydrogen covalent bond styles

These pictures are 3D Lewis type representations of the carbon-hydrogen bond using different ways of representing the molecule. The rotation is meant to help in visualizing the 3D structure of the molecule.

Space Filled (Carbon - 77pm radius, Hydrogen - 53pm radius)

"see through" Valence Shell

Hydrogen Covalent bonds

In a covalent or two center bond, one electron from the hydrogen drops into the hole of the other element and one electron from the element drops into the hydrogen hole. Distances are in picometers.

Hydrogen 74pm
Carbon 109pm
Nitrogen 101pm
Oxygen 96pm

If we fill up all the available holes, the molecules become methane from carbon, ammonia from nitrogen and water from oxygen.

File:Water99b.PNG

Other types of bonding

Carbon bonding and the Hydrocarbons

C-C Covalent 154pm

C-C Aromatic 144pm

C-C Double 134pm

In a covalent or two center bond, one electron from each carbon drops into the hole of the other. Other forces keep the elements from being pulled furthur together.
For the aromatic bond, one electron drops into a hole of the other carbon and the two closest holes par up with two electrons from the other carbon.
The double covalent bond involves four centers, with two electrons and two holes from each carbon.

Hydrocarbons are made up of hydrogen and carbon molecules bound together in a variety of ways. When you mix hydrogen molecules with carbon molecules, the relative concentrations are very important. Examples of covalent carbon bonds include ethane, the long octane and the round cyclohexane. A ratio of three hydrogen to one carbon will produce a lot of ethane. A ratio closer to two hydrogen to one carbon will produce more of the longer octane.

Examples of the aromatic and double covalent can be found in the pictures of ethylene (left) and the circular benzene below.

Oxygen covalent bonding for alcohols and sugars

C-O Covalent 143pm

Methanol

Ethanol

A hydrocarbon with a single oxygen-hydrogen bond (a hydroxide, OH for short) on the end is called an alcohol. Two common alcohols methanol and ethanol are examples. Glycerol is a collection of three OH hydroxides stuck to a short carbon chain and can be used to link two or three of the long hydrocarbons to create lipids. The sugar (glucose), acts as a storage facility for the OH bonds.

Glycerol
Glucose

Alpha Glucose is in a ring structure and flattened out. These combine to become starches and cell coatings. Beta Glucose becomes plant cellulose.

AlphaGlucose Ring (front view)
AlphaGlucose Ring (side view)

Oxygen double covalent bonding for acids

C-O Double 135pm

Formic Acid

Acetic Acid

An organic acid is a hydrocarbon molecule with a with two oxygens and a hydrogen on the end. The hydrogen proton easily comes off forming an acid at that end of the molecule. The simpliest are Formic acid, acetic acid (vinegar). Citric acid acts as a storehouse of this type of bond.

Citric Acid

Long hydrocarbon acid chains are called fatty acids. Palmitic and Oleic acids form the basis of lipids, the main building block of biological cell walls.

Lauric Acid
Palmitic Acid
Oleic Acid

Nitrogen bonding for Amino and Nucleic acids

C-N Covalent 147pm

Nitrogen with its different charge adds enormous diversity to the structures that can be built. The most important are the structure molecules called amino acids. Proteins are large organic structures built from amino acids. The fundamental binding property of amino acids is to have the 'amino' end of one molecule (where the nitrogen is) bind to the 'acetic' end of the next molecule.

Nitrogen also gives molecules the flexibility to build nucleic acids. This allows information to be encoded, stored and passed on to future generations using the DNA binding code.

Amino acid Glycine bonding with Alanine
Nucleic acid A-DNA bonded to T-DNA

References

Virtual Textbook of Organic Chemistry Electron Configurations